Revisiting Lightning Activity and Parameterization Using Geostationary Satellite Observations

Round 1

Reviewer 1 Report

In this paper, GLM lightning data and ABI cloud data from the GOES-16 satellite observations over the United States from May to September 2020 are used to examine relationships between cloud properties (i.e., cloud top height (CTH) and infrared brightness temperature) and lightning properties (i.e., FED, MFA, TOE) over land, ocean and coastal regions. Cloud-top updraft velocity is also estimated. The authors study the characteristics of the relationships between these observed properties, and fit flash rate vs. CTH parameterisations and compare them with existing parameterisations. Limitations of the present study and a necessity for further measurements are also highlighted.

Overall, I found the paper quite interesting, not the least because the study has used new satellite measurements of lightning and cloud. I have the following, mostly minor, comments which I suggest the authors to consider:

1.    Fig. 9. In these plots, there needs to be uncertainty bars around the data points presented, together with a discussion.
2.    Line 27. ‘…can produce 2–8 Tg N/yr.’ Add a sentence or two as to why this produced nitrogen is important (i.e., the impact on atmospheric composition and climate etc).
3.    Line 41. I think 55 deg C should be -55 deg C.
4.    Eq. 1. The time interval is taken as 5 min, but the ERA5 data used to calculate the lapse rate would not be available at this fine temporal resolution. How was this addressed – were the ERA5 data interpolated to 5 min?
5.    Fig. 5b does not have a spatial scale. Please add scale and give the grid size detail.
6.    Lines 146, 264. ‘cause’ would be a better word than ‘own.’
7.    Fig. 3c. Are the units flashes/min per grid box? Should it be per 5 min, like in the other figures? Please check.
8.    Fig. 3c. Can this plot be compared with LIS/OTD data? 
9.    Fig. 4. It is not clear to me which are the GEOS data and which are the ENTLN data. Please present and explain better.
10.    Line 175. Replace ‘…between total and CG lightning’ by ‘…between total (as considered here) and CG lightning’.
11.    Line 177. What are the units fJ? Femtojoule? No harm in spelling it out where it first appears.
12.    Figs. 5 and 6. Fig. 5 is essentially a set of scatter plots (not histograms). These figures are a bit confusing to me, and I am not sure if there is a better way of presenting the data. How do you make sure that data points of different colour are not hiding behind visible data points, particularly in Fig 5?
13.    Lines 191. Change to ‘…the height of 12 km in these plots is also the demarcation…’
14.    In the flash-rate parameterisations, sometimes k is termed slope/intercept and sometimes alpha is termed slope, which is obviously inconsistent. I would term k as coefficient and alpha as exponent. Please check throughout the paper and be consistent.
15.    Fig. 10. The ocean colour has changed (from blue to green) in some of the histogram bars. 
16.    Line 282. Give year in the reference cited.
17.    Figs. 7a and 8a. These are not defined in the captions. Also, add spatial scales.
18.    In various figure captions, spell out the terms FED, TOE, TBB, MFA, CTH etc.
19.    The reported analysis has been done for the U.S. The authors should provide a comment as to how this could be extended to the whole globe.

Author Response

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Reviewer 2 Report

Return for major revisions. Please see the attachment.

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