Atmosphere

18 pages, 4313 KiB

Open AccessEditor’s ChoiceArticle

Carbonaceous Aerosol in Polar Areas: First Results and Improvements of the Sampling Strategies

by Laura Caiazzo, Giulia Calzolai, Silvia Becagli, Mirko Severi, Alessandra Amore, Raffaello Nardin, Massimo Chiari, Fabio Giardi, Silvia Nava, Franco Lucarelli, Giulia Pazzi, Paolo Cristofanelli, Aki Virkkula, Andrea Gambaro, Elena Barbaro and Rita Traversi

Atmosphere 2021, 12(3), 320; https://doi.org/10.3390/atmos12030320 - 28 Feb 2021

Cited by 3 | Viewed by 2736

Abstract

While more and more studies are being conducted on carbonaceous fractions—organic carbon (OC) and elemental carbon (EC)—in urban areas, there are still too few studies about these species and their effects in polar areas due to their very low concentrations; further, studies in [...] Read more.

While more and more studies are being conducted on carbonaceous fractions—organic carbon (OC) and elemental carbon (EC)—in urban areas, there are still too few studies about these species and their effects in polar areas due to their very low concentrations; further, studies in the literature report only data from intensive campaigns, limited in time. We present here for the first time EC–OC concentration long-time data records from the sea-level sampling site of Ny-Ålesund, in the High Arctic (5 years), and from Dome C, in the East Antarctic Plateau (1 year). Regarding the Arctic, the median (and the interquartile range (IQR)) mass concentrations for the years 2011–2015 are 352 (IQR: 283–475) ng/m³ for OC and 4.8 (IQR: 4.6–17.4) ng/m³ for EC, which is responsible for only 3% of total carbon (TC). From both the concentration data sets and the variation of the average monthly concentrations, the influence of the Arctic haze on EC and OC concentrations is evident. Summer may be interested by high concentration episodes mainly due to long-range transport (e.g., from wide wildfires in the Northern Hemisphere, as happened in 2015). The average ratio of EC/OC for the summer period is 0.05, ranging from 0.02 to 0.10, and indicates a clean environment with prevailing biogenic (or biomass burning) sources, as well as aged, highly oxidized aerosol from long-range transport. Contribution from ship emission is not evident, but this result may be due to the sampling time resolution. In Antarctica, a 1 year-around data set from December 2016 to February 2018 is shown, which does not present a clear seasonal trend. The OC median (and IQR) value is 78 (64–106) ng/m³; for EC, it is 0.9 (0.6–2.4) ng/m³, weighing for 3% on TC values. The EC/OC ratio mean value is 0.20, with a range of 0.06–0.35. Due to the low EC and OC concentrations in polar areas, correction for the blank is far more important than in campaigns carried out in other regions, largely affecting uncertainties in measured concentrations. Through the years, we have thus developed a new sampling strategy that is presented here for the first time: samplers were modified in order to collect a larger amount of particulates on a small surface, enhancing the capability of the analytical method since the thermo-optical analyzer is sensitive to carbonaceous aerosol areal density. Further, we have recently coupled such modified samplers with a sampling strategy that makes a more reliable blank correction of every single sample possible. Full article

(This article belongs to the Special Issue Chemical-Physical and Optical Properties of the Aerosol in Europe and the Arctic)

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30 pages, 39088 KiB

Open AccessEditor’s ChoiceArticle

Multi-Radar Analysis of the 20 May 2013 Moore, Oklahoma Supercell through Tornadogenesis and Intensification

by Clarice N. Satrio, David J. Bodine, Robert D. Palmer and Charles M. Kuster

Atmosphere 2021, 12(3), 313; https://doi.org/10.3390/atmos12030313 - 28 Feb 2021

Cited by 3 | Viewed by 3358

Abstract

A multi-radar analysis of the 20 May 2013 Moore, Oklahoma, U.S. supercell is presented using three Weather Surveillance Radars 1988 Doppler (WSR-88Ds) and PX-1000, a rapid-scan, polarimetric, X-band radar, with a focus on the period between 1930 and 2008 UTC, encompassing supercell maturation [...] Read more.

A multi-radar analysis of the 20 May 2013 Moore, Oklahoma, U.S. supercell is presented using three Weather Surveillance Radars 1988 Doppler (WSR-88Ds) and PX-1000, a rapid-scan, polarimetric, X-band radar, with a focus on the period between 1930 and 2008 UTC, encompassing supercell maturation through rapid tornado intensification. Owing to the 20-s temporal resolution of PX-1000, a detailed radar analysis of the hook echo is performed on (1) the microphysical characteristics through a hydrometeor classification algorithm (HCA)—inter-compared between X- and S-band for performance evaluation—including a hail and debris class and (2) kinematic properties of the low-level mesocyclone (LLM) assessed through

Δ V_{r}

analyses. Four transient intensifications in

Δ V_{r}

prior to tornadogenesis are documented and found to be associated with two prevalent internal rear-flank downdraft (RFD) momentum surges, the latter surge coincident with tornadogenesis. The momentum surges are marked by a rapidly advancing reflectivity (

Z_{H}

) gradient traversing around the LLM, descending reflectivity cores (DRCs), a drop in differential reflectivity (

Z_{D R}

) due to the advection of smaller drops into the hook echo, a decrease in correlation coefficient (

ρ_{h v}

), and the detection of debris from the HCA. Additionally, volumetric analyses of

Z_{D R}

and specific differential phase (

K_{D P}

) signatures show general diffusivity of the

Z_{D R}

arc even after tornadogenesis in contrast with explosive deepening of the

K_{D P}

foot downshear of the updraft. Similarly, while the vertical extent of the

Z_{D R}

and

K_{D P}

columns decrease leading up to tornadogenesis, the phasing of these signatures are offset after tornadogenesis, with the

Z_{D R}

column deepening the lagging of

K_{D P}

. Full article

(This article belongs to the Special Issue Radar Applications for Severe Weather Understanding and Nowcasting)

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19 pages, 10650 KiB

Open AccessEditor’s ChoiceArticle

Assessment and Improvement of Two Low-Cost Particulate Matter Sensor Systems by Using Spatial Interpolation Data from Air Quality Monitoring Stations

by Chen-Jui Liang and Pei-Rong Yu

Atmosphere 2021, 12(3), 300; https://doi.org/10.3390/atmos12030300 - 25 Feb 2021

Cited by 6 | Viewed by 2754

Abstract

Two low-cost fine particulate matter (PM_2.5) sensor systems have been established by the government and community in Taiwan. Each system combines hundreds of PM_2.5 sensors through an Internet of Things architecture. Since these sensors have not been calibrated, their performance [...] Read more.

Two low-cost fine particulate matter (PM_2.5) sensor systems have been established by the government and community in Taiwan. Each system combines hundreds of PM_2.5 sensors through an Internet of Things architecture. Since these sensors have not been calibrated, their performance has been questioned. In this study, the spatial interpolation data from air quality monitoring stations (AQMSs) was used to quantify the performances of the two sensor systems. The linearity, sensitivity, offset, precision, accuracy, and bias of the two sensor systems were estimated. The results indicate that the linearity of the government’s sensor system was higher than that of the community sensor system. However, the sensitivity of the government’s system was lower than that of the community system. The relative standard deviation, relative error, offset, and bias of the community sensor system were higher than those of the government sensor system. However, the government sensor system exhibited superior spatial interpolation results for the AQMS data than the community sensor system did. The precision and accuracy of the two sensor systems were poor during a period of low PM_2.5 concentrations. A working platform of improvements consisting of monitoring the operation loop and automatic correction loop is proposed. The monitoring operation loop comprises five modules, namely outlier detection, temporal anomaly analysis, spatial anomaly analysis, spatiotemporal anomaly analysis, and trajectory analysis modules. The automatic correction loop contains spatial interpolation module, a sensor performance detection module, and a correction module. The proposed working platform can enhance the performance of low-cost sensor systems, especially as alert systems for reportable events. Full article

(This article belongs to the Section Atmospheric Techniques, Instruments, and Modeling)

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13 pages, 1884 KiB

Open AccessEditor’s ChoiceArticle

Source Apportionment and Toxic Potency of Polycyclic Aromatic Hydrocarbons (PAHs) in the Air of Harbin, a Cold City in Northern China

by Haitao Liu, Bo Li, Hong Qi, Lixin Ma, Jianzhong Xu, Minling Wang, Wenwen Ma and Chongguo Tian

Atmosphere 2021, 12(3), 297; https://doi.org/10.3390/atmos12030297 - 25 Feb 2021

Cited by 12 | Viewed by 2911

Abstract

A total of 68 PUF samples were collected seasonally from 17 sampling sites in Harbin, China from May 2016 to April 2017 for analyzing 15 congeners of gaseous polycyclic aromatic hydrocarbons (Σ₁₅PAHs). An improved non-negative matrix (NMF) model and a positive [...] Read more.

A total of 68 PUF samples were collected seasonally from 17 sampling sites in Harbin, China from May 2016 to April 2017 for analyzing 15 congeners of gaseous polycyclic aromatic hydrocarbons (Σ₁₅PAHs). An improved non-negative matrix (NMF) model and a positive matrix factorization (PMF) model were used to apportion the sources of PAHs. The carcinogenic risk due to exposure to PAHs was estimated by the toxicity equivalent of BaP (BaPeq). The results showed that the average concentration of Σ₁₅PAHs was 68.3 ± 22.3 ng/m³, and the proportions of 3-ring, 4-ring, 5-ring, and 6-ring PAHs were 64.4%, 32.6%, 2.10%, and 0.89%, respectively. Among the six typical functional areas in Harbin, the Σ₁₅PAHs concentrations were 98.1 ± 76.7 ng/m³, 91.2 ± 76.2 ng/m³, 71.4 ± 75.6 ng/m³, 67.9 ± 65.6 ng/m³, 42.6 ± 34.7 ng/m³, and 38.5 ± 38.0 ng/m³ in the wastewater treatment plant, industrial zone, business district, residential area, school, and suburb, respectively. During the sampling period, the highest concentration of Σ₁₅PAHs was in winter. The improved NMF model and PMF model apportioned the PAHs into three sources including coal combustion, biomass burning, and vehicle exhaust. The contributions of coal combustion, biomass burning, and vehicle exhausts were 34.6 ± 3.22%, 48.6 ± 4.03%, and 16.8 ± 5.06%, respectively. Biomass burning was the largest contributor of Σ₁₅PAHs concentrations in winter and coal combustion contributed significantly to the concentrations in summer. The average ΣBaPeq concentration was 0.54 ± 0.23 ng/m³ during the sampling period, high concentrations occurred in the cold season and low levels presented in the warm period. Vehicle exhaust was the largest contributor to the ΣBaPeq concentration of PAHs in Harbin. Full article

(This article belongs to the Special Issue Atmospheric Pollutants: Source Apportionment and Its Impact on Public Health)

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21 pages, 3827 KiB

Open AccessEditor’s ChoiceArticle

Effects of PM₁₀ and Weather on Respiratory and Cardiovascular Diseases in the Ciuc Basin (Romanian Carpathians)

by Katalin Bodor, Miruna Mihaela Micheu, Ágnes Keresztesi, Marius-Victor Birsan, Ion-Andrei Nita, Zsolt Bodor, Sándor Petres, Attila Korodi and Róbert Szép

Atmosphere 2021, 12(2), 289; https://doi.org/10.3390/atmos12020289 - 23 Feb 2021

Cited by 14 | Viewed by 3386

Abstract

This study presents the PM₁₀ concentration, respiratory and cardiovascular disease hospital admissions evolution in the Ciuc basin for a period of 9 years (2008–2016), taking into consideration different meteorological conditions: boundary layer, lifting condensation level, temperature-humidity index, and wind chill equivalent chart [...] Read more.

This study presents the PM₁₀ concentration, respiratory and cardiovascular disease hospital admissions evolution in the Ciuc basin for a period of 9 years (2008–2016), taking into consideration different meteorological conditions: boundary layer, lifting condensation level, temperature-humidity index, and wind chill equivalent chart index. The PM₁₀ and hospital admissions evolution showed a very fluctuated hourly, weekly, monthly, yearly tendency. The PM₁₀ concentration in winter (34.72 μg/m³) was 82% higher than the multiannual average (19.00 μg/m³), and almost three times higher than in summer (11.71 μg/m³). During the winter, PM₁₀ concentration increased by an average of 9.36 μg/m³ due to the increased household heating. Climatological parameters have a demonstrable effect on the PM₁₀ concentration variation. Children, the elderly and men are more sensitive to air pollution, the calculated relative risk for men was (RR = 1.45), and for women (RR = 1.37), respectively. A moderate correlation (0.51) was found between PM₁₀ and pneumonia (P), while a relatively weak correlation (0.39) was demonstrated in the case of PM₁₀ and upper respiratory tract infections (URTI). Furthermore, except thermal humidity index (THI), strong negative correlations were observed between the multiannual monthly mean PM₁₀ and the meteorological data. The PM₁₀ followed a moderate negative correlation with the boundary layer (−0.61). In the case of URTI and P, the highest number of hospital admissions occurred with a 5 to 7-day lag, while the 10 μg/m³ PM₁₀ increase resulted in a 2.04% and 8.28% morbidity increase. For lung cancer (LC) and cardiovascular diseases (AMI, IHD, CCP), a maximum delay of 5–6 months was found. Three-month delay and an average growth of 1.51% was observed in the case of chronic obstructive pulmonary disease (COPD). Overall, these findings revealed that PM₁₀ was and it is responsible for one-third of the diseases. Full article

(This article belongs to the Section Air Quality and Health)

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9 pages, 603 KiB

Open AccessEditor’s ChoiceArticle

Association between Long-Term Exposure to PM_2.5 and Lung Imaging Phenotype in CODA Cohort

by Youlim Kim, So Hyeon Bak, Sung Ok Kwon, Ho Kim, Woo Jin Kim and Chang Youl Lee

Atmosphere 2021, 12(2), 282; https://doi.org/10.3390/atmos12020282 - 22 Feb 2021

Cited by 2 | Viewed by 2263

Abstract

Background and Aims: Ambient particulate matter (PM) is causing respiratory symptoms of individuals at all ages and reducing their lung functions. These individuals could develop chronic pulmonary disease. Recent studies have shown that short-term exposure to PM affects acute exacerbation of respiratory disease. [...] Read more.

Background and Aims: Ambient particulate matter (PM) is causing respiratory symptoms of individuals at all ages and reducing their lung functions. These individuals could develop chronic pulmonary disease. Recent studies have shown that short-term exposure to PM affects acute exacerbation of respiratory disease. However, evidence about the association between long-term exposure and progression of respiratory diseases remains insufficient. The purpose of this study was to examine the association between long-term exposure of air pollution (PM_2.5) and the effect on lung imaging phenotype in dust-exposed Korean adults living near cement factories. Methods: We conducted a cross-sectional analysis on the Chronic Obstructive Pulmonary Disease (COPD) in Dusty Areas (CODA) cohort, which was recruited from 2012 to 2014. Emphysema index and mean wall area were measured using an in-house software program developed by the Korean obstructive lung disease study group based on chest CT scan. A satellite-based model was used to estimate the long-term PM_2.5 concentration at each participant’s address. Results: Of 504 eligible participants, 400 participants were analyzed. Their mean age was 71.7 years. Most participants were men (N = 301, 75.3%). The emphysema index of the whole group was 6.63 ± 0.70, and the mean wall area was 68.8 ± 5.2. Image measurement and PM_2.5 concentration showed no significant difference in the whole group; however, in the group of subjects with normal lung function, there were significant associations between long-term PM_2.5 exposure and emphysema index measurement: 1-year (ß = 0.758, p = 0.021), 3-year (ß = 0.629, p = 0.038), and 5-year (ß = 0.544, p = 0.045). There was no significant association between long-term PM_2.5 exposure and mean wall area measurement: 1-year (ß = −0.389, p = 0.832), 3-year (ß = −3.677, p = 0.170), and 5-year (ß = −3.769, p = 0.124). Conclusions: This study suggests that long-term exposure of PM2.5 may affect the emphysematous change in patients with normal lung functions. Full article

(This article belongs to the Special Issue Impacts of Indoor Air Pollution on Cardiopulmonary System)

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22 pages, 3646 KiB

Open AccessEditor’s ChoiceArticle

Correction of Eddy Covariance Based Crop ET Considering the Heat Flux Source Area

by Stuart L. Joy and José L. Chávez

Atmosphere 2021, 12(2), 281; https://doi.org/10.3390/atmos12020281 - 21 Feb 2021

Cited by 2 | Viewed by 2770

Abstract

Eddy covariance (EC) systems are being used to measure sensible heat (H) and latent heat (LE) fluxes in order to determine crop water use or evapotranspiration (ET). The reliability of EC measurements depends on meeting certain meteorological assumptions; the most important of such [...] Read more.

Eddy covariance (EC) systems are being used to measure sensible heat (H) and latent heat (LE) fluxes in order to determine crop water use or evapotranspiration (ET). The reliability of EC measurements depends on meeting certain meteorological assumptions; the most important of such are horizontal homogeneity, stationarity, and non-advective conditions. Over heterogeneous surfaces, the spatial context of the measurement must be known in order to properly interpret the magnitude of the heat flux measurement results. Over the past decades, there has been a proliferation of ‘heat flux source area’ (i.e., footprint) modeling studies, but only a few have explored the accuracy of the models over heterogeneous agricultural land. A composite ET estimate was created by using the estimated footprint weights for an EC system in the upwind corner of four fields and separate ET estimates from each of these fields. Three analytical footprint models were evaluated by comparing the composite ET to the measured ET. All three models performed consistently well, with an average mean bias error (MBE) of about −0.03 mm h⁻¹ (−4.4%) and root mean square error (RMSE) of 0.09 mm h⁻¹ (10.9%). The same three footprint models were then used to adjust the EC-measured ET to account for the fraction of the footprint that extended beyond the field of interest. The effectiveness of the footprint adjustment was determined by comparing the adjusted ET estimates with the lysimetric ET measurements from within the same field. This correction decreased the absolute hourly ET MBE by 8%, and the RMSE by 1%. Full article

(This article belongs to the Special Issue Agricultural Microclimate and Irrigation Water Management)

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21 pages, 4799 KiB

Open AccessEditor’s ChoiceArticle

Environmental Partitioning, Spatial Distribution, and Transport of Atmospheric Mercury (Hg) Originating from a Site of Former Chlor-Alkali Plant

by Mert Guney, Aiganym Kumisbek, Zhanel Akimzhanova, Symbat Kismelyeva, Kamila Beisova, Almagul Zhakiyenova, Vassilis Inglezakis and Ferhat Karaca

Atmosphere 2021, 12(2), 275; https://doi.org/10.3390/atmos12020275 - 18 Feb 2021

Cited by 8 | Viewed by 2770

Abstract

Mercury (Hg) is one of the trace toxic and bioaccumulative global pollutants, and due to its long atmospheric lifetime, it presents a significant global challenge. The present study (1) utilizes total gaseous mercury (TGM) measurements made around a former Hg-cell chlor-alkali plant (CAP) [...] Read more.

Mercury (Hg) is one of the trace toxic and bioaccumulative global pollutants, and due to its long atmospheric lifetime, it presents a significant global challenge. The present study (1) utilizes total gaseous mercury (TGM) measurements made around a former Hg-cell chlor-alkali plant (CAP) located in Pavlodar, Kazakhstan, and predicts the spatial distribution of Hg over its premises and the nearby city. It then (2) estimates the environmental repartition of Hg deposited by the CAP using three fugacity models of varying complexity: Level I, QWASI, and HERMES. Finally, it (3) predicts long-range Hg transport via forward trajectory-based cluster analysis. The atmospheric Hg levels measured in Pavlodar and around Lake Balkyldak were elevated: in the range of 1–37 ng/m³ with an urban background level at 4.9 ng/m³. Specifically, concentrations up to 37 ng/m³ close to Lake Balkyldak and up to 22 ng/m³ nearby the city’s industrial zone (where the CAP was located) had been observed. Interpolation maps created using kriging also suggest these locations as the primary sources of atmospheric Hg in the city. The Level I fugacity model indicated that almost all of Hg is expected to end up in the atmosphere. The modeling results obtained using more complex QWASI and HERMES models showed that some significant quantity of Hg would still be associated with the sediments of Lake Balkyldak (a large wastewater discharge pond nearby the CAP). The forward trajectory-based cluster analysis method revealed the long-range atmospheric transportation routes and local, regional, and global impact zones. Furthermore, a source-receptor relationship using air transportation pathways to identify “areas of impact” was addressed. During both heating and non-heating seasons, the frequency-based analysis identified the distribution of Hg reaching the territories of Mongolia, northwest China, southwest Kazakhstan. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT-4) model forward trajectory analysis has confirmed similar patterns during heating and non-heating seasons, except with shorter impact distances during the non-heating period. Even though the CAP was closed more than 30 years ago and those past remediation efforts cleaned up the site, the residual Hg pollution seems significant and should be further investigated in different environmental media. Full article

(This article belongs to the Special Issue Sources, Spatiotemporal Variation and Potential Health Risk of Hazardous Air Pollutants)

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23 pages, 42884 KiB

Open AccessEditor’s ChoiceArticle

Overview of Aerosol Properties in the European Arctic in Spring 2019 Based on In Situ Measurements and Lidar Data

by Fieke Rader, Rita Traversi, Mirko Severi, Silvia Becagli, Kim-Janka Müller, Konstantina Nakoudi and Christoph Ritter

Atmosphere 2021, 12(2), 271; https://doi.org/10.3390/atmos12020271 - 17 Feb 2021

Cited by 10 | Viewed by 3140

Abstract

In this work, we analysed aerosol measurements from lidar and PM

_{10}

samples around the European Arctic site of Ny-Ålesund during late winter–early spring 2019. Lidar observations above 700 m revealed time-independent values for the aerosol backscatter coefficient (β

β

), colour [...] Read more.

In this work, we analysed aerosol measurements from lidar and PM

_{10}

samples around the European Arctic site of Ny-Ålesund during late winter–early spring 2019. Lidar observations above 700 m revealed time-independent values for the aerosol backscatter coefficient (β

β

), colour ratio (CR), linear particle depolarisation ratio (δ

δ

) and lidar ratio (LR) from January to April. In contrast to previous years, in 2019 the early springtime backscatter increase in the troposphere, linked to Arctic haze, was not observed. In situ nss-sulphate (nss-SO

_{4}^{2 -}

) concentration was measured both at a coastal (Gruvebadet) and a mountain (Zeppelin) station, a few kilometres apart. As we employed different measurement techniques at sites embedded in complex orography, we investigated their agreement. From the lidar perspective, the aerosol load (indicated by β

β

) above 700 m changed by less than a factor of 3.5. On the contrary, the daily nss-SO

_{4}^{2 -}

concentration erratically changed by a factor of 25 (from 0.1 to 2.5 ng m

^{- 3}

) both at Gruvebadet and Zeppelin station, with the latter mostly lying above the boundary layer. Moreover, daily nss-SO

_{4}^{2 -}

concentration was remarkably variable (correlation about 0.7 between the sites), despite its long-range origin. However, on a seasonal average basis the in situ sites agreed very well. Therefore, it can be argued that nss-SO

_{4}^{2 -}

advection mainly takes place in the lowest free troposphere, while under complex orography it is mixed downwards by local boundary layer processes. Our study suggests that at Arctic sites with complex orography ground-based aerosol properties show higher temporal variability compared to the free troposphere. This implies that the comparison between remote sensing and in situ observations might be more reasonable on longer time scales, i.e., monthly and seasonal basis even for nearby sites. Full article

(This article belongs to the Special Issue Chemical-Physical and Optical Properties of the Aerosol in Europe and the Arctic)

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20 pages, 4929 KiB

Open AccessEditor’s ChoiceArticle

Regional Scale Impact of the COVID-19 Lockdown on Air Quality: Gaseous Pollutants in the Po Valley, Northern Italy

by Giovanni Lonati and Federico Riva

Atmosphere 2021, 12(2), 264; https://doi.org/10.3390/atmos12020264 - 17 Feb 2021

Cited by 26 | Viewed by 4485

Abstract

The impact of the reduced atmospheric emissions due to the COVID-19 lockdown on ambient air quality in the Po Valley of Northern Italy was assessed for gaseous pollutants (NO₂, benzene, ammonia) based on data collected at the monitoring stations distributed all [...] Read more.

The impact of the reduced atmospheric emissions due to the COVID-19 lockdown on ambient air quality in the Po Valley of Northern Italy was assessed for gaseous pollutants (NO₂, benzene, ammonia) based on data collected at the monitoring stations distributed all over the area. Concentration data for each month of the first semester of 2020 were compared with those of the previous six years, on monthly, daily, and hourly bases, so that pre, during, and post-lockdown conditions of air quality could be separately analyzed. The results show that, as in many other areas worldwide, the Po Valley experienced better air quality during 2020 spring months for NO₂ and benzene. In agreement with the reductions of nitrogen oxides and benzene emissions from road traffic, estimated to be −35% compared to the regional average, the monthly mean concentration levels for 2020 showed reductions in the −40% to −35% range compared with the previous years, but with higher reductions, close to −50%, at high-volume-traffic sites in urban areas. Conversely, NH₃ ambient concentration levels, almost entirely due the emissions of the agricultural sector, did not show any relevant change, even at high-volume-traffic sites in urban areas. These results point out the important role of traffic emissions in NO₂ and benzene ambient levels in the Po Valley, and confirm that this region is a rather homogeneous air basin with urban area hot-spots, the contributions of which add up to a relatively high regional background concentration level. Additionally, the relatively slow response of the air quality levels to the sudden decrease of the emissions due to the lockdown shows that this region is characterized by a weak exchange of the air masses that favors both the build-up of atmospheric pollutants and the development of secondary formation processes. Thus, air quality control strategies should aim for structural interventions intended to reduce traffic emissions at the regional scale and not only in the largest urban areas. Full article

(This article belongs to the Special Issue Coronavirus Pandemic Shutdown Effects on Urban Air Quality)

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12 pages, 2856 KiB

Open AccessEditor’s ChoiceArticle

Concentrations and Sources of Atmospheric PM, Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Kanazawa, Japan

by Kazuichi Hayakawa, Ning Tang, Wanli Xing, Pham Kim Oanh, Akinori Hara and Hiroyuki Nakamura

Atmosphere 2021, 12(2), 256; https://doi.org/10.3390/atmos12020256 - 15 Feb 2021

Cited by 13 | Viewed by 3135

Abstract

PM_2.5 (fine particles with diameters 2.5 micrometers and smaller) and PM_>2.5 were separately collected in Kanazawa, Japan in every season, from the spring of 2017 to the winter of 2018, and nine polycyclic aromatic hydrocarbons (PAHs) and six nitropolycyclic aromatic hydrocarbons [...] Read more.

PM_2.5 (fine particles with diameters 2.5 micrometers and smaller) and PM_>2.5 were separately collected in Kanazawa, Japan in every season, from the spring of 2017 to the winter of 2018, and nine polycyclic aromatic hydrocarbons (PAHs) and six nitropolycyclic aromatic hydrocarbons (NPAHs) were respectively determined using high-performance liquid chromatography (HPLC) with fluorescence and chemiluminescence detections. The atmospheric concentrations of both the PAHs and NPAHs showed seasonal changes (highest in the winter and lowest in the summer), which differed from the variations in the total suspended particulate matter (TSP) and PM_2.5 amounts (which were highest in the spring). The contributions of major sources to the combustion-derived particulate (P_c) in the PM_2.5 were calculated using the 1-nitropyrene-pyrene (NP) method, using pyrene and 1-nitropyrene as the representative markers of PAHs and NPAHs, respectively. The annual average concentration of P_c accounted for only 2.1% of PM_2.5, but showed the same seasonal variation as PAHs. The sources of P_c were vehicles (31%) and coal heating facilities/industries (69%). A backward trajectory analysis showed that the vehicle-derived P_c was mainly from Kanazawa and its surroundings, and that coal heating facilities/industry-derived P_c was transported from city areas in central and northern China in the winter, and during the Asian dust event in the spring. These results show that large amounts of PAHs were transported over a long range from China during the winter. Even in the spring, after the coal heating season was over in China, PAHs were still transported to Japan after Asian dust storms passed through Chinese city areas. By contrast, the main contributors of NPAHs were vehicles in Kanazawa and its surroundings. The recent P_c concentrations were much lower than those in 1999. This decrease was mostly attributed to the decrease in the contribution of vehicle emissions. Thus, the changes in the atmospheric concentrations of P_c, PAHs and NPAHs in Kanazawa were strongly affected not only by the local emissions but also by long-range transport from China. Full article

(This article belongs to the Special Issue Air Pollution in Japan)

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13 pages, 7848 KiB

Open AccessEditor’s ChoiceArticle

Impact of COVID-19-Related Traffic Slowdown on Urban Heat Characteristics

by Bernardo Teufel, Laxmi Sushama, Vincent Poitras, Tarek Dukhan, Stéphane Bélair, Luis Miranda-Moreno, Lijun Sun, Agus P. Sasmito and Girma Bitsuamlak

Atmosphere 2021, 12(2), 243; https://doi.org/10.3390/atmos12020243 - 11 Feb 2021

Cited by 29 | Viewed by 5628

Abstract

Governments around the world have implemented measures to slow down the spread of COVID-19, resulting in a substantial decrease in the usage of motorized transportation. The ensuing decrease in the emission of traffic-related heat and pollutants is expected to impact the environment through [...] Read more.

Governments around the world have implemented measures to slow down the spread of COVID-19, resulting in a substantial decrease in the usage of motorized transportation. The ensuing decrease in the emission of traffic-related heat and pollutants is expected to impact the environment through various pathways, especially near urban areas, where there is a higher concentration of traffic. In this study, we perform high-resolution urban climate simulations to assess the direct impact of the decrease in traffic-related heat emissions due to COVID-19 on urban temperature characteristics. One simulation spans the January–May 2020 period; two additional simulations spanning the April 2019–May 2020 period, with normal and reduced traffic, are used to assess the impacts throughout the year. These simulations are performed for the city of Montreal, the second largest urban centre in Canada. The mechanisms and main findings of this study are likely to be applicable to most large urban centres around the globe. The results show that an 80% reduction in traffic results in a decrease of up to 1 °C in the near-surface temperature for regions with heavy traffic. The magnitude of the temperature decrease varies substantially with the diurnal traffic cycle and also from day to day, being greatest when the near-surface wind speeds are low and there is a temperature inversion in the surface layer. This reduction in near-surface temperature is reflected by an up to 20% reduction in hot hours (when temperature exceeds 30 °C) during the warm season, thus reducing heat stress for vulnerable populations. No substantial changes occur outside of traffic corridors, indicating that potential reductions in traffic would need to be supplemented by additional measures to reduce urban temperatures and associated heat stress, especially in a warming climate, to ensure human health and well-being. Full article

(This article belongs to the Section Biometeorology and Bioclimatology)

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27 pages, 11425 KiB

Open AccessEditor’s ChoiceArticle

Characterization of Aerosol Sources and Optical Properties in Siberia Using Airborne and Spaceborne Observations

by Antonin Zabukovec, Gerard Ancellet, Iwan E. Penner, Mikhail Arshinov, Valery Kozlov, Jacques Pelon, Jean-Daniel Paris, Grigory Kokhanenko, Yuri S. Balin, Dimitry Chernov and Boris D. Belan

Atmosphere 2021, 12(2), 244; https://doi.org/10.3390/atmos12020244 - 11 Feb 2021

Cited by 6 | Viewed by 2424

Abstract

Airborne backscatter lidar at 532 nm and in-situ measurements of black carbon (BC), carbon monoxide excess above background (ΔCO), and aerosol size distribution were carried out over Siberia in July 2013 and June 2017 in order to sample several kinds of aerosol sources. [...] Read more.

Airborne backscatter lidar at 532 nm and in-situ measurements of black carbon (BC), carbon monoxide excess above background (ΔCO), and aerosol size distribution were carried out over Siberia in July 2013 and June 2017 in order to sample several kinds of aerosol sources. Aerosol types are derived using the Lagrangian FLEXible PARTicle dispersion model (FLEXPART) simulations and satellite observations. Six aerosol types could be identified in this work: (i) dusty aerosol mixture, (ii) Ob valley gas flaring emission, (iii) fresh forest fire, (iv) aged forest fire, (v) urban emissions over the Tomsk/Novosibirsk region (vi) long range transport of Northern China urban emission. The altitude range of aerosol layers is discussed for each aerosol type, showing transport above the boundary layer for long range transport of Northern China emissions or fresh forest fire. Comparisons of aerosol optical properties, BC and ΔCO are made between aged and fresh plumes for both the urban and forest fire emissions. An increase of aerosol optical depth at 532 nm (AOD

_{532}

), aerosol particle size and ΔCO is found for aged forest fire plumes. Similar results are obtained when comparing the aged urban plume from Northern China with fresh urban emissions from Siberian cities. A flight above gas flaring emissions corresponds to the largest AOD

_{532}

and provides a possible range of 50–60 sr for the lidar ratio of these aerosol plumes often encountered in Siberia. Black carbon concentrations are relatively higher for the flaring plume (0.4–0.5 μ

μ g . m^{- 3}

) than for the urban plume (0.2 μ

μ g . m^{- 3}

). The largest BC concentrations are found for the fresh forest fire plume. The aerosol type identification and AOD

_{532}

provided by CALIOP Version 4.2 data products in air masses with similar origin generally agree with the results obtained from our detailed analysis of the aerosol plume origins. Full article

(This article belongs to the Special Issue Tropospheric Aerosols: Observation, Modeling, and Assimilation)

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17 pages, 28804 KiB

Open AccessEditor’s ChoiceArticle

Nocturnal Boundary Layer Erosion Analysis in the Amazon Using Large-Eddy Simulation during GoAmazon Project 2014/5

by Rayonil Carneiro, Gilberto Fisch, Theomar Neves, Rosa Santos, Carlos Santos and Camilla Borges

Atmosphere 2021, 12(2), 240; https://doi.org/10.3390/atmos12020240 - 10 Feb 2021

Cited by 6 | Viewed by 3145

Abstract

This study investigated the erosion of the nocturnal boundary layer (NBL) over the central Amazon using a high-resolution model of large-eddy simulation (LES) named PArallel Les Model (PALM) and observational data from Green Ocean Amazon (GoAmazon) project 2014/5. This data set was collected [...] Read more.

This study investigated the erosion of the nocturnal boundary layer (NBL) over the central Amazon using a high-resolution model of large-eddy simulation (LES) named PArallel Les Model (PALM) and observational data from Green Ocean Amazon (GoAmazon) project 2014/5. This data set was collected during four intense observation periods (IOPs) in the dry and rainy seasons in the years 2014 (considered a typical year) and 2015, during which an El Niño–Southern Oscillation (ENSO) event predominated and provoked an intense dry season. The outputs from the PALM simulations represented reasonably well the NBL erosion, and the results showed that it has different characteristics between the seasons. During the rainy season, the IOPs exhibited slow surface heating and less intense convection, which resulted in a longer erosion period, typically about 3 h after sunrise (that occurs at 06:00 local time). In contrast, dry IOPs showed more intensive surface warming with stronger convection, resulting in faster NBL erosion, about 2 h after sunrise. A conceptual model was derived to investigate the complete erosion during sunrise hours when there is a very shallow mixed layer formed close to the surface and a stable layer above. The kinematic heat flux for heating this layer during the erosion period showed that for the rainy season, the energy emitted from the surface and the entrainment was not enough to fully heat the NBL layer and erode it. Approximately 30% of additional energy was used in the system, which could come from the release of energy from biomass. The dry period of 2014 showed stronger heating, but it was also not enough, requiring approximately 6% of additional energy. However, for the 2015 dry period, which was under the influence of the ENSO event, it was shown that the released surface fluxes were sufficient to fully heat the layer. The erosion time of the NBL probably influenced the development of the convective boundary layer (CBL), wherein greater vertical development was observed in the dry season IOPs (~1500 m), while the rainy season IOPs had a shallower layer (~1200 m). Full article

(This article belongs to the Special Issue The Stable Boundary Layer: Observations and Modeling)

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14 pages, 6267 KiB

Open AccessEditor’s ChoiceArticle

Analyzing the Probability of Acquiring Cloud-Free Imagery in China with AVHRR Cloud Mask Data

by Yingjie Wu, Shibo Fang, Yi Xu, Lei Wang, Xuan Li, Zhifang Pei and Dong Wu

Atmosphere 2021, 12(2), 214; https://doi.org/10.3390/atmos12020214 - 4 Feb 2021

Cited by 3 | Viewed by 2067

Abstract

Optical remote sensing data are used widely in many fields (such as agriculture, resource management and the environment), especially for the vast territory of China; however, the application of these data is usually limited by clouds. Although it is valuable to analyze the [...] Read more.

Optical remote sensing data are used widely in many fields (such as agriculture, resource management and the environment), especially for the vast territory of China; however, the application of these data is usually limited by clouds. Although it is valuable to analyze the probability of acquiring cloud-free imagery (PACI), PACI using different sensors at the pixel level across China has not been reported. In this study, the PACI of China was calculated with daily Advanced Very High Resolution Radiometer (AVHRR) cloud mask data from 1990 to 2019. The results showed that (1) PACI varies dramatically in different regions and months in China. The value was larger in autumn and winter, and the largest figure reached 49.55% in October in Inner Mongolia (NM). In contrast, relatively small values occurred in summer, and the minimum value (5.26%) occurred in June in South China (SC). (2) As the climate changes, the PACI has increased significantly throughout the country and most regions, especially in North China (NC), with a growth rate of 1.9% per decade. The results can be used as a reference for selecting appropriate optical sensors and observation times in areas of interest. Full article

(This article belongs to the Section Atmospheric Techniques, Instruments, and Modeling)

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16 pages, 27007 KiB

Open AccessEditor’s ChoiceArticle

The ESTE Decision Support System for Nuclear and Radiological Emergencies: Atmospheric Dispersion Models

by Ľudovít Lipták, Eva Fojcíková, Monika Krpelanová, Viera Fabová and Peter Čarný

Atmosphere 2021, 12(2), 204; https://doi.org/10.3390/atmos12020204 - 3 Feb 2021

Cited by 3 | Viewed by 2436

Abstract

The ESTE system is running in nuclear crisis centers at various levels of emergency preparedness and response in Slovakia, the Czech Republic, Austria, Bulgaria, and Iran (at the Bushehr Nuclear Power Plant, monitored by the International Atomic Energy Agency (IAEA)). ESTE is a [...] Read more.

The ESTE system is running in nuclear crisis centers at various levels of emergency preparedness and response in Slovakia, the Czech Republic, Austria, Bulgaria, and Iran (at the Bushehr Nuclear Power Plant, monitored by the International Atomic Energy Agency (IAEA)). ESTE is a decision-support system that runs 24/7 and serves the crisis staff to propose actions to protect inhabitants against radiation in case of a nuclear accident. ESTE is also applicable as a decision-support system in case of a malicious act with a radioactive dispersal device in an urban or industrial environment. The dispersion models implemented in ESTE are the Lagrangian particle model (LPM) and the Puff trajectory model (PTM). We describe model approaches as implemented in ESTE. The PTM is applied in ESTE for the dispersion calculation near the point of release, up to 100 km from the point of a nuclear accident. The LPM for general atmospheric transport is applied for short-range, meso-scale and large-scale dispersion, up to dispersion on the global scale. Additionally, a specific micro-scale implementation of the LPM is applied for urban scale dispersion modeling. The dispersion models of ESTE are joined with radiological-consequences models to calculate a complete spectrum of radiological parameters—effective doses, committed doses, and dose rates by various irradiation pathways and by various radionuclides. Finally, radiation protective measures, like sheltering, iodine prophylaxis, or evacuation, evaluated on the base of predicted radiological impacts, are proposed. The dispersion and radiological models of the state-of-the-art ESTE systems are described. The results of specific analyses, like the number of particles applied, the initial spatial distribution of the source, and the height of the bottom reference layer, are presented and discussed. Full article

(This article belongs to the Special Issue Atmospheric Dispersion Modeling of Hazardous Releases from Accident, Terrorist Attack or Natural Disaster)

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19 pages, 2729 KiB

Open AccessEditor’s ChoiceArticle

Quantification of Non-Exhaust Particulate Matter Traffic Emissions and the Impact of COVID-19 Lockdown at London Marylebone Road

by William Hicks, Sean Beevers, Anja H. Tremper, Gregor Stewart, Max Priestman, Frank J. Kelly, Mathias Lanoisellé, Dave Lowry and David C. Green

Atmosphere 2021, 12(2), 190; https://doi.org/10.3390/atmos12020190 - 31 Jan 2021

Cited by 44 | Viewed by 8124

Abstract

This research quantifies current sources of non-exhaust particulate matter traffic emissions in London using simultaneous, highly time-resolved, atmospheric particulate matter mass and chemical composition measurements. The measurement campaign ran at Marylebone Road (roadside) and Honor Oak Park (background) urban monitoring sites over a [...] Read more.

This research quantifies current sources of non-exhaust particulate matter traffic emissions in London using simultaneous, highly time-resolved, atmospheric particulate matter mass and chemical composition measurements. The measurement campaign ran at Marylebone Road (roadside) and Honor Oak Park (background) urban monitoring sites over a 12-month period between 1 September 2019 and 31 August 2020. The measurement data were used to determine the traffic increment (roadside–background) and covered a range of meteorological conditions, seasons, and driving styles, as well as the influence of the COVID-19 “lockdown” on non-exhaust concentrations. Non-exhaust particulate matter (PM)₁₀ concentrations were calculated using chemical tracer scaling factors for brake wear (barium), tyre wear (zinc), and resuspension (silicon) and as average vehicle fleet non-exhaust emission factors, using a CO₂ “dilution approach”. The effect of lockdown, which saw a 32% reduction in traffic volume and a 15% increase in average speed on Marylebone Road, resulted in lower PM₁₀ and PM_2.5 traffic increments and brake wear concentrations but similar tyre and resuspension concentrations, confirming that factors that determine non-exhaust emissions are complex. Brake wear was found to be the highest average non-exhaust emission source. In addition, results indicate that non-exhaust emission factors were dependent upon speed and road surface wetness conditions. Further statistical analysis incorporating a wider variability in vehicle mix, speeds, and meteorological conditions, as well as advanced source apportionment of the PM measurement data, were undertaken to enhance our understanding of these important vehicle sources. Full article

(This article belongs to the Special Issue Elemental Composition, Sources and Health Impacts of Aerosols in Large Urban Areas)

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10 pages, 1686 KiB

Open AccessEditor’s ChoiceArticle

Distinct Regimes of O₃ Response to COVID-19 Lockdown in China

by Shanshan Liu, Cheng Liu, Qihou Hu, Wenjing Su, Xian Yang, Jinan Lin, Chengxin Zhang, Chengzhi Xing, Xiangguang Ji, Wei Tan, Haoran Liu and Meng Gao

Atmosphere 2021, 12(2), 184; https://doi.org/10.3390/atmos12020184 - 30 Jan 2021

Cited by 11 | Viewed by 3959

Abstract

Restrictions on human activities remarkably reduced emissions of air pollutants in China during the COVID-19 lockdown periods. However, distinct responses of O₃ concentrations were observed across China. In the Beijing–Tianjin–Hebei (BTH) and Yangtze River Delta (YRD) regions, O₃ concentrations were enhanced [...] Read more.

Restrictions on human activities remarkably reduced emissions of air pollutants in China during the COVID-19 lockdown periods. However, distinct responses of O₃ concentrations were observed across China. In the Beijing–Tianjin–Hebei (BTH) and Yangtze River Delta (YRD) regions, O₃ concentrations were enhanced by 90.21 and 71.79% from pre-lockdown to lockdown periods in 2020, significantly greater than the equivalent concentrations for the same periods over 2015–2019 (69.99 and 43.62%, p < 0.001). In contrast, a decline was detected (−1.1%) in the Pearl River Delta (PRD) region. To better understand the underlying causes for these inconsistent responses across China, we adopted the least absolute shrinkage and selection operator (Lasso) and ordinary linear squares (OLS) methods in this study. Statistical analysis indicated that a sharp decline in nitrogen dioxide (NO₂) was the major driver of enhanced O₃ in the BTH region as it is a NO_x-saturated region. In the YRD region, season-shift induced changes in the temperature/shortwave radiative flux, while lockdown induced declines in NO₂, attributable to the rise in O₃. In the PRD region, the slight drop in O₃ is attributed to the decreased intensity of radiation. The distinct regimes of the O₃ response to the COVID-19 lockdown in China offer important insights into different O₃ control strategies across China. Full article

(This article belongs to the Special Issue New Developments in Ozone Pollution across Local, Regional, and Global Scales)

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28 pages, 16663 KiB

Open AccessEditor’s ChoiceArticle

High-Resolution Modelling of Thermal Exposure during a Hot Spell: A Case Study Using PALM-4U in Prague, Czech Republic

by Jan Geletič, Michal Lehnert, Pavel Krč, Jaroslav Resler and Eric Scott Krayenhoff

Atmosphere 2021, 12(2), 175; https://doi.org/10.3390/atmos12020175 - 29 Jan 2021

Cited by 29 | Viewed by 4393

Abstract

The modelling of thermal exposure in outdoor urban environments is a highly topical challenge in modern climate research. This paper presents the results derived from a new micrometeorological model that employs an integrated biometeorology module to model Universal Thermal Climate Index (UTCI). This [...] Read more.

The modelling of thermal exposure in outdoor urban environments is a highly topical challenge in modern climate research. This paper presents the results derived from a new micrometeorological model that employs an integrated biometeorology module to model Universal Thermal Climate Index (UTCI). This is PALM-4U, which includes an integrated human body-shape parameterization, deployed herein for a pilot domain in Prague, Czech Republic. The results highlight the key role of radiation in the spatiotemporal variability of thermal exposure in moderate-climate urban areas during summer days in terms of the way in which this directly affects thermal comfort through radiant temperature and indirectly through the complexity of turbulence in street canyons. The model simulations suggest that the highest thermal exposure may be expected within street canyons near the irradiated north sides of east–west streets and near streets oriented north–south. Heat exposure in streets increases in proximity to buildings with reflective paints. The lowest heat exposure during the day may be anticipated in tree-shaded courtyards. The cooling effect of trees may range from 4 °C to 9 °C in UTCI, and the cooling effect of grass in comparison with artificial paved surfaces in open public places may be from 2 °C to 5 °C UTCI. In general terms, this study illustrates that the PALM modelling system provides a new perspective on the spatiotemporal differentiation of thermal exposure at the pedestrian level; it may therefore contribute to more climate-sensitive urban planning. Full article

(This article belongs to the Special Issue Outdoor Thermal Comfort in Cities: Assessing and Developing Green, Blue and Grey Solutions for Healthy and Sustainable Urban Future)

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19 pages, 11023 KiB

Open AccessEditor’s ChoiceArticle

Observations and Simulations of Meteorological Conditions over Arctic Thick Sea Ice in Late Winter during the Transarktika 2019 Expedition

by Günther Heinemann, Sascha Willmes, Lukas Schefczyk, Alexander Makshtas, Vasilii Kustov and Irina Makhotina

Atmosphere 2021, 12(2), 174; https://doi.org/10.3390/atmos12020174 - 28 Jan 2021

Cited by 12 | Viewed by 2635

Abstract

The parameterization of ocean/sea-ice/atmosphere interaction processes is a challenge for regional climate models (RCMs) of the Arctic, particularly for wintertime conditions, when small fractions of thin ice or open water cause strong modifications of the boundary layer. Thus, the treatment of sea ice [...] Read more.

The parameterization of ocean/sea-ice/atmosphere interaction processes is a challenge for regional climate models (RCMs) of the Arctic, particularly for wintertime conditions, when small fractions of thin ice or open water cause strong modifications of the boundary layer. Thus, the treatment of sea ice and sub-grid flux parameterizations in RCMs is of crucial importance. However, verification data sets over sea ice for wintertime conditions are rare. In the present paper, data of the ship-based experiment Transarktika 2019 during the end of the Arctic winter for thick one-year ice conditions are presented. The data are used for the verification of the regional climate model COSMO-CLM (CCLM). In addition, Moderate Resolution Imaging Spectroradiometer (MODIS) data are used for the comparison of ice surface temperature (IST) simulations of the CCLM sea ice model. CCLM is used in a forecast mode (nested in ERA5) for the Norwegian and Barents Seas with 5 km resolution and is run with different configurations of the sea ice model and sub-grid flux parameterizations. The use of a new set of parameterizations yields improved results for the comparisons with in-situ data. Comparisons with MODIS IST allow for a verification over large areas and show also a good performance of CCLM. The comparison with twice-daily radiosonde ascents during Transarktika 2019, hourly microwave water vapor measurements of first 5 km in the atmosphere and hourly temperature profiler data show a very good representation of the temperature, humidity and wind structure of the whole troposphere for CCLM. Full article

(This article belongs to the Section Meteorology)

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14 pages, 2479 KiB

Open AccessEditor’s ChoiceArticle

Spatiotemporal Estimation of the Olive and Vine Cultivations’ Growing Degree Days in the Balkans Region

by Ioannis Charalampopoulos, Iliana Polychroni, Emmanouil Psomiadis and Panagiotis Nastos

Atmosphere 2021, 12(2), 148; https://doi.org/10.3390/atmos12020148 - 24 Jan 2021

Cited by 17 | Viewed by 2923

Abstract

Olive and vine cultivations are two of the most important crops in Europe, yielding high quality and value food products. The climate change over the Balkans may elevate the agroecological pressure for the established crops and shift their cultivations areas. One of the [...] Read more.

Olive and vine cultivations are two of the most important crops in Europe, yielding high quality and value food products. The climate change over the Balkans may elevate the agroecological pressure for the established crops and shift their cultivations areas. One of the widely-used agroclimatic indices is the growing degree days (GDD) which accumulates the necessary thermal units for the selected crops. Despite the advances on the agroclimatic research, there are few available methods for spatiotemporal estimation of this useful index. So, this research is focused on the construction of simple and reliable equations for the calculation and projection of olive and vine cultivations’ GDD over the Balkans. The models’ input parameters are the time, the altitude, the distance from the seashore, and the latitude. Its assembly is made by the extracted spatial data, combined with the Agri4Cast dataset for the period of 1980 to 2018 incorporating the regional climate change trend. The results indicate that the most influential parameter is the time, followed by the latitude, for both cultivations. According to the projections, as quantified by GDD, a vast sprawl of olive and vine cultivation areas will have been formed to the northern parts of the studied area. To be more precise, the viticulture could expand spatially by 28.8% (of the Balkans area) by 2040, and by 15.1% to 2060, when the olive cultivations’ area could sprawl 23.9% by 2040 and 20.3% by 2060. Full article

(This article belongs to the Section Biometeorology and Bioclimatology)

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14 pages, 7904 KiB

Open AccessEditor’s ChoiceArticle

Different Relationships between Arctic Oscillation and Ozone in the Stratosphere over the Arctic in January and February

by Meichen Liu and Dingzhu Hu

Atmosphere 2021, 12(2), 129; https://doi.org/10.3390/atmos12020129 - 20 Jan 2021

Cited by 6 | Viewed by 2437

Abstract

We compare the relationship between the Arctic Oscillation (AO) and ozone concentration in the lower stratosphere over the Arctic during 1980–1994 (P1) and 2007–2019 (P2) in January and February using reanalysis datasets. The out-of-phase relationship between the AO and ozone in the lower [...] Read more.

We compare the relationship between the Arctic Oscillation (AO) and ozone concentration in the lower stratosphere over the Arctic during 1980–1994 (P1) and 2007–2019 (P2) in January and February using reanalysis datasets. The out-of-phase relationship between the AO and ozone in the lower stratosphere is significant in January during P1 and February during P2, but it is insignificant in January during P2 and February during P1. The variable links between the AO and ozone in the lower stratosphere over the Arctic in January and February are not caused by changes in the spatial pattern of AO but are related to the anomalies in the planetary wave propagation between the troposphere and stratosphere. The upward propagation of the planetary wave in the stratosphere related to the positive phase of AO significantly weakens in January during P1 and in February during P2, which may be related to negative buoyancy frequency anomalies over the Arctic. When the AO is in the positive phase, the anomalies of planetary wave further contribute to the negative ozone anomalies via weakening the Brewer–Dobson circulation and decreasing the temperature in the lower stratosphere over the Arctic in January during P1 and in February during P2. Full article

(This article belongs to the Special Issue Ozone and Stratospheric Dynamics)

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20 pages, 12359 KiB

Open AccessEditor’s ChoiceArticle

Quantifying the Impact of the Covid-19 Lockdown Measures on Nitrogen Dioxide Levels throughout Europe

by Sverre Solberg, Sam-Erik Walker, Philipp Schneider and Cristina Guerreiro

Atmosphere 2021, 12(2), 131; https://doi.org/10.3390/atmos12020131 - 20 Jan 2021

Cited by 33 | Viewed by 4291

Abstract

In this paper, the effect of the lockdown measures on nitrogen dioxide (NO₂) in Europe is analysed by a statistical model approach based on a generalised additive model (GAM). The GAM is designed to find relationships between various meteorological parameters and [...] Read more.

In this paper, the effect of the lockdown measures on nitrogen dioxide (NO₂) in Europe is analysed by a statistical model approach based on a generalised additive model (GAM). The GAM is designed to find relationships between various meteorological parameters and temporal metrics (day of week, season, etc.) on the one hand and the level of pollutants on the other. The model is first trained on measurement data from almost 2000 monitoring stations during 2015–2019 and then applied to the same stations in 2020, providing predictions of expected concentrations in the absence of a lockdown. The difference between the modelled levels and the actual measurements from 2020 is used to calculate the impact of the lockdown measures adjusted for confounding effects, such as meteorology and temporal trends. The study is focused on April 2020, the month with the strongest reductions in NO₂, as well as on the gradual recovery until the end of July. Significant differences between the countries are identified, with the largest NO₂ reductions in Spain, France, Italy, Great Britain and Portugal and the smallest in eastern countries (Poland and Hungary). The model is found to perform best for urban and suburban sites. A comparison between the found relative changes in urban surface NO₂ data during the lockdown and the corresponding changes in tropospheric vertical NO₂ column density as observed by the TROPOMI instrument on Sentinel-5P revealed good agreement despite substantial differences in the observing method. Full article

(This article belongs to the Section Air Quality)

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10 pages, 2394 KiB

Open AccessEditor’s ChoiceArticle

First High-Frequency Underway Observation of DMS Distribution in the Southern Ocean during Austral Autumn

by Intae Kim, Miming Zhang, Kitae Kim and Keyhong Park

Atmosphere 2021, 12(1), 122; https://doi.org/10.3390/atmos12010122 - 16 Jan 2021

Cited by 5 | Viewed by 2789

Abstract

We investigate the distribution of dimethyl sulfide (DMS) in the Southern Ocean’s (50° W to 170° W) surface water, including the Antarctic Peninsula and the marginal sea ice zone (MIZ) in the Ross and Amundsen Seas. This is the first high-frequency observation conducted [...] Read more.

We investigate the distribution of dimethyl sulfide (DMS) in the Southern Ocean’s (50° W to 170° W) surface water, including the Antarctic Peninsula and the marginal sea ice zone (MIZ) in the Ross and Amundsen Seas. This is the first high-frequency observation conducted in the austral autumn (in April) in the Southern Ocean. The mean DMS concentration was 2.7 ± 2.5 nM (1 σ) for the entire study area. Noticeably enhanced DMS (5 to 28 nM) concentrations were observed in the MIZ around the Ross and Amundsen Seas and the coastal regions in the Antarctic Peninsula; this could be attributed to biological production of local ice algae, which appears to be supplied with nutrients from glacial or sea ice melt water. These observed DMS inventories were significantly higher (an order of magnitude) than current climatological DMS inventories. The local DMS sources being transported outward from the polynyas, where strong bloom occurs during summer, could result in larger discrepancies between observed DMS and climatological DMS in the MIZ area (in the Amundsen Sea). Overall, this study is the first to highlight the significance of the underestimation of current DMS fluxes in the austral autumn, which consequently results in significant errors in the climate models. Full article

(This article belongs to the Special Issue Sources, Transport, and Sinks of Biogenic Sulfur in the Atmosphere)

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14 pages, 1009 KiB

Open AccessEditor’s ChoiceArticle

Circadian Deregulation as Possible New Player in Pollution-Induced Tissue Damage

by Mascia Benedusi, Elena Frigato, Cristiano Bertolucci and Giuseppe Valacchi

Atmosphere 2021, 12(1), 116; https://doi.org/10.3390/atmos12010116 - 15 Jan 2021

Cited by 6 | Viewed by 2792

Abstract

Circadian rhythms are 24-h oscillations driven by a hypothalamic master oscillator that entrains peripheral clocks in almost all cells, tissues and organs. Circadian misalignment, triggered by industrialization and modern lifestyles, has been linked to several pathological conditions, with possible impairment of the quality [...] Read more.

Circadian rhythms are 24-h oscillations driven by a hypothalamic master oscillator that entrains peripheral clocks in almost all cells, tissues and organs. Circadian misalignment, triggered by industrialization and modern lifestyles, has been linked to several pathological conditions, with possible impairment of the quality or even the very existence of life. Living organisms are continuously exposed to air pollutants, and among them, ozone or particulate matters (PMs) are considered to be among the most toxic to human health. In particular, exposure to environmental stressors may result not only in pulmonary and cardiovascular diseases, but, as it has been demonstrated in the last two decades, the skin can also be affected by pollution. In this context, we hypothesize that chronodistruption can exacerbate cell vulnerability to exogenous damaging agents, and we suggest a possible common mechanism of action in deregulation of the homeostasis of the pulmonary, cardiovascular and cutaneous tissues and in its involvement in the development of pathological conditions. Full article

(This article belongs to the Special Issue Contributions of Aerosol Sources to Health Impacts)

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21 pages, 4238 KiB

Open AccessEditor’s ChoiceArticle

Public Health Considerations for PM₁₀ in a High-Pollution Megacity: Influences of Atmospheric Condition and Land Coverage

by Carlos Zafra, Joaquín Suárez and Jorge E. Pachón

Atmosphere 2021, 12(1), 118; https://doi.org/10.3390/atmos12010118 - 15 Jan 2021

Cited by 6 | Viewed by 2286

Abstract

This paper analyzes the PM₁₀ concentrations and influences of atmospheric condition (AC) and land coverage (LC) on a high-pollution megacity (Bogota, Colombia) from a public health viewpoint. Information of monitoring stations equipped with measuring devices for PM₁₀/temperature/solar-radiation/wind-speed were used. The [...] Read more.

This paper analyzes the PM₁₀ concentrations and influences of atmospheric condition (AC) and land coverage (LC) on a high-pollution megacity (Bogota, Colombia) from a public health viewpoint. Information of monitoring stations equipped with measuring devices for PM₁₀/temperature/solar-radiation/wind-speed were used. The research period lasted eight years (2007–2014). AC and LC were determined after comparing daily PM₁₀ concentrations (DPM₁₀) to reference limits published by the World Health Organization (WHO). ARIMA models for DPM₁₀ were also developed. The results indicated that urban sectors with lower atmospheric instability (AI) had a 2.85% increase in daily mortality (DM) in relation to sectors with greater AI. In these sectors of lower AI, impervious LC predominated, instead of vegetated LC. An ARIMA analysis revealed that a greater extent of impervious LC around a station led to a greater effect on previous days’ DPM₁₀ concentrations. Extreme PM₁₀ episodes persisted for up to two days. Extreme pollution episodes were probably also preceded by low mixing-layer heights (between 722–1085 m). The findings showed a 13.0% increase in WHO standard excesses (PE) for each 10 µg/m³ increase in DPM₁₀, and a 0.313% increase in DM for each 10% increase in PE. The observed average reduction of 14.8% in DPM₁₀ (−0.79% in DM) was probably due to 40% restriction of the traffic at peak hours. Full article

(This article belongs to the Section Air Quality and Health)

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26 pages, 12130 KiB

Open AccessEditor’s ChoiceArticle

Understanding the Processes Causing the Early Intensification of Hurricane Dorian through an Ensemble of the Hurricane Analysis and Forecast System (HAFS)

by Andrew Hazelton, Ghassan J. Alaka, Jr., Levi Cowan, Michael Fischer and Sundararaman Gopalakrishnan

Atmosphere 2021, 12(1), 93; https://doi.org/10.3390/atmos12010093 - 10 Jan 2021

Cited by 10 | Viewed by 4321

Abstract

The early stages of a tropical cyclone can be a challenge to forecast, as a storm consolidates and begins to grow based on the local and environmental conditions. A high-resolution ensemble of the Hurricane Analysis and Forecast System (HAFS) is used to study [...] Read more.

The early stages of a tropical cyclone can be a challenge to forecast, as a storm consolidates and begins to grow based on the local and environmental conditions. A high-resolution ensemble of the Hurricane Analysis and Forecast System (HAFS) is used to study the early intensification of Hurricane Dorian, a catastrophic 2019 storm in which the early period proved challenging for forecasters. There was a clear connection in the ensemble between early storm track and intensity: stronger members moved more northeast initially, although this result did not have much impact on the long-term track. The ensemble results show several key factors determining the early evolution of Dorian. Large-scale divergence northeast of the tropical cyclone (TC) appeared to favor intensification, and this structure was present at model initialization. There was also greater moisture northeast of the TC for stronger members at initialization, favoring more intensification and downshear development of the circulation as these members evolved. This study highlights the complex interplay between synoptic and storm scale processes in the development and intensification of early-stage tropical cyclones. Full article

(This article belongs to the Special Issue Rapid Intensity Changes of Tropical Cyclones)

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8 pages, 255 KiB

Open AccessEditor’s ChoiceCommentary

Recent Advances in Studying Air Quality and Health Effects of Shipping Emissions

by Daniele Contini and Eva Merico

Atmosphere 2021, 12(1), 92; https://doi.org/10.3390/atmos12010092 - 9 Jan 2021

Cited by 50 | Viewed by 5480

Abstract

The increase of global commerce and tourism makes the shipping sector an important contributor of atmospheric particles and gaseous pollutants. These have impacts on both health and climate, especially in populated coastal areas. Maritime activities could be an important driver for economic and [...] Read more.

The increase of global commerce and tourism makes the shipping sector an important contributor of atmospheric particles and gaseous pollutants. These have impacts on both health and climate, especially in populated coastal areas. Maritime activities could be an important driver for economic and social development, however, they are also an environmental pressure. Several policies were implemented in the last decades, at local/regional or international levels, mainly focused on reducing the content of sulphur in marine fuels. The last international IMO-2020 regulation was enforced on 1 January 2020. This work reviews some recent studies on this topic delineating current knowledge of the impacts of maritime emissions on air quality and health and the future projections relative to the benefits of the implementation of the new IMO-2020 regulation. In addition, future perspectives for further mitigation strategies are discussed. Full article

(This article belongs to the Section Air Quality and Health)

12 pages, 2537 KiB

Open AccessEditor’s ChoiceArticle

Global Air Quality: An Inter-Disciplinary Approach to Exposure Assessment for Burden of Disease Analyses

by Gavin Shaddick, James M. Salter, Vincent-Henri Peuch, Giulia Ruggeri, Matthew L. Thomas, Pierpaolo Mudu, Oksana Tarasova, Alexander Baklanov and Sophie Gumy

Atmosphere 2021, 12(1), 48; https://doi.org/10.3390/atmos12010048 - 31 Dec 2020

Cited by 14 | Viewed by 4363

Abstract

Global assessments of air quality and health require comprehensive estimates of the exposures to air pollution that are experienced by populations in every country. However, there are many countries in which measurements from ground-based monitoring are sparse or non-existent, with quality-control and representativeness [...] Read more.

Global assessments of air quality and health require comprehensive estimates of the exposures to air pollution that are experienced by populations in every country. However, there are many countries in which measurements from ground-based monitoring are sparse or non-existent, with quality-control and representativeness providing additional challenges. While ground-based monitoring provides a far from complete picture of global air quality, there are other sources of information that provide comprehensive coverage across the globe. The World Health Organization developed the Data Integration Model for Air Quality (DIMAQ) to combine information from ground measurements with that from other sources, such as atmospheric chemical transport models and estimates from remote sensing satellites in order to produce the information that is required for health burden assessment and the calculation of air pollution-related Sustainable Development Goals indicators. Here, we show an example of the use of DIMAQ with the Copernicus Atmosphere Monitoring Service Re-Analysis (CAMSRA) of atmospheric composition, which represents the best practices in meteorology and climate monitoring that were developed under the World Meteorological Organization’s Global Atmosphere Watch programme. Estimates of PM_2.5 from CAMSRA are integrated within the DIMAQ framework in order to produce high-resolution estimates of air pollution exposure that can be aggregated in a coherent fashion to produce country-level assessments of exposures. Full article

(This article belongs to the Special Issue Health Impact Assessment of Air Pollution)

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19 pages, 9478 KiB

Open AccessEditor’s ChoiceArticle

Spatiotemporal Variations in Particulate Matter and Air Quality over China: National, Regional and Urban Scales

by Hao Luo, Yong Han, Xinghong Cheng, Chunsong Lu and Yonghua Wu

Atmosphere 2021, 12(1), 43; https://doi.org/10.3390/atmos12010043 - 30 Dec 2020

Cited by 10 | Viewed by 2959

Abstract

Ambient exposure to particulate matter (PM) air pollution is known to have an adverse effect on public health worldwide. Rapid increase rates of economic and urbanization, industrial development, and environmental change in China have exacerbated the occurrence of air pollution. This study examines [...] Read more.

Ambient exposure to particulate matter (PM) air pollution is known to have an adverse effect on public health worldwide. Rapid increase rates of economic and urbanization, industrial development, and environmental change in China have exacerbated the occurrence of air pollution. This study examines the temporal and spatial distribution of PM on national, regional and local scales in China during 2014–2016. The relationships between the PM_2.5 concentration rising rate (PMRR) and meteorological parameters (wind speed and wind direction) are discussed. The dataset of Air Quality Index (AQI), PM₁₀ (PM diameter < 10

μ m

) and PM_2.5 (PM diameter < 2.5

μ m

) were collected in 169, 369, and 367 cities in 2014, 2015, and 2016 over China, respectively. The results show that the air quality has been generally improved on the national scale, but deteriorated locally in areas such as the Feiwei Plain. The northwest China (NW) and Beijing-Tianjin-Hebei (BTH) regions are the worst areas of PM pollution, which are mainly manifested by the excessive PM₁₀ caused by blowing dust in spring in NW and the intensive emissions of PM_2.5 in winter in BTH. With the classified seven geographic regions, we demonstrate the significant spatial difference and seasonal variation of PM concentration and PM_2.5/PM₁₀ ratio, which indicate different emission sources. Furthermore, the dynamic analysis of the PM_2.5 pollution process in 11 large urban cities shows dramatic effects of wind speed and wind direction on the PM_2.5 loadings. Full article

(This article belongs to the Section Air Quality)

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12 pages, 4856 KiB

Open AccessEditor’s ChoiceArticle

Observational Analysis of Aerosol–Meteorology Interactions for the Severe Haze Episode in Korea

by Seung-Hee Eun, Sung-Min Park, Byung-Gon Kim, Jin-Soo Park and Ki-Ho Chang

Atmosphere 2021, 12(1), 33; https://doi.org/10.3390/atmos12010033 - 30 Dec 2020

Cited by 2 | Viewed by 2375

Abstract

Korea has occasionally suffered from various kinds of severe hazes such as long-range transported aerosol (LH), yellow sand (YS), and urban haze (UH). We classified haze days into LH, YS, and UH and analyzed the characteristics of its associated meteorological conditions for 2011–2016 [...] Read more.

Korea has occasionally suffered from various kinds of severe hazes such as long-range transported aerosol (LH), yellow sand (YS), and urban haze (UH). We classified haze days into LH, YS, and UH and analyzed the characteristics of its associated meteorological conditions for 2011–2016 using reanalysis data and surface observations. The results show that higher boundary layer height and stronger wind speed were found for the LH and YS hazes relative to those for UH. Intensive analysis on a golden episode of 10–18 January 2013 indicates that the cloud fraction increased along with extended light precipitation at a weaker rate by enhanced aerosol loading for an unprecedented LH event, which in turn brought about a decrease in boundary layer height (BLH) with less irradiance, that is, much stronger stability. Later, the intensified stability after the LH event accumulated and increased domestic aerosols, and eventually resulted in the longer-lasting severe haze. This study suggests that aerosol–meteorology interactions play an important role in both short-term weather and fine particle forecasts, especially on polluted days. Full article

(This article belongs to the Special Issue Aerosol-Climate Interaction)

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19 pages, 4511 KiB

Open AccessEditor’s ChoiceArticle

Real World Vehicle Emission Factors for Black Carbon Derived from Longterm In-Situ Measurements and Inverse Modelling

by Anne Wiesner, Sascha Pfeifer, Maik Merkel, Thomas Tuch, Kay Weinhold and Alfred Wiedensohler

Atmosphere 2021, 12(1), 31; https://doi.org/10.3390/atmos12010031 - 29 Dec 2020

Cited by 5 | Viewed by 3107

Abstract

Black carbon (BC) is one of the most harmful substances within traffic emissions, contributing considerably to urban pollution. Nevertheless, it is not explicitly regulated and the official laboratory derived emission factors are barely consistent with real world emissions. However, realistic emission factors (EFs) [...] Read more.

Black carbon (BC) is one of the most harmful substances within traffic emissions, contributing considerably to urban pollution. Nevertheless, it is not explicitly regulated and the official laboratory derived emission factors are barely consistent with real world emissions. However, realistic emission factors (EFs) are crucial for emission, exposure, and climate modelling. A unique dataset of 10 years (2009–2018) of roadside and background measurements of equivalent black carbon (eBC) concentration made it possible to estimate real world traffic EFs and observe their change over time. The pollutant dispersion was modelled using the Operational Street Pollution Model (OSPM). The EFs for eBC are derived for this specific measurement site in a narrow but densely trafficked street canyon in Leipzig, Germany. The local conditions and fleet composition can be considered as typical for an inner-city traffic scenario in a Western European city. The fleet is composed of 22% diesel and 77% petrol cars in the passenger car segment, with an unknown proportion of direct injection engines. For the mixed fleet the eBC EF was found to be 48 mg km

^{- 1}

in the long-term average. Accelerated by the introduction of a low emission zone, the EFs decreased over the available time period from around 70 mg km

^{- 1}

to 30–40 mg km

^{- 1}

. Segregation into light (<3.5 t) and heavy (>3.5 t) vehicles resulted in slightly lower estimates for the light vehicles than for the mixed fleet, and one order of magnitude higher values for the heavy vehicles. The found values are considerably higher than comparable emission standards for particulate matter and even the calculations of the Handbook Emission Factors for Road Transport (HBEFA), which is often used as emission model input. Full article

(This article belongs to the Section Aerosols)

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10 pages, 2094 KiB

Open AccessEditor’s ChoiceArticle

Microbial Monitoring as a Tool for Preventing Infectious Risk in the Operating Room: Results of 10 Years of Activity

by Maria Dolores Masia, Marco Dettori, Grazia Maria Deriu, Serena Soddu, Michela Deriu, Antonella Arghittu, Antonio Azara and Paolo Castiglia

Atmosphere 2021, 12(1), 19; https://doi.org/10.3390/atmos12010019 - 25 Dec 2020

Cited by 15 | Viewed by 3841

Abstract

Environmental microbial contamination in the operating room (OR) can favour contamination of the surgical wound, posing the risk of infection of the surgical site. Thus, environmental monitoring is a useful tool for assessing environmental health and the effectiveness and efficiency of the measures [...] Read more.

Environmental microbial contamination in the operating room (OR) can favour contamination of the surgical wound, posing the risk of infection of the surgical site. Thus, environmental monitoring is a useful tool for assessing environmental health and the effectiveness and efficiency of the measures adopted to control the risk of infection in the OR. This work aimed to analyse the long term environmental quality of 18 ORs throughout Sardinia, Italy, through the quantitative and qualitative characterisation of the microbial flora present in the air and on surfaces, in order to evaluate the trend over time, including in relation to any control measures adopted. The results of the sampling carried out in the period from January 2010 to December 2019 have been extrapolated from the archive-database of the Laboratory of the Hygiene and Control of Hospital Infections Unit of the University Hospital in Sassari. During the period in question, 188 air evaluations were carried out, both in empty rooms and during surgery, and 872 surface samples were taken. When the air was monitored, it emerged that significant contamination was detectable in a reduced number of examinations and a limited number of rooms. Microbial load values higher than the reference values may have been mainly determined by sub-optimal operation/maintenance of the air conditioning system. Surface testing showed a good level of sanitisation, given the low percentage of non-compliant values detected. The possibility of having data available on environmental quality is a useful educational and training tool both for those responsible for sanitisation procedures and the surgical team, in order to increase awareness of the effects of a lack of compliance with behavioural standards. Full article

(This article belongs to the Special Issue Indoor Air Quality in Healthcare Facilities and Healing Environments)

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24 pages, 2445 KiB

Open AccessEditor’s ChoiceArticle

Evaluation of Multiple Approaches to Estimate Daily Solar Radiation for Input to Crop Process Models

by Perdinan, Julie A. Winkler and Jeffrey A. Andresen

Atmosphere 2021, 12(1), 8; https://doi.org/10.3390/atmos12010008 - 23 Dec 2020

Cited by 3 | Viewed by 2653

Abstract

Daily solar radiation is a critical input for estimating plant growth and development, yet this variable is infrequently measured compared to other climate variables. This study evaluates the sensitivity of simulated maize and soybean production from the CERES-Maize and CROPGRO-Soybean modules of the [...] Read more.

Daily solar radiation is a critical input for estimating plant growth and development, yet this variable is infrequently measured compared to other climate variables. This study evaluates the sensitivity of simulated maize and soybean production from the CERES-Maize and CROPGRO-Soybean modules of the Decision Support System for Agrotechnology Transfer (DSSAT) to daily solar radiation estimates obtained from traditional (stochastic, empirical, and mechanistic models) and non-traditional (satellite estimation, reanalysis datasets, and regional climate model simulations) approaches, using as an example radiation estimates for Hancock, Wisconsin, USA. When compared to observations, radiation estimates obtained from empirical and mechanistic models and a satellite-based dataset generally had smaller biases than other approaches. Daily solar radiation estimates from a reanalysis dataset and regional climate model simulations overestimate incoming daily solar radiation. When the radiation estimates were used as an input to CERES-Maize, no significant differences were found for maize yield obtained from the different radiation estimates compared to yield from observed radiation, even though differences were found in the daily values of leaf area index, crop evapotranspiration, and crop dry weight (biomass). In contrast, significant differences were found in simulated soybean yield from CROPGRO-Soybean for the majority of the radiation estimates. Full article

(This article belongs to the Special Issue Climate Data for Agricultural Applications: Downscaling and Scenarios)

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26 pages, 25251 KiB

Open AccessEditor’s ChoiceArticle

Graz Lagrangian Model (GRAL) for Pollutants Tracking and Estimating Sources Partial Contributions to Atmospheric Pollution in Highly Urbanized Areas

by Aleksey A. Romanov, Boris A. Gusev, Egor V. Leonenko, Anastasia N. Tamarovskaya, Alexander S. Vasiliev, Nikolai E. Zaytcev and Ilia K. Philippov

Atmosphere 2020, 11(12), 1375; https://doi.org/10.3390/atmos11121375 - 19 Dec 2020

Cited by 18 | Viewed by 8817

Abstract

Computational modeling allows studying the air quality problems in depth and provides the best solution reducing the population risks. This research demonstrates the Graz Lagrangian model effectiveness for assessing emission sources contributions to the air pollution: particles tracking and accumulation estimate. The article [...] Read more.

Computational modeling allows studying the air quality problems in depth and provides the best solution reducing the population risks. This research demonstrates the Graz Lagrangian model effectiveness for assessing emission sources contributions to the air pollution: particles tracking and accumulation estimate. The article describes model setting up parameters and datasets preparation for the analysis. The experiment simulated the dispersion from the main groups of emission sources for real weather conditions during 96 h of December 2018, when significant excess of NO₂, CO, SO₂, PM10, and benzo(a)pyrene concentrations were observed in the Krasnoyarsk surface atmospheric layer. The computational domain was a parallelepiped of 40 × 30 × 2.5 km, which was located deep inside the Eurasian continent on a heterogeneous landscape exaggerated by high-rise buildings, with various pollutions sources and the ice-free Yenisei River. The results demonstrated an excellent applicability of the Lagrange model for hourly tracking of particle trajectories, taking into account the urban landscape. For values <1 MPC (maximum permissible concentration) of peak pollutants concentrations, the coincidences were 93 cases, and for values < 0.1 shares of MPC, there were 36 cases out of the total number of 97. The same was found for the average daily concentration for values <1 MPC—31, and for values <0.1 MPC—5 matches out of 44. Wind speeds COR—65.3%, wind directions COR—68.6%. The Graz Lagrangian model showed the ability to simulate air quality problems in the Krasnoyarsk greater area conditions. Full article

(This article belongs to the Special Issue Atmospheric Trace Gas Source Detection and Quantification)

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27 pages, 8504 KiB

Open AccessEditor’s ChoiceArticle

A Long-Term, 1-km Resolution Daily Meteorological Dataset for Modeling and Mapping Permafrost in Canada

by Yu Zhang, Budong Qian and Gang Hong

Atmosphere 2020, 11(12), 1363; https://doi.org/10.3390/atmos11121363 - 16 Dec 2020

Cited by 3 | Viewed by 4174

Abstract

Climate warming is causing permafrost thaw and there is an urgent need to understand the spatial distribution of permafrost and its potential changes with climate. This study developed a long-term (1901–2100), 1-km resolution daily meteorological dataset (Met1km) for modeling and mapping permafrost at [...] Read more.

Climate warming is causing permafrost thaw and there is an urgent need to understand the spatial distribution of permafrost and its potential changes with climate. This study developed a long-term (1901–2100), 1-km resolution daily meteorological dataset (Met1km) for modeling and mapping permafrost at high spatial resolutions in Canada. Met1km includes eight climate variables (daily minimum, maximum, and mean air temperatures, precipitation, vapor pressure, wind speed, solar radiation, and downward longwave radiation) and is suitable to drive process-based permafrost and other land-surface models. Met1km was developed based on four coarser gridded meteorological datasets for the historical period. Future values were developed using the output of a new Canadian regional climate model under medium-low and high emission scenarios. These datasets were downscaled to 1-km resolution using the re-baselining method based on the WorldClim2 dataset as spatial templates. We assessed Met1km by comparing it to climate station observations across Canada and a gridded monthly anomaly time-series dataset. The accuracy of Met1km is similar to or better than the four coarser gridded datasets. The errors in long-term averages and average seasonal patterns are small. The error occurs mainly in day-to-day fluctuations, thus the error decreases significantly when averaged over 5 to 10 days. Met1km, as a data generating system, is relatively small in data volume, flexible to use, and easy to update when new or improved source datasets are available. The method can also be used to generate similar datasets for other regions, even for the entire global landmass. Full article

(This article belongs to the Special Issue Climate Data for Agricultural Applications: Downscaling and Scenarios)

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12 pages, 10892 KiB

Open AccessEditor’s ChoiceArticle

Air Pollution and Long Term Mental Health

by Younoh Kim, James Manley and Vlad Radoias

Atmosphere 2020, 11(12), 1355; https://doi.org/10.3390/atmos11121355 - 14 Dec 2020

Cited by 24 | Viewed by 4297

Abstract

We study the long-term consequences of air pollution on mental health, using a natural experiment in Indonesia. We find that exposure to severe air pollution has significant and persistent consequences on mental health. An extra standard deviation in the pollution index raises the [...] Read more.

We study the long-term consequences of air pollution on mental health, using a natural experiment in Indonesia. We find that exposure to severe air pollution has significant and persistent consequences on mental health. An extra standard deviation in the pollution index raises the probability of clinical depression measured 10 years past exposure by almost 1%. Women in particular seem to be more affected, but some effects persist for men as well. Pollution exposure increases the likelihood of clinical depression for women and also the severity of depressive symptoms for both sexes. It is not clear if men are more resistant to pollution or they simply recover faster from it. Education, perceived economic status, and marriage seem to be the best mitigators for these negative effects. Full article

(This article belongs to the Special Issue Contributions of Aerosol Sources to Health Impacts)

26 pages, 7095 KiB

Open AccessEditor’s ChoiceArticle

The Microscale Urban Surface Energy (MUSE) Model for Real Urban Application

by Doo-Il Lee and Sang-Hyun Lee

Atmosphere 2020, 11(12), 1347; https://doi.org/10.3390/atmos11121347 - 12 Dec 2020

Cited by 5 | Viewed by 2575

Abstract

Urban atmospheric environmental issues are commonly associated with the physical processes of urban surfaces. Much progress has been made on the building-resolving microscale atmospheric models, but a realistic representation of the physical processes of urban surfaces on those models is still lacking. This [...] Read more.

Urban atmospheric environmental issues are commonly associated with the physical processes of urban surfaces. Much progress has been made on the building-resolving microscale atmospheric models, but a realistic representation of the physical processes of urban surfaces on those models is still lacking. This study presents a new microscale urban surface energy (MUSE) model for real urban meteorological and environmental applications that is capable of representing the urban radiative, convective, and conductive energy transfer processes along with their interactions, and that is directly compatible with the Cartesian grid microscale atmospheric models. The physical processes of shadow casting and radiative transfers were validated on an analytical accuracy level. The full capability of the model in simulating the three-dimensional surface heterogeneities in a real urban environment was tested for a hot summer day in August 2016 using the field measurements obtained from the Kongju National University campus, South Korea. The validation against the measurements showed that the model is capable of predicting surface temperatures and energy balance fluxes in a patch scale at the heterogeneous urban surfaces by virtue of the interactive representation of the urban physical processes. The excellent performance and flexible grid design emphasize the potential capabilities of the MUSE model for use in urban meteorological and environmental applications through the building-resolving microscale atmospheric models, such as computational fluid dynamics (CFD) and large-eddy simulations (LES). Full article

(This article belongs to the Section Atmospheric Techniques, Instruments, and Modeling)

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17 pages, 5377 KiB

Open AccessEditor’s ChoiceArticle

High Latitude Dust Transport Altitude Pattern Revealed from Deposition on Snow, Svalbard

by Jan Kavan, Kamil Láska, Adam Nawrot and Tomasz Wawrzyniak

Atmosphere 2020, 11(12), 1318; https://doi.org/10.3390/atmos11121318 - 6 Dec 2020

Cited by 8 | Viewed by 3505

Abstract

High Latitude Dust (HLD) deposition in the surface snow layer in two distant locations in Svalbard (Hornsund and Pyramiden) were collected during the June/July 2019 field campaign and examined in the laboratory. Despite the differences in their climate and topography, both locations are [...] Read more.

High Latitude Dust (HLD) deposition in the surface snow layer in two distant locations in Svalbard (Hornsund and Pyramiden) were collected during the June/July 2019 field campaign and examined in the laboratory. Despite the differences in their climate and topography, both locations are characterised by very similar spatial patterns of the deposition. On the one hand, strong linear negative relationship between the altitude of the sample taken and its concentration was found in low altitude (below 300 m a.s.l.), suggesting a strong influence of local HLD sources. On the other hand, almost constant concentrations were found at higher elevated sampling sites (above 300 m a.s.l.). This suggests a predominantly long-range transport in high altitude areas. The importance of local sources in the lower altitude corresponds well with the generally higher concentrations of HLD in the Pyramiden area. This region has a drier, continental climate and more deglaciated bare land surfaces, which favour more sediment to be uplifted in comparison with the more maritime climate of Hornsund area in the southern part of Svalbard. The spatial division between the local and long-range transport is supported by the proportion of certain lithophile elements in the altitude gradient. Full article

(This article belongs to the Special Issue Long-Range Transport of Dust over the High-Latitude Regions)

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21 pages, 8049 KiB

Open AccessEditor’s ChoiceArticle

Smart Climate Hydropower Tool: A Machine-Learning Seasonal Forecasting Climate Service to Support Cost–Benefit Analysis of Reservoir Management

by Arthur H. Essenfelder, Francesca Larosa, Paolo Mazzoli, Stefano Bagli, Davide Broccoli, Valerio Luzzi, Jaroslav Mysiak, Paola Mercogliano and Francesco dalla Valle

Atmosphere 2020, 11(12), 1305; https://doi.org/10.3390/atmos11121305 - 1 Dec 2020

Cited by 14 | Viewed by 3944

Abstract

This study proposes a climate service named Smart Climate Hydropower Tool (SCHT) and designed as a hybrid forecast system for supporting decision-making in a context of hydropower production. SCHT is technically designed to make use of information from state-of-art seasonal forecasts provided by [...] Read more.

This study proposes a climate service named Smart Climate Hydropower Tool (SCHT) and designed as a hybrid forecast system for supporting decision-making in a context of hydropower production. SCHT is technically designed to make use of information from state-of-art seasonal forecasts provided by the Copernicus Climate Data Store (CDS) combined with a range of different machine learning algorithms to perform the seasonal forecast of the accumulated inflow discharges to the reservoir of hydropower plants. The machine learning algorithms considered include support vector regression, Gaussian processes, long short-term memory, non-linear autoregressive neural networks with exogenous inputs, and a deep-learning neural networks model. Each machine learning model is trained over past decades datasets of recorded data, and forecast performances are validated and evaluated using separate test sets with reference to the historical average of discharge values and simpler multiparametric regressions. Final results are presented to the users through a user-friendly web interface developed from a tied connection with end-users in an effective co-design process. Methods are tested for forecasting the accumulated seasonal river discharges up to six months in advance for two catchments in Colombia, South America. Results indicate that the machine learning algorithms that make use of a complex and/or recurrent architecture can better simulate the temporal dynamic behaviour of the accumulated river discharge inflow to both case study reservoirs, thus rendering SCHT a useful tool in providing information for water resource managers in better planning the allocation of water resources for different users and for hydropower plant managers when negotiating power purchase contracts in competitive energy markets. Full article

(This article belongs to the Special Issue Artificial Intelligence and Machine Learning: Application in Predictive Hydrological Models)

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17 pages, 4437 KiB

Open AccessEditor’s ChoiceArticle

Future Crop Yield Projections Using a Multi-model Set of Regional Climate Models and a Plausible Adaptation Practice in the Southeast United States

by D. W. Shin, Steven Cocke, Guillermo A. Baigorria, Consuelo C. Romero, Baek-Min Kim and Ki-Young Kim

Atmosphere 2020, 11(12), 1300; https://doi.org/10.3390/atmos11121300 - 30 Nov 2020

Cited by 5 | Viewed by 2599

Abstract

Since maize, peanut, and cotton are economically valuable crops in the southeast United States, their yield amount changes in a future climate are attention-grabbing statistics demanded by associated stakeholders and policymakers. The Crop System Modeling—Decision Support System for Agrotechnology Transfer (CSM-DSSAT) models of [...] Read more.

Since maize, peanut, and cotton are economically valuable crops in the southeast United States, their yield amount changes in a future climate are attention-grabbing statistics demanded by associated stakeholders and policymakers. The Crop System Modeling—Decision Support System for Agrotechnology Transfer (CSM-DSSAT) models of maize, peanut, and cotton are, respectively, driven by the North American Regional Climate Change Assessment Program (NARCCAP) Phase II regional climate models to estimate current (1971–2000) and future (2041–2070) crop yield amounts. In particular, the future weather/climate data are based on the Special Report on Emission Scenarios (SRES) A2 emissions scenario. The NARCCAP realizations show on average that there will be large temperature increases (~2.7 °C) and minor rainfall decreases (~−0.10 mm/day) with pattern shifts in the southeast United States. With these future climate projections, the overall future crop yield amounts appear to be reduced under rainfed conditions. A better estimate of future crop yield amounts might be achievable by utilizing the so-called weighted ensemble method. It is proposed that the reduced crop yield amounts in the future could be mitigated by altering the currently adopted local planting dates without any irrigation support. Full article

(This article belongs to the Special Issue Advances in Improving Crop Adaptation in a Changing Climate)

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23 pages, 16302 KiB

Open AccessEditor’s ChoiceArticle

Monitoring Dust Events Using Doppler Lidar and Ceilometer in Iceland

by Shu Yang, Jana Preißler, Matthias Wiegner, Sibylle von Löwis, Guðrún Nína Petersen, Michelle Maree Parks and David Christian Finger

Atmosphere 2020, 11(12), 1294; https://doi.org/10.3390/atmos11121294 - 30 Nov 2020

Cited by 17 | Viewed by 4022

Abstract

Ground-based lidars and ceilometers are widely used for dust and volcanic ash observation around the world. This is particularly interesting in Iceland where high-altitude dust events occur frequently during strong wind conditions and volcanic eruptions. To explore the possible application of such technologies [...] Read more.

Ground-based lidars and ceilometers are widely used for dust and volcanic ash observation around the world. This is particularly interesting in Iceland where high-altitude dust events occur frequently during strong wind conditions and volcanic eruptions. To explore the possible application of such technologies in Iceland for monitoring dust events, we used a combination of Doppler wind lidars with depolarization channels, ceilometers, and other instruments, to monitor two dust events that occurred in Iceland during summer 2019. We applied a verified ceilometer data processing procedure with customized local corrections and developed a new procedure to process Doppler lidar data for aerosols measurements. Both lidar and ceilometer observations can be used to detect the dust layer and reveal the temporal and vertical distribution of dust aerosols in Iceland. The depolarization ratio measurements indicate that the weather conditions, e.g., relative humidity, could have a significant impact on lidar measurements. We conclude that using Doppler wind lidar and ceilometer measurements to monitor volcanic and sedimentary aerosols is possible and may be used to provide important information to the scientific community. Full article

(This article belongs to the Special Issue Lidar Remote Sensing Techniques for Atmospheric Aerosols)

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17 pages, 9084 KiB

Open AccessEditor’s ChoiceArticle

Association between the Concentration and the Elemental Composition of Outdoor PM_2.5 and Respiratory Diseases in Schoolchildren: A Multicenter Study in the Mediterranean Area

by Christopher Zammit, David Bilocca, Silvia Ruggieri, Gaspare Drago, Cinzia Perrino, Silvia Canepari, Martin Balzan, Stephen Montefort, Giovanni Viegi, Fabio Cibella and on behalf of the RESPIRA Collaborative Project Group

Atmosphere 2020, 11(12), 1290; https://doi.org/10.3390/atmos11121290 - 29 Nov 2020

Cited by 5 | Viewed by 2582

Abstract

Abstract: Exposure to outdoor air pollution has been shown to increase asthma symptoms. We assessed the potential role of particulate matter with aerodynamic diameter <2.5 μm (PM_2.5) on respiratory condition in schoolchildren in the south Mediterranean area. A total of [...] Read more.

Abstract: Exposure to outdoor air pollution has been shown to increase asthma symptoms. We assessed the potential role of particulate matter with aerodynamic diameter <2.5 μm (PM_2.5) on respiratory condition in schoolchildren in the south Mediterranean area. A total of 2400 children aged 11–14 years were recruited, and data on their symptoms were collected through an ISAAC (International Study of Asthma and Allergies in Childhood)-based questionnaire. Outdoor PM_2.5 was collected for 48 consecutive hours in the schoolyards of their schools and selected residential outdoor areas. The levels of PM_2.5 were measured, along with its elemental composition. The incidence of an acute respiratory illness within the first 2 years of life was higher amongst Sicilian children when compared to Maltese children (29.7% vs. 13.5% respectively, p < 0.0001). Malta had a significantly higher prevalence of doctor‐diagnosed asthma, when compared to Sicily (18.0% Malta vs. 7.5% Sicily, p <0.0001). Similarly, current asthma (7.8% vs. 2.9%, p < 0.0001) and use of asthma medication in the last 12 months (12.1% vs. 4.9%, p < 0.0001) were more frequent amongst Maltese children. Total median PM_2.5 was 12.9 μg/m³ in Sicily and 17.9 μg/m³ in Malta. PM_2.5 levels were highest in the Maltese urban town of Hamrun (23.6 μg/m³), while lowest in the rural Sicilian town of Niscemi (10.9 μg/m³, p < 0.0001). Hamrun also exhibited the highest levels of nickel, vanadium, lead, zinc, antimony, and manganese, whilst the Sicilian city of Gela had the highest levels of cadmium, and the highest level of PM_2.5 when compared to rural Sicily. Elevated levels of PM_2.5 were positively associated with the prevalence of doctor diagnosed asthma (odds ratio (OR) 1.05), current asthma (OR 1.06), and use of asthma medication (OR 1.06). All elements in PM_2.5 showed increased OR for doctor diagnosed asthma, while higher concentrations of Cd and Mn were associated with higher prevalence of rhinitis. Full article

(This article belongs to the Special Issue Air Quality and Health in the Mediterranean)

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18 pages, 1449 KiB

Open AccessEditor’s ChoiceCommunication

A Note on the Assessment of the Effect of Atmospheric Factors and Components on Humans

by Andreas Matzarakis

Atmosphere 2020, 11(12), 1283; https://doi.org/10.3390/atmos11121283 - 28 Nov 2020

Cited by 14 | Viewed by 2456

Abstract

The aim of this contribution is both to demonstrate and to explore the general assessment pertaining to the effects of atmospheric factors on human health and general wellbeing. While humans are aware of such effects, particularly individually, their concrete and synergetic effects with [...] Read more.

The aim of this contribution is both to demonstrate and to explore the general assessment pertaining to the effects of atmospheric factors on human health and general wellbeing. While humans are aware of such effects, particularly individually, their concrete and synergetic effects with the human physiological system are, comparatively, not well comprehended. In human biometeorological studies and approaches, the aforementioned effects are analyzed in terms of their effect pathways, and the development of single or complex approaches. Recurrently in the existing literature, such approaches are mostly defined and, respectively, targeted as indexes. The evaluation and assessment of similar factors and parameters that present related effects were subsequently put together and quantified. This approach is described as ‘effective complexes’ or components. The most well-known examples are the thermal complex, air pollution complex (which can be divided into the biological (pollen) and anthropogenic (air pollutants) factors), actinic complex, and finally, the recent or rapid weather changes complex. Most of the approaches focus on the negative effects consequential to the established criteria ranging from empirical outputs, to epidemiological studies. As a result, the presented approach does not only include the negative effects or implications on humans. Instead, it also highlights the neutral and positive effects which were acknowledged by the research. The approach deals furthermore with the combined effects of different complexes or components and incorporates different weightings of the factors based on the disclosed effects. In addition, seasonal and exposure factors are deliberated upon to differentiate annual variability factors. Finally, the presented approach builds upon a way in which to cogitate how the complex interactions associated to weather and climate can be quantified in a more appropriate way in the context of human health. The approach aims to be applied for a specific weather forecast enabling the communication and balance between human health factors, and also more encompassing climatic analysis. Full article

(This article belongs to the Special Issue Review Special Issue: Human Biometeorology—Link to Climate Impact Research)

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15 pages, 8154 KiB

Open AccessEditor’s ChoiceArticle

Spatial and Temporal Exposure Assessment to PM_2.5 in a Community Using Sensor-Based Air Monitoring Instruments and Dynamic Population Distributions

by Jinhyeon Park, Wondeuk Jo, Mansu Cho, Jeongil Lee, Hunjoo Lee, SungChul Seo, Chulmin Lee and Wonho Yang

Atmosphere 2020, 11(12), 1284; https://doi.org/10.3390/atmos11121284 - 28 Nov 2020

Cited by 10 | Viewed by 3740

Abstract

This research was to conduct a pilot study for two consecutive days in order to assess fine particulate matter (PM_2.5) exposure of an entire population in a community. We aimed to construct a surveillance system by analyzing the observed spatio-temporal variation [...] Read more.

This research was to conduct a pilot study for two consecutive days in order to assess fine particulate matter (PM_2.5) exposure of an entire population in a community. We aimed to construct a surveillance system by analyzing the observed spatio-temporal variation of exposure. Guro-gu in Seoul, South Korea, was divided into 2,204 scale grids of 100 m each. Hourly exposure concentrations of PM_2.5 were modeled by the inverse distance weighted method, using 24 sensor-based air monitoring instruments and the indoor-to-outdoor concentration ratio. Population distribution was assessed using mobile phone network data and indoor residential rates, according to sex and age over time. Exposure concentration, population distribution, and population exposure were visualized to present spatio-temporal variation. The PM_2.5 exposure of the entire population of Guro-gu was calculated by population-weighted average exposure concentration. The average concentration of outdoor PM_2.5 was 42.1 µg/m³, which was lower than the value of the beta attenuation monitor measured by fixed monitoring station. Indoor concentration was estimated using an indoor-to-outdoor PM_2.5 concentration ratio of 0.747. The population-weighted average exposure concentration of PM_2.5 was 32.4 µg/m³. Thirty-one percent of the population exceeded the Korean Atmospheric Environmental Standard for PM_2.5 over a 24 h average period. The results of this study can be used in a long-term aggregate and cumulative PM_2.5 exposure assessment, and as a basis for policy decisions on public health management among policymakers and stakeholders. Full article

(This article belongs to the Special Issue Challenges in Measuring and Assessing Environmental Health)

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19 pages, 6881 KiB

Open AccessEditor’s ChoiceArticle

Impact of Meteorological Changes on Particulate Matter and Aerosol Optical Depth in Seoul during the Months of June over Recent Decades

by Seohee H. Yang, Jaein I. Jeong, Rokjin J. Park and Minjoong J. Kim

Atmosphere 2020, 11(12), 1282; https://doi.org/10.3390/atmos11121282 - 27 Nov 2020

Cited by 11 | Viewed by 3006

Abstract

The effects of meteorological changes on particulate matter with a diameter of 10 microns or less (PM₁₀, referred to as PM in this study) and aerosol optical depth (AOD) in Seoul were investigated using observational and modeling analysis. AOD satellite data [...] Read more.

The effects of meteorological changes on particulate matter with a diameter of 10 microns or less (PM₁₀, referred to as PM in this study) and aerosol optical depth (AOD) in Seoul were investigated using observational and modeling analysis. AOD satellite data were used, obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS), and PM concentration data were used from in-situ observations. The Modern-Era Retrospective Analysis for Research and Applications (MERRA) and MERRA Version 2 (MERRA-2) were used for meteorological field analysis in modeling and observation data. The results from this investigation show that meteorological effects on PM and AOD were strong in the month of June, revealing a clear decreasing trend in recent decades. The investigation focused on the underlying mechanisms influencing the reduction in PM resulting from meteorological changes during the months of June. The results of this study reveal that decreases in atmospheric stability and humidity induced the aerosol change observed in recent decades. The changes in atmospheric stability and humidity are highly correlated with changes in the intensity of the East Asian summer monsoon (EASM). This suggests that the unstable and drying atmosphere by weakening of the EASM in recent decades has improved PM air quality in Seoul during the summer. The effects of atmospheric stability and humidity were also observed to vary depending on the aerosol species. Humidity only affects hydrophilic aerosols such as sulfate, nitrate, and ammonium, whereas atmospheric stability affects all species of aerosols, including carbonaceous aerosols. Full article

(This article belongs to the Special Issue Aerosol-Climate Interaction)

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19 pages, 3820 KiB

Open AccessEditor’s ChoiceArticle

Representation of the 2016 Korean Heatwave in the Unified Model Global NWP Forecasts: The Impact of Remotely Forced Model Errors and Atmosphere-Ocean Coupling

by Eun-Jung Kim, Charline Marzin, Sean F. Milton, Kyung-On Boo, Yoonjae Kim, Jiyoung Oh and Hyun-Suk Kang

Atmosphere 2020, 11(12), 1275; https://doi.org/10.3390/atmos11121275 - 25 Nov 2020

Cited by 3 | Viewed by 2187

Abstract

This study investigates the effects of atmosphere-ocean coupling for medium-range forecasts by using coupled numerical weather prediction (NWP) experiments based on the unified model (UM) on a case study of the 2016 heatwave over the Korean Peninsula. Atmospheric nudging experiments were carried out [...] Read more.

This study investigates the effects of atmosphere-ocean coupling for medium-range forecasts by using coupled numerical weather prediction (NWP) experiments based on the unified model (UM) on a case study of the 2016 heatwave over the Korean Peninsula. Atmospheric nudging experiments were carried out to determine the key regions which may have large impacts on the forecasts of the heat wave. The results of the nudging experiments suggest that key forcing from the Mongolia region gives the largest impact to this case by causing a transport of warm air from the northwest part of Korea. Moreover, the Pacific region shows an important role in the global circulation in nudging experiments. Results from the atmosphere-ocean coupled model show no clear benefit for the extreme heat wave temperatures in this case. In addition, more model development seems to be needed to improve the representation of sea surface temperature (SST) in some key areas. Nevertheless, it is confirmed that the atmosphere-ocean coupled simulation produces a better representation of aspects of the large-scale flow such as the blocking high over the Kamchatka Peninsula, the high pressure system in the northwest Pacific and Hadley circulation. The results presented in this study show that atmosphere-ocean coupling can be an important way to improve the deterministic model forecasts as the lead time increases beyond a few days. Full article

(This article belongs to the Special Issue Meteorological Extremes in Korea: Prediction, Assessment, and Impact)

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13 pages, 8980 KiB

Open AccessEditor’s ChoiceArticle

A Hot Blob Eastward of New Zealand in December 2019

by Jian Shi, Ziyan Chen, Saisai Ding and Yiqun Lu

Atmosphere 2020, 11(12), 1267; https://doi.org/10.3390/atmos11121267 - 24 Nov 2020

Cited by 2 | Viewed by 2554

Abstract

A hot blob for near-surface water was identified eastward of New Zealand in the South Pacific in December 2019, which was the second strongest event on record in this region. Its sea surface temperature anomalies reached up to 5 °C, and the anomalous [...] Read more.

A hot blob for near-surface water was identified eastward of New Zealand in the South Pacific in December 2019, which was the second strongest event on record in this region. Its sea surface temperature anomalies reached up to 5 °C, and the anomalous warming penetrated around 40 m deep vertically. From the atmospheric perspective, the anomalous high-pressure system from the surface up to 300 hPa lasted for about 50 days, accompanied by the blocking pattern at 500 hPa and a deep warming air column extending downward to the surface. A mixed-layer heat budget analysis revealed that the surface heat flux term was the primary factor contributing to the development of this hot blob, with more shortwave radiation due to the persistent high-pressure system and lack of clouds as well as higher temperature of the troposphere aloft denoted by sensible heat. The oceanic contribution including the horizontal advection and vertical entrainment was changeable and accounted for less than 50%. Moreover, we used the strongest hot blob event which peaked in December 2001 as another example to evaluate the robustness of results derived from the 2019 case. The results show similar circulation features and driving factors, which indicate the robustness of the above characteristics. Full article

(This article belongs to the Special Issue Temperature Extremes and Atmospheric Circulation)

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25 pages, 3470 KiB

Open AccessEditor’s ChoiceArticle

New Record of Dust Input and Provenance During Glacial Periods in Western Australia Shelf (IODP Expedition 356, Site U1461) from the Middle to Late Pleistocene

by Margot Courtillat, Maximilian Hallenberger, Maria-Angela Bassetti, Dominique Aubert, Catherine Jeandel, Lars Reuning, Chelsea Korpanty, Pierre Moissette, Stéphanie Mounic and Mariem Saavedra-Pellitero

Atmosphere 2020, 11(11), 1251; https://doi.org/10.3390/atmos11111251 - 20 Nov 2020

Cited by 10 | Viewed by 4535

Abstract

International Ocean Discovery Program (IODP) Expedition 356 Site U1461 represents one of the few records from the North West Australian shelf that provides information about aridity fluctuations in Australia during the Quaternary. A combination of chronostratigraphic indicators revealed the (partial) preservation of two [...] Read more.

International Ocean Discovery Program (IODP) Expedition 356 Site U1461 represents one of the few records from the North West Australian shelf that provides information about aridity fluctuations in Australia during the Quaternary. A combination of chronostratigraphic indicators revealed the (partial) preservation of two major glaciations (Marine Isotope Stage (MIS) 2 and MIS 12) in the sedimentary record. The faunal content (mainly benthic foraminifera, corals and bryozoans) was analyzed to estimate paleo-environments and paleo-depths in order to determine if these sediments have been remobilized by reworking processes. Despite the occurrence of a depositional hiatus (including MIS 5d to MIS 9-time interval), the excellent preservation of faunal content suggests that the preserved sediment is in situ. The geochemical composition of the sediments (Nd and major elements) indicates that during MIS 12 riverine input was likely reduced because of enhanced aridity, and the sediment provenance (mainly atmospheric dust) is likely in the central (Lake Eyre) or eastern (Murray Darling Basin) parts of the Australian continent. MIS 2 is confirmed to be one of the driest periods recorded in Australia but with mixed dust sources from the eastern and western parts of the continent. More humid conditions followed the glacial maximum, which might correspond to the peak of the Indian-Australian Summer Monsoon. Full article

(This article belongs to the Special Issue Paleoclimate and Its Connection with Future Climate Change)

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18 pages, 3726 KiB

Open AccessEditor’s ChoiceArticle

Regional Distribution of Net Radiation over Different Ecohydrological Land Surfaces

by Md Masudur Rahman, Wanchang Zhang and Arfan Arshad

Atmosphere 2020, 11(11), 1229; https://doi.org/10.3390/atmos11111229 - 14 Nov 2020

Cited by 3 | Viewed by 3362

Abstract

Net radiation is an important component of the earth’s surface energy balance, which plays a vital role in the evolution of regional climate or climate change. The estimation of this component at regional or global scales is critical and challenging due to the [...] Read more.

Net radiation is an important component of the earth’s surface energy balance, which plays a vital role in the evolution of regional climate or climate change. The estimation of this component at regional or global scales is critical and challenging due to the sparse and limited ground-based observations. This paper made an attempt to analyze the feasibility of a remote sensing-based surface energy balance model using satellite (TERRA/MODIS) data to derive the net radiation (R_n). In the present study, MODIS data at 15 different days of the year (DOY) were utilized to visualize the spatial pattern of net radiation flux over three versatile and heterogeneous ecohydrological land surfaces (upstream, midstream, and downstream) of northwest China (Heihe river basin). The results revealed that the estimated net radiation from the satellite data agrees well with the ground-based measurements over three different surfaces, with a mean relative error of 9.33% over the upstream superstation (grasslands), 13.95% over the middle stream superstation (croplands), and 11.63% over the downstream superstation (mixed forests), where the overall relative error was 11.64% with an overall rmse of 29.36 W/m² in the study area. The regional distribution of net radiation over the versatile land surfaces was validated well at a large scale during the five-month period and over different land surfaces. It was also observed that the spatial pattern of net radiation varies spatially over three different landscape regions during four different days of the year, which might be associated with different climatic conditions and landscape features in these regions. The overall findings of this study concluded that satellite-derived net radiation can rationally be obtained using a single-source remote sensing model over different land surfaces. Full article

(This article belongs to the Special Issue Radiative Transfer in the Earth Atmosphere)

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