Water Vapor Retrievals from Spectral Direct Irradiance Measured with an EKO MS-711 Spectroradiometer—Intercomparison with Other Techniques
, Emilio Cuevas 2,*, Victoria Eugenia Cachorro 1, Omaira E. García 2, África Barreto 2, A. Fernando Almansa 1,2,3, Pedro M. Romero-Campos 2, Ramón Ramos 2, Mário Pó 4, Kees Hoogendijk 4 and Jochen Gross 5Round 1
Reviewer 1 Report
The work Garcia et al. is very interesting and fits the themes of the journal. A method is developed to retrieve PWV from an EKO spectroradiometer, benefiting from the spectral measurements. Uncertainties are quantified in a robust way. Retrievals are compared with other independent methods and are in a good shape. This work is important in the ongoing task to exploit spectral solar measurements which are performed more widely every year, in a prospect of replacing filter radiometers in the future. Thus, I suggest to accept the manuscript for publication, after undertaking some minor revisions.
L44-54 It is important to highlight that MWP and radiosondes provide profiles of water vapor in the atmosphere, which is then integrated to PWV. Thus, they have a more detailed information compared to sunphotometric and GPS retrievals. I think this is important to keep in mind when comparing the retrievals and evaluating the methods.
L59-67 I think it also important to group the studies referred and the methods according to filter radiometers-single band retrievals and spectroradiometers-spectral retrievals.
Line 81 de cost the cost
L207 The spectral region 930-960nm seems to be the more affected from the PWV. But I think it is useful to investigate the exact boundaries that produce the most robust retrievals. See the work of Raptis et al., 2018
Figure 4 I suggest to add a plot of PWV uncertainty in respect to AOD to better visualize what is described in the manuscript.
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Reviewer 2 Report
REVIEW of the manuscript "Water vapour retrievals from spectral direct irradiance measured with an EKO MS-711 spectroradiometer.Intercomparison with other techniques" by Rosa Delia García, Emilio Cuevas, Victoria Eugenia Cachorro , Omaira E. García, África Barreto, A. Fernando Almansa, Pedro M. Romero-Campos , Ramón Ramos, Mário Pó, Kees Hoogendijk and Jochen Gross [Remote Sens.,2020].
This manuscript deals with an important subject as precipitable water vapor (denoted PWV) retrievals. This study presents the first PWV values measured with an EKO MS-711 grating spectroradiometer from direct normal irradiance (DNI) in the spectral range between 930 and 960 nm at the Izaña Observatory (Spain) between April and December 2019. The expanded uncertainty of was theoretically evaluated using the Monte-Carlo method. The estimated uncertainty presents a clear dependence on PWV. In addition, the EKO PWV retrievals were comprehensively compared against the PWV measurements from several reference techniques available at Izaña Observatory. The EKO PWV values closely align with the abovementioned different techniques. In general, the EKO MS-711 spectroradiometer is precise enough to provide reliable PWV data on a routine basis and, as a result, is able to complement existing ground-based PWV observations.
The manuscript is generally well-written. The main novelty of the study is clearly expressed (especially in Introduction). However, in my opinion, the authors need to make an extra effort to improve their manuscript before eventual publishing in this eminent journal.
Comments
The novelty of investigation must be explicitly emphasized in Abstract and in Summary and Conclusions with significantly fewer abbreviations which sometimes make it difficult to follow the text.
The Monte-Carlo method needs to be present in more details because it is different in each application.
For a wider meteorological community, this is necessary to be also present the quantitative comparison of some PWV results performed by different methods in the sites outside Spain.
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Reviewer 3 Report
Please see attached file for comments.
Comments for author File: Comments.pdf
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Reviewer 4 Report
Please see attached review. Mostly text editing... the methods used by the authors are fine.
Comments for author File: Comments.pdf
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Round 2
Reviewer 2 Report
REVIEW of the revised version of the manuscript "Water vapour retrievals from spectral direct irradiance measured with an EKO MS-711 spectroradiometer.Intercomparison with other techniques" by Rosa Delia García, Emilio Cuevas, Victoria Eugenia Cachorro , Omaira E. García, África Barreto, A. Fernando Almansa, Pedro M. Romero-Campos , Ramón Ramos, Mário Pó, Kees Hoogendijk and Jochen Gross [Remote Sens.,2020].
The revised version of the manuscript is significantly improved compared to the original version. However, in my opinion, some sentences from the Introduction about the advantage of the method may be transferred to abstract and in summary and conclusions because a new instrument does not mean a better method. Some quantitavive indicators outside Spain are not yet present in the manuscript. At the end, I consider that this manuscript must be further revised before eventual publishing in this eminent journal.
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