On the Trend in Below-Cloud Solar Irradiance in The Netherlands versus That in Aerosol Sulfate Concentration
Round 1
Reviewer 1 Report
Review of Crumeyrolle et al submitted to Atmosphere
On the trend in below-cloud solar irradiance in the Netherlands versus that in aerosol sulphate concentration
The study of S. Crumeyrolle, A. Khlystov and H. Ten Brink aims to understand the levers behind the observed increase in below cloud irradiance in the Netherlands. They use an observational dataset which is challenging given the inhomogeneities of it. They took well advantage of the published literature to end up with a trend in CNDC from sparsely sulfates concentration measurements. A trend which explains partly the increase of below cloud irradiance although it seems to not be the unique factor for this high increase.
The manuscript is easy to read and not too lengthy. Sometimes, I feel that some ideas could have been expressed more extensively, I detail some examples in my comments hereafter.
I note that for an observational/experimental approach this study lacks from uncertainties calculations. I would like the authors to add such uncertainties estimates or explain why it is impossible to do so in the future version of the manuscript.
Overall, I recommend this paper for publication in Atmosphere after taking into account some minor issues. I detail these issues hereafter.
Questions, remarks and recommendations related to the text:
Introduction:
- L.43-45: The mention of the US is odd in the first part of the sentence. I would rephrase it. Did we observe a global decrease, if yes: “…and total annual SO2 emissions decreased, [and then keep US and Europe examples and references]”.
- L.82-83: The use of the future tense does not concord with the previously used past tense.
- L.84: A verb is missing in this sentence, “impact”?
Part 2:
- L.92-93: Please detail the acronyms FSSP and MARGA.
- L.96: “for the first time and detailed in the Appendix.”
- Fig.1: Could you provide uncertainties estimates for these time-series?
- L.98: Please, define “IOP”
- L.110-116: Indeed, an offset is clearly visible on the figure 2. The discrepancies are about 100 cm-3 for CDNC, both in figure 2 between the simulation and the B&L parametrization and in table A1 between cloud base and the rest of the cloud. Thus, it is totally coherent, I think it could worse highlight that in a more extensively way, discussing a bit more the process that explain that and provide further references.
- Figure 2: Considering the 100 cm-3 offset, it could worse replot a second bulk of points where we can expect the CDNC for an in-cloud sample.
- Figure 2: could you estimate uncertainties, and plot them?
Part 3:
- L.131: please define XRF
- L.189-192: These two last sentences can move to the conclusion. Moreover, you explain at least a part of the observed below cloud irradiance increase even if your result is about 5-fold lower. Again, adding uncertainty to your result could give the reader a better estimate of the robustness of your findings.
Conclusion:
- L.207-208: It can explain at least a part of that enhancement.
- Could you provide more clues on what could explain this increase? Could this increase be overestimated? Where should research on that topic aim after your results?
Supplementary material / Addendum:
- L.68: suppress “was” before lower
- L.69: west-Europe [] ïƒ western Europe?
- L.70: correct place for “also” would be between “CDNC” and “maximized”
Author Response
Please see attached document
Author Response File: 
Author Response.docx
Reviewer 2 Report
The authors tested Boucher and Lohmann parameterization using cloud chamber measurements of non-sea-salt (nss) sulphate mass concentration and cloud droplet number concentration (CDNC). The topic is of great importance for our community. However, this manuscript is not acceptable for published in Atmosphere at this stage, which should be revised thoroughly before resubmission.
Abstract: Please avoid citing sources in an abstract unless it's absolutely necessary. Your abstract should be self-contained and focused on your research.
Data and method section: Please add a section describing the data and methods you used. Such section is necessary.
Figure 1: The figure size should be the same for panels (a) and (b). For better comparison, curves for sulfate concentrations and CDNC can be emerged into one plot.
Author Response
Please see attached file
Author Response File: Author Response.docx
Reviewer 3 Report
Comments for author File: 
Comments.pdf
Author Response
please see attached document
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
The authors have revised the manuscript thoroughly, and all my concerns are well addressed. It is now acceptbale for pulication.
