Modeling of Biologically Effective Daily Radiant Exposures over Europe from Space Using SEVIRI Measurements and MERRA-2 Reanalysis
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript provides a model for estimating the biologically effective daily radiation exposure (BEDRE) for each biological process with an analytical formula for its action spectrum. It can be used as an initial validation tool for ground-based UV data, providing good estimates of BEDRE for all biological processes considered. In addition, the model offers a tool to check the quality of UV measurements with biometers and to parameterise the effect of clouds on surface UV. The data, materials, and methodology presented in Section 2 are, for the most part, clearly detailed and well understood, with only a few minor exceptions. The results are well-organized and easy to interpret, while the discussion section is excellently structured, providing a clear and coherent flow of information throughout the presentation.
The manuscript is worth submitting to the Journal because of the importance of the research and the results obtained.
However, I have some comments and recommendations for consideration during the editing of this article, as outlined below. Primarily, I suggest giving more attention to the Introduction section, along with improvements in sentence structure and clarity in the presentation of the material.
Line 10 1) I think it's better to say "a significant impact“ instead of „a profound impact“.
2) You mean "human health" or "ecosystem health"? I would suggest correcting similar to this: „...has a significant impact on both human health and ecosystems.“
Line 11-12 Perhaps it is better to say: "... model is proposed to account for various biological processes“ instead of „... model is proposed for any biological process“.
Line 13 It is more accurate to say: " erythema formation“ instead of „erythema appearance“.
Line 14 “The” BEDRE model …
Line 15 It’s better to say “under cloudless conditions by“ instead of “under a cloudless sky by …”.
Line 16 “The” CMF is an empirical function …
Line 16 “The” CMF is an empirical function …
Line 20 “data” instead of measurements…
Line 21 “The” model provides reliable estimates of BEDRE …
Line 22 “For snow-free conditions” - Under snow-free conditions …
Line 30-33 I recommend improving the readability, flow and clarity of this sentence. For example: “Surface solar ultraviolet (UV) radiation has gained significant attention in recent decades due to its well-documented harmful and beneficial effects on human health. Harmful effects include …, while beneficial effects include …”.
Line 49-70 I recommend that these two paragraphs be expanded and supplemented with more information on satellite instruments (OMI, SEVIRI) and methods for extracting UV data. It is also essential to explain the importance of factors such as cloud cover and the specific biological effects of UV radiation.
For example:
- OMI operates in the ultraviolet-visible (UV-VIS) spectral range at wavelengths from 270 nm to 500 nm, which are essential for UV-related research.
- OMI's surface UV algorithm estimates UV irradiance by correcting for the attenuation effects of ozone, aerosols, surface albedo, and clouds.
- What is erythemal irradiance, maximum sensitivity in the UV-B region (about 297 nm), etc.
- The spectrum of action of previtamin D₃ emphasizes UV-B wavelengths (280-315 nm), etc.
Line 80-82 I recommend improving the clarity and expression of this sentence in English, for example: “We refer to this model as the Universal Biological Effective (UBE) model, as it can directly compute BEDRE values for any biological effect with a known sensitivity to UV radiation."
Line 83-89 My suggestion is to try to improve readability by simplifying the sentence structure and making the content more concise, for example: “The structure of this study ..... Section 2 outlines the materials and methods used, including a description of the European stations that provide UV data and the model developed .... Section 3 presents the results for each biological process, with particular emphasis on validating ... Section 4 ... Section 5 ...“.
Line 91-125 2.1. Ground-based measurements of UV radiation. I recommend that the structure of the provided information be improved by organising the content in a more logical way and by grouping related details together.
For example:
Table 1 presents the ground-based UV-measuring stations considered in this study. The UV datasets from all stations, except Belsk, are available from the World Ozone …. Data from Belsk is available upon request. The UV measurement results should be calibrated by …. UV measurements from Belsk, Reading, Uccle, and Vienna were used to develop the Universal Biological Effective (UBE) model, while data from other stations …
Among the stations, Davos is notable as a mountain station where UV radiation is …
Recently, Belsk’s time series of daily erythemal radiant exposure (ERE) data, which began in 1976, was homogenized. The homogenization procedure … The calibration constants for Belsk’s Kipp & Zonen UV-S-E-T biometer were derived from comparisons …
In Reading, spectral irradiance has been measured since 2004 using ….
The erythemal irradiances measured by the Kipp & Zonen biometer in Vienna ….
For stations equipped with spectral radiometers (e.g., Reading and Uccle), daily ERE values were calculated using … For stations equipped with broad-band Kipp & Zonen biometers (e.g., Belsk, Chisinau, and Davos), erythemally weighted irradiances were recorded ….
Line 131 After 2.2 Ancillary data. For the convenience of readers, it would be better to insert a clarifying sentence on the additional data required for this study. For example:
„The ancillary data required for this study includes total column ozone (TCO₃), clarity index (CI), and satellite UV data for model validation.“
This type of structure logically organizes the Ancillary data and clearly separates the different data sets, making it easier to track the flow of information.
Line 152 Figure 1. Please improve the quality and detail of the figure. It is small and hard to read. This figure is important for this study and it is recommended that the information from it is easy to extract.
Line 200 If you have numbering 2.3.1., you should also have at least 2.3.2. Please consider a small adjustment in the arrangement.
Comments on the Quality of English LanguageThe quality of the English is good. However, the text needs a few minor improvements, some of which I have noted in my recommendations.
Author Response
Reviewer #1
This manuscript provides a model for estimating the biologically effective daily radiation exposure (BEDRE) for each biological process with an analytical formula for its action spectrum. It can be used as an initial validation tool for ground-based UV data, providing good estimates of BEDRE for all biological processes considered. In addition, the model offers a tool to check the quality of UV measurements with biometers and to parameterise the effect of clouds on surface UV. The data, materials, and methodology presented in Section 2 are, for the most part, clearly detailed and well understood, with only a few minor exceptions. The results are well-organized and easy to interpret, while the discussion section is excellently structured, providing a clear and coherent flow of information throughout the presentation.
The manuscript is worth submitting to the Journal because of the importance of the research and the results obtained.
However, I have some comments and recommendations for consideration during the editing of this article, as outlined below. Primarily, I suggest giving more attention to the Introduction section, along with improvements in sentence structure and clarity in the presentation of the material.
Line 10 1) I think it's better to say "a significant impact“ instead of „a profound impact“.
2) You mean "human health" or "ecosystem health"? I would suggest correcting similar to this: „...has a significant impact on both human health and ecosystems.“
The suggested corrections have been made.
Line 11-12 Perhaps it is better to say: "... model is proposed to account for various biological processes“ instead of „... model is proposed for any biological process“.
The suggested corrections have been made.
Line 13 It is more accurate to say: " erythema formation“ instead of „erythema appearance“.
The suggested corrections have been made.
Line 14 “The” BEDRE model …
Line 15 It’s better to say “under cloudless conditions by“ instead of “under a cloudless sky by …”.
Line 16 “The” CMF is an empirical function …
Line 16 “The” CMF is an empirical function …
Line 20 “data” instead of measurements…
Line 21 “The” model provides reliable estimates of BEDRE …
Line 22 “For snow-free conditions” - Under snow-free conditions …
The suggested corrections have been made.
Line 30-33 I recommend improving the readability, flow and clarity of this sentence. For example: “Surface solar ultraviolet (UV) radiation has gained significant attention in recent decades due to its well-documented harmful and beneficial effects on human health. Harmful effects include …, while beneficial effects include …”.
The sentence have been corrected.
Line 49-70 I recommend that these two paragraphs be expanded and supplemented with more information on satellite instruments (OMI, SEVIRI) and methods for extracting UV data. It is also essential to explain the importance of factors such as cloud cover and the specific biological effects of UV radiation.
For example:
- OMI operates in the ultraviolet-visible (UV-VIS) spectral range at wavelengths from 270 nm to 500 nm, which are essential for UV-related research.
- OMI's surface UV algorithm estimates UV irradiance by correcting for the attenuation effects of ozone, aerosols, surface albedo, and clouds.
The suggested sentences have been added to the text.
- What is erythemal irradiance, maximum sensitivity in the UV-B region (about 297 nm), etc.
The following sentence has been added to the text: “Erythemal irradiance is responsible for erythema (sunburn) formation with maximum sensitivity in the UV-B region (about 297 nm).”
- The spectrum of action of previtamin D₃ emphasizes UV-B wavelengths (280-315 nm), etc.
The following sentence has been added to the text: “As with erythema formation, dermal synthesis of previtamin D3 and the process of DNA destruction are the most effective in the UVB wavelength range (290-315 nm).”
Line 80-82 I recommend improving the clarity and expression of this sentence in English, for example: “We refer to this model as the Universal Biological Effective (UBE) model, as it can directly compute BEDRE values for any biological effect with a known sensitivity to UV radiation."
The sentence have been corrected.
Line 83-89 My suggestion is to try to improve readability by simplifying the sentence structure and making the content more concise, for example: “The structure of this study ..... Section 2 outlines the materials and methods used, including a description of the European stations that provide UV data and the model developed .... Section 3 presents the results for each biological process, with particular emphasis on validating ... Section 4 ... Section 5 ...“.
The paragraph have been rearranged to: “The structure of this study is organized as follows. Section 2 outlines the materials and methods used, including a description of the European stations that provide UV data and the model developed to calculate daily radiant exposure (RE) for the selected biological processes. Section 3 presents the results for each biological process, with particular emphasis on validating of the proposed model by comparisons with the BEDRE values from several ground-based UV observing stations in Europe using broadband meters and spectrophotometers. Section 4 contains a discussion. Conclusions are presented in Section 5.”
Line 91-125 2.1. Ground-based measurements of UV radiation. I recommend that the structure of the provided information be improved by organising the content in a more logical way and by grouping related details together.
For example:
Table 1 presents the ground-based UV-measuring stations considered in this study. The UV datasets from all stations, except Belsk, are available from the World Ozone …. Data from Belsk is available upon request. The UV measurement results should be calibrated by …. UV measurements from Belsk, Reading, Uccle, and Vienna were used to develop the Universal Biological Effective (UBE) model, while data from other stations …
Among the stations, Davos is notable as a mountain station where UV radiation is …
Recently, Belsk’s time series of daily erythemal radiant exposure (ERE) data, which began in 1976, was homogenized. The homogenization procedure … The calibration constants for Belsk’s Kipp & Zonen UV-S-E-T biometer were derived from comparisons …
In Reading, spectral irradiance has been measured since 2004 using ….
The erythemal irradiances measured by the Kipp & Zonen biometer in Vienna ….
For stations equipped with spectral radiometers (e.g., Reading and Uccle), daily ERE values were calculated using … For stations equipped with broad-band Kipp & Zonen biometers (e.g., Belsk, Chisinau, and Davos), erythemally weighted irradiances were recorded ….
The paragraph have been rearranged according to Reviewer’s suggestion.
Line 131 After 2.2 Ancillary data. For the convenience of readers, it would be better to insert a clarifying sentence on the additional data required for this study. For example:
„The ancillary data required for this study includes total column ozone (TCO₃), clarity index (CI), and satellite UV data for model validation.“
This type of structure logically organizes the Ancillary data and clearly separates the different data sets, making it easier to track the flow of information.
The suggested sentence has been added to the text.
Line 152 Figure 1. Please improve the quality and detail of the figure. It is small and hard to read. This figure is important for this study and it is recommended that the information from it is easy to extract.
The quality of the image has been improved.
Line 200 If you have numbering 2.3.1., you should also have at least 2.3.2. Please consider a small adjustment in the arrangement.
The numbering have been change, now 2.3.1 is 2.3.2, and 2.3.1. is entitled “Biologically weighted radiant exposures”
Reviewer 2 Report
Comments and Suggestions for AuthorsThis article proposed a biologically effective daily radiant exposure (BEDRE) model to estimate ultraviolet solar radiation at the Earth's surface. The method is well presented, and the results are comprehensive. However, I suggest a few minor revisions or clarifications before considering acceptance for publication.
1. Table 1: I would suggest also include a site location map.
2. Table A1: How were the solar zenith angles bins selected?
3. The results section is comprehensive. For the validation part (Tables 3, 4, 7, 8), I am very interested in both the relative RMSE (in percentage) and the original error values.
4. Table 6 layout could be improved. Some rows were half-covered.
5. Figures could be improved by higher resolution/DPI as well as larger font sizes in the caption. Some information is hard to tell (especially in Figure 1)
6. Figure A2: Chisinau site validation results look bad. Are there any reasons for that?
Author Response
Reviewer #2
This article proposed a biologically effective daily radiant exposure (BEDRE) model to estimate ultraviolet solar radiation at the Earth's surface. The method is well presented, and the results are comprehensive. However, I suggest a few minor revisions or clarifications before considering acceptance for publication.
- Table 1: I would suggest also include a site location map.
The site location map has been added.
- Table A1: How were the solar zenith angles bins selected?
Solar zenith angles were calculated using astronomic formulas for the whole year (not a gap year) and the minimum SZA in each day was selected.
- The results section is comprehensive. For the validation part (Tables 3, 4, 7, 8), I am very interested in both the relative RMSE (in percentage) and the original error values.
The authors are grateful for this comment.
- Table 6 layout could be improved. Some rows were half-covered.
The layout in the WORD format has been improved.
- Figures could be improved by higher resolution/DPI as well as larger font sizes in the caption. Some information is hard to tell (especially in Figure 1)
The Figure 1 has been changed to higher resolution.
- Figure A2: Chisinau site validation results look bad. Are there any reasons for that?
We believe that it is the result of poorly calibrated instrument in Chisinau, which we highlighted in the section 4: “The need for the calibration of individual station data arises when the differences between the observations and the modelled daily ERE in the model/observations scatter plot differ significantly from the ideal 1-1 line of agreement, as was the case for measurements in Chisinau (Figure A2).”
Reviewer 3 Report
Comments and Suggestions for AuthorsComments and suggestions in the attached file
Comments for author File: 
Comments.pdf
Minor editing of English is suggested
Author Response
Reviewer #3
The manuscript 3205726 entitled “Modelling of biologically effective daily radiant exposures over Europe from space using SEVIRI measurements and MERRA-2 reanalysis” by A. CzerwiÅ„ska and J.KrzyÅ›cin, submitted to Remote Sensing, analyses the performance of abiologically effective daily radiant exposure empirical model trained and validated using radiometric measures from European ground-based UV stations from 2004 to 2023.
Measures used by the authors include World Ozone and Ultraviolet Radiation Data Centref or UV data, MERRA-2 reanalysis for total column ozone and SEVIRI for cloud coverage. The authors say that their model “provides good estimates” for all-sky conditions when the solar zenith angle is less than 45° whilw some problems arise with with snow-covered surfaces. At the end, the bias measurement-model is about ±5% and the standard deviation is about 15% regardless of the biological effect considered.
The findings of the paper could have a beneficial impact for scientific and human health purposes. The manuscript is well-organized and references are up to date. Additionally, the English language used in the paper is good.
Generally speaking, I think that the authors should highlight the pros and cons of the model they propose. I have some questions for them that could help:
1) The paper is validated using several stations, as presented in the tables and graphs: how do the authors calculate the 5% bias and the 15% standard deviation?
The bias is a mean difference between model and measurement, i.e. 100%*(xobs-xmod)/xobs, while standard deviation is a standard deviation of the differences between model and measurement.
2) Who could be the potential users of the model? Which is the uncertainty such users need?
This explanation has been added in the Section 4 (discussion):
“Potential users of the model are scientists involved in studying long-term changes in UV radiation associated with climate change. Possible areas of interest could be the identification of sources of UV changes (i.e. estimating the contribution of TCO3, clouds and aerosols to long-term changes in surface UV radiation) and the search for regional changes in UV intensity to delineate ‘hot spots’ with abnormal UV levels. It is expected that knowledge of UV radiation for any location (in the MSG area) will be valuable for those looking for health and environmental impacts of UV radiation. In this way, a kind of balance between harmful and beneficial UV effects on health and the environment can be established in locations where no ground-based UV observations are made.”
3) Does the model need to be calibrated for each location?
We clarified in conclusions (Section 5) that “The proposed model allows estimating the biologically effective daily radiation exposure for any location in the MSG area for any biological effect with a known formula for its action spectrum without validation for each new location.”.
4) In case of positive answer to question 2), does the model need a long time series of UV data for the site of application? That could be a limitation for this type of models.
5) In case of negative answer to the question 2), what is the uncertainty a potential user should expect for a different location?
A potential user should expect a deviation of a few per cent and a standard deviation of about 15% for the biologically effective radiation exposure estimates for other location when the ground is snow-free. Such a statement appeared in abstract and in conclusions.
6) There is an extensive use of acronyms in the manuscript, not always clear (BEDRE becomes ERE and then RE in line 460). I suggest to check the acronyms and to add a table of acronyms at the end to help the readers.
The abovementioned sentence has been corrected and erythemal RE has been changed to ERE. BEDRE means biologically effective daily radiant exposure, ERE means erythemal radiant exposure, and RE means radiant exposure. Abbreviations are defined when used for the first time which is in line with instructions for authors of this journal.
7) The sentence between lines 80-82 is not easy to understand.
The sentence has been changed to: “We refer to this model as the Universal Biological Effective (UBE) model, as it can directly compute BEDRE values for any biological effect with a known sensitivity to UV radiation.”
