Spectral Aerosol Radiative Forcing and Efficiency of the La Palma Volcanic Plume over the Izaña Observatory

Round 1

Reviewer 1 Report (New Reviewer)

Comments for author File: Comments.pdf

Author Response

Please find enclosed the response to Referee #1.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

This paper investigates the aerosol radiative forcing with spectrally resolved observations of a volcanic event.  During the eruption period, there was also a dust storm. Therefore, a study of radiation forcing for two types of aerosols and their mixer is reported here.  As the authors said there is limited data on extended and continuous spectral coverage of aerosol forcing due to limited availability of instrumental setup while most studies are based on measurements of broadband radiometers such as sunphotometers for most monitoring stations.  The study for the identification of two different type of aerosols during the same period is very interesting but can be improved by a few modifications.  There are a few questions that this reviewer would like to understand.

 

1. Literature reviews are needed for forcing data for comparison of past volcanic eruptions or dust events which are mostly broad band measurements of radiative forcing or heating effects. Since this volcano is with VEI 3 which is small but in the past 20 years there have been many moderate volcanic eruptions which affect the environment, stratospheric aerosols, and maybe global climate. In this paper, the spectrally resolved data are new but hard to see their significance without comparison with volcanoes of higher VEI  which were only given by broadband data.

 

2.Africa is also an important source of biomass aerosols. Is there any possibility of arrival biomass aerosols during the observation periods?

3. Problems related to the plots

Many figures in this paper are presented without efficient disposing.  There are a lot of white spaces while useful data are displayed in restricted regions and are hard to see in detail. For example in Figs.(2a,2b,3ab, 4ab) have too much white spaces.  Fig. (6a- 6c): the particle size distributions are congested curves while 3/4 of the frame are white spaces.

Also the dust and volcanic data are plotted with blue/black which is hard to distinguish. It may be better to plot dust with yellow color. 

4. Fig.2a: Is the trajectory at 500-600 hPa (yellow line) indicating the air from the east in the Atlantic instead of Africa?

 5. Questions in section 4

6. Line 362-364: . The ∆F_{E f f} ranges between -2.0 and -2.5 Wm⁻²nm⁻¹AOD⁻¹ for mineral dust, between -1.8 and -2.4 … and -1.7 and-2.4....

These data are for SZA of 30^o . Would you comment on the condition of direct sun? Is the difference going to diminish? 

7.   In Fig. 7-g, the spectrum of AOD is provided. While the solar radiation is not measured at 300 nm due to instrument limitations as shown in DNI (Fig 7a). Then how can you determine the AOD at 300 nm and the vicinity wavelengths?

 8. Section 4.3 and Fig. 7/8: can you compare DF of three cases with other volcanic data such as Pinatubo or the Iceland volcano Eyjafjallajökull in 2010 which are extensively investigated by integrating the spectral DF over all wavelengths? Since most of the literature data are integrated radiative forcing.

 9. In Fig (9beh) For the solar angle dependence, why is the 440,500 nm for dust and volcano with so many structures while the DNI’s are smooth?

 11. line 414-416:

The maximum HR is found at λ< 600 nm. The highest values HR are found for the dust event, whilst the lowest values are observed for the volcanic aerosols….

Question: Can you provide the imaginary parts of the index of refraction for dust and volcanic aerosols to support these statements?

 

Author Response

Please find enclosed the response to Referee #2.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report (New Reviewer)

 

The sentence in lines 13-15 in the Abstract does not seem well-built (a verb is missing and even adding a verb the meaning is unclear, as the Authors mention only SZA 40°-50°, but in the rest of the manuscript they focus on SZA=30°), it is totally unclear to me what exactly the sentence means. It is important that the Authors ckarify this sentence, since it is the main conclusion of the paper. Apart from that, all my concerns have been addressed.

 

Author Response

Thank for your comment, this sentence has been modified as follows:

“…Despite ΔF for volcanic aerosols being greater than for dust events (associated to the larger aerosol load present), the ΔFeff has been found to be lower. The spectral ΔF^eff values, at 440 nm, range between -1.9 and -2.6 Wm⁻²nm⁻¹AOD⁻¹ for mineral dust and mixed volcanic and dust particles, and between -1.6 and -3.3 Wm−2nm⁻¹AOD⁻¹ for volcanic aerosols, considering the solar zenith angles between 30⁰ and 70⁰, respectively.”

 

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The manuscript presents the optical and micro-physical aerosol properties, the spectral radiative forcing, the efficiency and the heating rate associated with the three events during the eruption of Cumbre Vieja volcano at the La Palma Island. This research is certainly interesting and meaningful for the community to understand the aerosol radiative effect as well as regional air quality and climate induced by volcano plume. Overall, the paper is logically structured, but the novelty of the manuscript is not very significant in my view. Also, some details on methods and data need to add to facilitate the understanding of the results. Thereby, I suggest a major revision before the paper can be accepted by Remote Sensing. My detailed comments are listed below.

Major comments

1. I found it difficult to assess the novelty of this manuscript. The methods and the results present in this study are very similar to the previous studies, as mentioned by authors many times in the results part of this manuscript, so what do we learn new from this work? The authors claimed that the studies on spectral radiative forcing are scarce, then it is better to explain why the spectral radiative forcing is more important than that of widely-studied averaged aerosol forcing.

 

2. The second concern is about the missing information on calculating aerosol radiative forcing. The radiation under aerosol-free conditions is the key to the computation of aerosol radiative forcing. Due to lack of the observation,  the authors employ the LibRadtran radiative transfer model to estimate it. Then the model input parameters are crucial to accurately simulate the radiation flux. However, the authors fail to present the detailed model input parameters and the verification of the model calculation, which makes the reader difficult to duplicate the results and check the reliability of the model estimations.

 

 

Specific comments

1.      Line 20. Please give the full name of UTC when it appeared for the first time.

2.      Lines 33. Give the full name of a.s.l.

3.      Lines 67-68. You need to emphasize the importance of the spectral radiative forcing.

4.      Lines 278, 302. It seems the section number is not added in this draft.

5.      Lines 292, R_eff is in different formats in Figure 4 and here, please keep consistent.

6.      Lines 322-323. “Despite the measured spectral DNI and subsequent radiative forcing of volcanic aerosols being higher than the pure and mixed dust particles……”. This description is not true for DNI (Figure 5a) and for near-IR spectral (Figure 5f, i).

7.      Figure 2, the symbol “(c)” is missing in Figure 2c.

8.      Section 3.4. This part is unnecessary in my view, since you did not mention any words in the introduction. I do not know what the key point the authors want to make.

Author Response

Please find the response to Referee #1 in the attached document.

Author Response File: Author Response.pdf

Reviewer 2 Report

This work presents the estimation of the spectral direct radiative forcing and efficiency from solar measurements at the Izaña Observatory. The author listed three classic cases to discuss the effect of different types of aerosol on Izaña Observatory. I recommend this paper for revision as per following concerns:

 

Comments :

1.  Line 46-47: “ Radiative forcing due to aerosols is shown to be a key factor in the understanding of climate change ”, rewrite this sentence.

2.  Line 49: What is the net cooling?

3.  Line 54: “ materials and particles ”. What exactly does material refer to? Does it include particles?

4.  Line 59,62,63,68: for example, “ [17], [18], [19], [20]….”. In a manuscript, can a number representing a reference be used as the subject of a sentence? There are many similar unreasonable situations in the manuscript, please revise them carefully.

5.  Line 79-84: “During the eruption, IZO, located only ∼140 km from the volcano, was affected by several events of different types of aerosols of which three have been studied: two events with the dominance of one aerosol type, one affected exclusively by volcanic aerosols and another one affected only by Saharan mineral dust, and a third event affected by a mixture of volcanic aerosols and Saharan dust.”. What function does this sentence serve in this paragraph?

6.  In the manuscript, the layout and display effect of the layer in Figure 2 is not ideal. It is suggested that Figure 2 be separated according to the description of the case and then corresponding one by one, which is simple and convenient.

7.  The summary section should give a more concise description rather than describing the outcome of each case. For example, readers want to quickly judge the differences between cases from this manuscript.

Author Response

Please find the response to Referee #2 in the attached document.

Author Response File: Author Response.pdf

Reviewer 3 Report

 

Review of the manuscript “Spectral aerosol radiative forcing and efficiency of the La Palma volcanic plume over the Izaña Observatory”

 

Dear Editor, dear Authors,

 

The manuscript “Spectral aerosol radiative forcing and efficiency of the La Palma volcanic plume over the Izaña Observatory” describes a set of aerosol and surface radiation remote-sensing observations at Izana Observatory, with the aim of characterising the volcanic plume associated to La Palma eruption of September-December 2021. The Authors classify the airmasses overpassing the observatory as dominated by volcanic aerosol, dust or a combination of both. The topic is certainly of interest for the Remote Sensing readership. A number of original measurements, basically a LiDAR aerosol characterisation and surface radiative fluxes, are supported by AERONET observations and back-trajectories (these further datasets are freely distributed) and have a potential towards an interesting study. Unfortunately, the manuscript has a number of severe flaws so that I can only recommend its rejection in the present form and encourage the Authors to tackle the following major and minor comments before resubmitting a completely revised manuscript. I’m sorry if I cannot be more positive this time.

 

My best regards

 

Major Comments

 

1) The overarching and pervasive problems with this paper are a) it’s general organisation and b) the quality of English language. Specific points about these two issues are in the Specific Comments section.

a) The manuscript seems organised more as a PhD thesis than a scientific paper. A lot of basic introduction and obvious results is given and must be reduced systematically. The text is extremely prolix, many sections are very verbose. In many cases, the information is repeated (see the case of Figs. 5 and 6). It looks like a measurements report has been directly transposed here as a scientific paper but this does not work, in general: the necessary work of synthesis of the available information is clearly lacking throughout the whole paper.

b) The level of the language is largely not sufficient for a scientific paper. The text is very involuted and quite clumsy almost throughout the whole manuscript. Thus, a lot of the text is obscure, difficult to understand. There are also many clear errors in English, which are quite evident even for a non-native English speaker like me. This requires a serious rewriting of the manuscript, with possibly the help of a native English speaker. I have tried to give some guidelines but this falls largely outside the scopes of a scientific review, so I have only made this for the Introduction section – less systematically for the other sections. See Specific Comments.

2) Most specific literature is lacking, especially about radiative forcing estimations for volcanic plumes and Saharan dust. There is now a large literature on both but this is lacking in this manuscript

3) The terminology is quite systematically wrong and many definitions are basically wrong. Also for this point, please see the Specific Comments section of my review.

4) Going to the scientific content of the manuscript, I have serious reservations on the aerosol classifications for the three cases at the basis of the study (volcanic, dust and volcanic+dust). It is not quite OK taking only the position of the point observations in the AOD/AE space to assign airmasses to one or another aerosol type dominance. Here this information layer is ideally coupled with back-trajectories but these latter are scarcely useful if used like it is the case in this manuscript – we just know where the airmasses come from a small-scale perspective but it is scarcely convincing if the larger scale is not also studied. Also, for which altitude are these back-trajectories calculated – there is almost no vertical information on that? If the aerosol classification is not convincing, all the following analyses are quite dubious as well.

5) In the surface radiative forcing (RF) definition, the downward flux only is considered. What about the upward radiation flux, linked to surface reflectivity? With this information lacking, it is hard to judge if results are reliable.

6) The definition of the heating rate (HR) looks like wrong to me. The HR is a wavelength-integrated parameter, accounting for the diabatic heating (or cooling) of the atmosphere due to the interaction with radiation. How can this be shown at two different wavelengths?    

 

Specific Comments

 

1) Page 1 Line 1, “the eruption”: Is it "the" only known La Palma eruption? Otherwise rephrase.

 

2) Page 1 Line 2: Suppress "From a scientific perspective"

 

3) Page 1 Line 3: Suppress "In this contex"

 

4) Page 1 Line 4: "solar *radiation* measurements"?

 

5) Page 1 Line 6: What do you mean with "was affected"?

 

6) Page 1 Line 8, “optical…information”: What specific information? Which measurements?

 

7) Page 1 Line 8: of-->for

 

8) Page 1 Line 9, “(associated…present)”: What do you mean here? "Due to the larger aerosol optical depth for volcanic aerosols wrt dust" or something similar?

 

9) Page 1 Line 9: “*its* DeltaFeff”?

 

10) Page 1 Lines 10-12: How do you compare the different cases if the DeltaF and DeltaFeff are reported here for different cases?

 

11) Page 1 Line 13: further-->a larger?

 

12) Page 1 Lines 14-15: What do you point at with "the latter"?

 

13) Page 1 L19: "The" or "An eruption"?

 

14) Page 1 L22: What do you mean with "materials"?

 

15) Page 1 L25: remove “of the eruption influence” <-- example of redundant text, there is much of it throughout the text, please try to get rid of

 

16) Page 1 L26: remove "conditions"

 

17) Page 1 L27: "having to" is not correctly used here

 

18) Page 1 L29: "enormous" is very informal, please rephrase the sentence

 

19) Page 1 L29: "horizontal and vertical distributions" of what?

 

20) Page 1 L30-32: This sentence is very clumsy, please rephrase

 

21) Page 2 L33-34, “which occurred…eruption”: simplify the sentence to "a few hours before..." <-- an example of very involuted sentence, please correct throughout the text, reduce the verbosity of the whole text

 

22) Page 2 L34, “characteristic”: Do you mean "average"?

 

23) Page 2 L35: remove "for example"

 

24) Page 2 L36, “sporadically”: it is not important that these aerosols are present “sporadically” in that region but that they are present during the activity. Please rephrase

 

25) Page 2 L41: Remove "from a scientific point of view"

 

26) Page 2 L42-45: This is an extremely long sentence, please cut the sentence into two and/or rephrase, otherwise it would impossible to understand for most readers

 

27) Page 2 L46: "compare" with what?

 

28) Page 2 L47: the use of the word "basic" is not correct here

 

29) Page 2 L48, “It introduces…”: What "introduces"? And also, "great"-->"large"

 

30) Page 2 L48: What do you mean with "general"? "global"?

 

31) Page 2 L49: "Scenario" is misleading here. It suggests more the climate projection inputs than the outputs. Please correct.

 

32) Page 2 L49: Ref. 9 is a very general reference, please use more specific references ("and references therein" is not acceptable, you have hundreds of references there, which one is suggested to the reader?)

 

33) Page 2 L50: Is "net" really needed here?

 

34) Page 2 L52-53: This sentence points at the cause of HR variability while it looks like you want to point at consequences (effect on aerosol-cloud interactions). Also, "magnitude" is not correctly used here. You mean "parameter"? Also, what about HR-dynamics interactions?

 

35) Page 2 L54, "tending": you might mean "with the tendency to..."

 

36) Page 2 L55-56: From the sentence it looks like you say "...gases ... and solid ...particles", you obviously don't want to say "gases particles" so please rephrase. Also, what about liquid particles (sulphate aerosols, liquid water)? Sulphate aerosol is the most important source of volcanic forcing to climate and here is not even mentioned! Also, gases are not cooling in particular the climate system, imagine for CO2: Please rephrase to eliminate this ambiguity. 

 

37) Page 2 L57: What do you mean with "climate-model"? “climate model”?

 

38) Page 2 L58-59: Climate impacts for many volcanoes are studied also for persistent passive degassing conditions. Why this is not mentioned here?

 

39) Page 2 L58, “on regional scale”: You mean just "regional-scale studies"? There are a few, why not mentioning it? E.g. see for Etna: https://www.nature.com/articles/s41598-020-71635-1, and for other volcanoes as well.

 

40) Page 2 L59-60, “as well as…active volcanoes”: Of course, this is not true for many volcanoes: Etna, Masaya, even La Palma...

 

41) Page 2 L62, “they intrinsically…parameters”: What do you mean? Be more specific

 

42) Page 2 L63, “virtually all physical and biological systems”: you just mean "the biosphere"?

 

43) Page 2 L64: Suppress "that is...received", all this is redundant

 

44) Page 2 L66-67: This is a clear example of very involute sentence. Why not just "To quantitatively evaluate climate models spectral observations can be used."?

 

45) Page 2 L67-69: This is absolutely obscure to me in terms of text.

 

46) Page 2 L71-72, “The study...has an impact”: What actually has an impact on air quality? In addition, how air quality has an impact on regional climate? These are two different topics, just with possible interactions.

 

47) Page 2 L74-75: "varying spectral irradiance has different impacts" --> "spectral irradiance variability has an impact on". Change all occurrences of "variation" to "variability" throughout the manuscript

 

48) Page 2 L74: "[20] showed"--> "Dirnberger et al. [20] showed" (this latter is the right way to use refs when they are the subject in a sentence, please check throughout the manuscript and modify all occurrences of bad use)

 

49) Page 2 L75-76: What is "mainly driven..."?

 

50) Page 2 L78, “geosphere”: It’s better to use "surface"?

 

51) Page 2 L79-83: Split this huge sentence into two. Also, there are many studies e.g. at Lampedusa observatory that should be cited here. Also see for volcanoes what has been done at Etna (e.g. https://www.sciencedirect.com/science/article/pii/S1352231018301924). Why are you completely ignoring radiative modelling and observations/modelling hybrid methodological studies (e.g. at Etna, many studies by Salerno and Sellitto). Honestly, there is a lot of literature that here is simply ignored and this is a major flaw of the manuscript.

 

52) Page 2 L84-85: The sentence is very clumsy and please don't use such informal words like "enormous"

 

53) Page 2 L86-87: What do you mean with "complex"? Which is the complexity? Please simplify the language throughout as well

 

54) Page 3 L96, “among them”: "including"?

 

55) Page 3 L99, “Izana Observatory”: "IZO"? Here and elsewhere, once an acronym is introduced please use it systematically.

 

56) Page 3 L103, “two events…type”: Is this sentence necessary? Why not starting directly with "one event affected by volcanic aerosols..."

 

57) Page 3 L106, “divided”: "organised"?

 

58) I have quite extensively commented the text for the Introduction but I stop here. For the next sections, please try to improve systematically the text possibly with the help of a native English speaker

 

59) Page 5 L205: In your definition, this is not just the "radiative forcing" but the "surface radiative forcing" (e.g. opposed to "top-of-atmosphere radiative forcing" which also is an important climate parameter)

 

60) Page 5-6, Eq. 1: So the RF is just calculated using downward radiation. This looks like partly wrong, as it does not consider the upward radiation flux, associated with surface reflectance. In case of highly reflective surfaces, this can be important. Please solve this issue.

 

61) Page 6 L210, “spectral”: Why this is "spectral" while the radiative forcing at L205 is not defined as "spectral" (in fact it is)

 

62) Page 6 L214: Something missing in “Eff”   

 

63) Page 6 L220-222: Which is the spectral resolution of REPTRAN used here? This can be chosen in LibRadtran and the choice must be mentioned here

 

64) Page 6: Did you actually apply Eq. 4 or rather you just got LibRadtran HR outputs – which are available as an output?

 

65) Page 6 L234-235: Why the LibRadtran inputs are listed here and not before, when discussing the RF?

 

66) Fig. 2 and all figures: Increase size of all labels in all figures.

 

67) Page 8, Fig. 2: What is the meaning of the red arrow?

 

68) Page 8 Fig. 2: Panel c is practically near useless as it is not possible to see where the back-trajectories come from and also the map is not clear without a larger context. Where is the volcano? Where is the Saharan desert? Which is the altitude of the back-trajectories?

 

69) Page 8 L247-250: Please make shorter and less involuted sentences.

 

70) Page 8 L263, “probably”: How are you sure of this, so to say "probably"? How do you sort this out with respect to e.g. dust?

 

71) Page 8 L254-255: Where is the size distribution information?

 

72) Page 8 L256, ref. 67: This is for a different volcano and extremely different atmospheric conditions, how can you just compare the two directly?

 

73) Page 8 L258, “0.01”: you mean 1%? Please use either % or "0.X" notation

 

74) Page 8 L259-261: How do you understand this form the tiny part of trajectory visible in Fig. 2c? Please bring more convincing elements for the aerosol type attribution otherwise all subsequent results are basically invalidated.

 

75) Page 9 L262-263: Please show a larger scale evidence of Saharan dust transport. As it stands, this attribution to Saharan dust is quite unconvincing.

 

76) Page 9 Fig. 3c and text at L266-267: This looks like exactly the same as Fig. 2c. Is there an error?

 

77) Page 9 L267-269, “These homogeneous…profiles”: Where can you see this?

 

78) Page 9 L271: What do you mean with "a combination of the two previous cases"?

 

79) Page 9 L272-273: What do you mean with "carried on the SAL"?

 

80) Page 9 L273-274: There is no Fig. 4i and no Fig. 4l!

 

81) Page 9 L274: "from 1.8 km" to...?

 

82) Page 9 L276-278: I cannot see at all the second volcanic layer

 

83) Page 10 L283: Here you are talking about the AERONET photometer?

 

84) Page 10 L 287: There are specific volcanic applications of the study of the AOD/AE space. Please use pertinent literature, refs. 70 and 71 are very generic (is there such a study btw in ref. 70 at all?)

 

85) Page 10 L287, “These studies”: Your studies? Or those in ref. 70-71?

 

86) Page 10 L288-289: What is background if you have dust and volcanic complementary in terms of AOD and AE?

 

87) Page 10 L289-293: The categorisation of the plumes are given based only on raw optical properties (AOD and AE). For this reason, it makes no sense to tag these as "pure" or "almost pure". More evidence for aerosol type attribution must be given and this sentence must be rephrased more cautiously in any case.

 

88) Page 10 L297: "compared" to what?

 

89) Page 10 L298: what do you mean with "at the reference"?

 

90) Page 10 L299, “confirm”: This might be an indication but by no means a "confirmation"

 

91) Page 10 L303-305: This is quite a strong contradiction with literature: usually, volcanic aerosols, especially if composed of thin sulphate aerosol component, have smaller AODs wrt dust.

 

92) Page 10 L306-310: All this is obvious because the spectral variability of the AOD is linked by definition with the AE. All this part can be suppressed

 

93) Page 10 L307, “ranging from 0.05 to 0.29”: As a function of what?

 

94) Page 10 L309, ref. 67: Again, this is for a very different volcano/environment

 

95) Page 11 L316-on: At this point, this looks like more a measurement report or a thesis than a scientific paper. Fig. 5 and 6 contents are redundant. The AE, fine/coarse mode AOD ratio and size distribution all carry the same information. The Authors should really work more towards synthesis. For this reason, I won't correct anymore from L316 to 338.

 

96) Page 12 L349-350, “which, moreover…considered”: Isn't it obvious?

 

97) Page 12 L354: What do you mean with "extinction capability"?

 

98) Page 12 L355-356: Haven't you affirmed the exact opposite before? This is extremely confusing

 

99) Page 13 L358-359: Isn't it just obvious because of the typical shortwave atmospheric variability (i.e. no radiation under 300 nm, then increasing towards the visible and then decreasing again in the near infrared)? Please get rid of all obvious evidences.

 

100) Page 13 L359-360: Apart from the extremely clumsy language, where do you see in Fig. 5 that the maximum radiative forcing is expected to be in the visible range?

 

101) Page 13 L363: What do you mean with "intensity wavelength"?

 

102) Page 13 L364-365: Is it visible from Fig. 5b? It does not look like so

 

103) Page 13 L365-372: All this discussion on RF spectral variability is extremely obscure

 

104) Page 13 L373-378: Can you really see all this from Fig. 7c?

 

105) Page 15 L385-387: The RF and efficiency are not decreasing with SZA, on the contrary they are increasing (even if they are negative, their norm increases)! And this also is a quite well known and normal behaviour of the shortwave atmospheric radiation (as also mentioned at L388-389, btw: this depends mainly on the radiative transfer geometry and not primarily on multiple scattering even if this adds up), and as such an obvious result to be avoided in a scientific paper

 

106) Page 15 L394-396: How is this estimated?

 

107) Page 15 L408-410: Isn't it evident?

 

108) Page 15 L412, “has no a minor impact”: Please revise English language

 

109) Page 15 L417-421: All these results are for quite ashy plumes. Why your results are not compared with more sulphate-containing plumes, as it looks like La Palma plume from your previous discussion? See e.g. https://acp.copernicus.org/articles/16/6841/2016/ (btw your RFE are quite different from those found in previous literature, which must be justified)

 

110) Page 15 L422-423: Why not comparing with Saharan dust itself, see the many works of the Lampedusa observatory staff (e.g. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2009JD012697 and others)

 

111) Page 16 L427-430: I don't get why you stress this point

 

112) Page 16 L432-433: Please revise the HR definition. This is not quite correct.

 

113) Page 16 L435-436: Please rephrase this to point at the exact day and time of the measurements. The attribution to one or another aerosol typology is not intrinsic to the measurement but one of your results (and one of my major revisions).

 

114) Page 16 L438-439: These are three different volcanic plumes? Please be more precise

 

115) Page 16 L440-441: I don't get it at all. The HR is a spectrally-integrated parameter, how this can be shown at different wavelengths in Fig. 9b? This issue applies to the whole subsequent discussion

 

116) Page 16 L449-454: What is the physical meaning of an integrated HR? It is supposed to be a vertical profile parameter, pointing at localised vertical impacts so what is the meaning of a “HR integrated column”?

 

117) Page 17: Due to the substantial flaws of the manuscript, I'm not commenting on the Conclusions but I recommend to modify them based on the proposed modifications for the overall manuscript

Round 2

Reviewer 1 Report

My comments have been addressed appropriately in the revised version. However, I have several minor comments that have emerged during the review of the revised version.

1. lines 351-352. The radiative forcing of volcanic aerosols is lower than that of the pure and mixed dust particles for wavelength > 700 nm.

2. lines 477. "the F reaches" should be "the ΔF reaches".

3. As suggested by Reviewer 2, the descriptions of each case in section 4 should be removed, since you give a more concise description.

 

Author Response

The answer can be found in the attached document.

Author Response File: Author Response.pdf