Diurnal differences in the effect of aerosols on cloud-to-ground lightning in the Sichuan Basin

Wang, Haichao; Tan, Yongbo; Shi, Zheng; Yang, Ning; Zheng, Tianxue

doi:https://doi.org/10.5194/acp-23-2843-2023

Articles | Volume 23, issue 4

https://doi.org/10.5194/acp-23-2843-2023

© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/acp-23-2843-2023

© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 23, issue 4

Research article

|

02 Mar 2023

Research article |

| 02 Mar 2023

Diurnal differences in the effect of aerosols on cloud-to-ground lightning in the Sichuan Basin

Haichao Wang, Yongbo Tan, Zheng Shi, Ning Yang, and Tianxue Zheng

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Final revised paper (published on 02 Mar 2023)
Supplement to the final revised paper
Preprint (discussion started on 05 Sep 2022)

Interactive discussion

Status: closed

RC1:
'Comment on acp-2022-553', Anonymous Referee #1, 09 Sep 2022

General Comments

This paper is reasonably well written and flow well; however, it does have a few errors and grammatical issues that are addressed below. The paper does a very good job of illustrating day-night contrasts in the effects of aerosols on lightning frequency over the Sichuan Basin. However, the conclusions are qualitative and can be quantified better.

Specific Comments:

L1-2: The title could be clearer. Perhaps “Diurnal differences in the effect of aerosols on Sichuan-Basin lightning”

L60-61: The meaning of this sentence is unclear. Are you saying that aerosol radiative effects counter microphysical effects and make it difficult to confirm the modeling results using observations or something else?

L90: Possible contamination by what? IC flashes? If yes, please say this

L90: Since you only discuss CG flashes in this draft, you might replace all references to CG lightning with lightning – after stating once that lightning flash refers to CG lightning flash.

L91: These 2 sentences are confusing. Is this what you mean? Additionally, only the first stroke is retained if more than one stroke occurs in the next second within the first 10 km of the first stroke as two strokes that occur within 0.5 seconds are assumed to be from the same flash.

L105: You mention 5 factors but discuss 7.

L123-L128: It is unclear how you obtained 564 and later 11408 samples. In addition, the reference to section 3.4 is confusing. Please rephrase this paragraph giving information such as how many grid boxes are in the region of interest? What percent of these grid boxes were excluded by the flash criterion? Also, only mention the 10 flash threshold once in the revised paragraph.

L130: The rectangular study region shown in Figure 1a doesn’t match any of the other study regions shown in the paper. Perhaps remove.

L143: Figure 3 does not show the wind field.

L181: Why do we care about hourly variations in the percentage of positive CG flashes?

L203-204: Warm (cold) colours in the figure mean more (less) … subset. Consider moving this sentence to the caption for Figure 5.

L200-216: Discussion of Figure 5: Could you calculate and show the percent of 0.1 x 0.1 degree grid boxes where the change is positive and also give the mean change (amount and percent) for each of the 8 regions.

L219: You repeatedly refer to Period1 and Period2 over the next several pages. It might be better to replace these terms with morning and middle-of-the-night or something meaningful.

L233-234: It is unclear what you mean by this sentence. Are you saying that you see a 0.3 threshold during the day in this study consistent with other studies? If yes, state this more clearly.

L253-255: Are there any scientific studies of convection in the Sichuan Basin that support this inference? If yes, please reference them.

L256: TCL is negatively ï Be clear as to whether you mean TCLW or TCIW.

L272-276: Check the captions in Figure 9 and make sure TCLW and TCIW are used appropriately. They probably all should be labeled TCLW.

L296: Rather than stating that more CG flashes are found it would be more interesting if you could give a percent increase range by dividing values from a subset of the bins.

L305: Rather than “more marked” cite a percent change. This should be done throughout L296-305.

L357: Hopefully, you can support this inference by other studies.

L591-595: Figure 4 caption does not match Figure 4.

Figure 5: Be sure to use BJT consistently as opposed to BJ

L604: Here and elsewhere consider replacing “ the error was calculated” with “the uncertainty was calculated”

Figures 10 and 11: It might make more sense to show the flash counts with the numbers rather than the number of samples in the cell. This would emphasize your main points and give the reader more interesting numbers to play with.

Technical Corrections:

Abstract_L10: has been involved ð¡ª has been examined

Abstract_L14: on day and night were analyzed ð¡ª were analyzed during both day and night

Abstract_L15: found in the diurnal variation of ground flash ð¡ª found

L1: is a kind of ð¡ª is an

L39: The radiative effects suggest that aerosols can ð¡ª Through radiative effects aerosols

L42: convections ð¡ª convection

L45: aerosols loading ð¡ª aerosol loading

L45: not fixed ð¡ª variable

L49: in affecting ð¡ª to affect

L54: loading conditions. ð¡ª loading conditions, respectively.

L55: under low ð¡ª under both low

L58: elevating ð¡ª increasing

L68: preferential -ï preferentially

L68: but reverse in the afternoon ï but the situation is reversed in the afternoon

L83: were obtained from China ï was obtained from the China

L88: almost all parts ï most

L88: about 80-90% ï 80-90%

L93: calculated at ï aggregated to

L98: last version ï latest version

L133: Intensely anthropogenic ï Intense anthropogenic

L134: the low-pressure system ï the climatological low-pressure system

L135: which is markedly larger ï with markedly larger concentrations

L139:, and the number of CG flashes happens at night, accounting ï accounting

L145: As times goes by, the pattern of this spatial distribution is gradually disappearing. The CG ï By afternoon, the CG

L148: and progressively focused on ï with increasing focus

L158: At late night, a cold ï Late night, cold

L162: have not been comprehensively understood ï are not completely understood

L167: in averaged total ï of total

L167: is first examined under …--. Is first shown for the clean and polluted subset in Fig. 4a.

L172: is most remarkable at night, then in the morning, and the smallestï is largest at night and smallest

L229: more significant than ï greater than

L268: TTCG?

L273: , CC, ï total column cover (CC),

L276: convections in ï convection in

L283: two opposite ï opposite

L285: are the general – elicit the general

L291: following contents, ï following content

L318: Besides, part of aerosols can ï Besides, some aerosols

L355: and reverse at night ï and enhance it at night

L356: afternoon, it ï afternoon, system

L357: it may be overwhelmed by mesoscale ï systems may include many mesoscale

L385: model simulation ï model simulations

L598: unite ï units

Citation: https://doi.org/10.5194/acp-2022-553-RC1
- AC1: 'Reply on RC1', Haichao Wang, 09 Dec 2022
  
  Please find attached.
  
  Citation: https://doi.org/10.5194/acp-2022-553-AC1
RC2:
'Comment on acp-2022-553', Anonymous Referee #2, 25 Sep 2022

Please find attached.

Citation: https://doi.org/10.5194/acp-2022-553-RC2
- AC2: 'Reply on RC2', Haichao Wang, 09 Dec 2022
  
  Please find attached.
  
  Citation: https://doi.org/10.5194/acp-2022-553-AC2
RC3:
'Comment on acp-2022-553', Anonymous Referee #3, 25 Sep 2022

Please find attached.

Citation: https://doi.org/10.5194/acp-2022-553-RC3
- AC3: 'Reply on RC3', Haichao Wang, 09 Dec 2022
  
  Please find attached.
  
  Citation: https://doi.org/10.5194/acp-2022-553-AC3

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload

AR by Haichao Wang on behalf of the Authors (09 Dec 2022) Author's response Author's tracked changes

EF by Polina Shvedko (12 Dec 2022) Manuscript

ED: Referee Nomination & Report Request started (24 Dec 2022) by Zhanqing Li

RR by Anonymous Referee #2 (06 Jan 2023)

RR by Anonymous Referee #3 (09 Jan 2023)

RR by Anonymous Referee #1 (09 Jan 2023)

Suggestions for revision or reasons for rejection

Wang et al.
“Diurnal differences in the effect of aerosol on cloud-to-ground lightning in the Sichuan Basin”

General Comments

Careful English editing is still needed. See the numerous technical comments. The discussion of Figure 10 is hard to follow and full of speculation. Please shorten.

Specific Comments:

L148: This sentence is confusing.
“In addition, within six hours before the start of each sample, the number of grids with CG lightning flashes records in each hour is less than 10% of the entire study region. This is to ensure that thunderstorm is …”

Is this what you mean?

“In addition, days when flashes occur in more than 10% of the study region during any of the six-hours (06-12 UT) preceding the sample period are removed to ensure that thunderstorm activity is …”

L184: You could argue that there is only one peak on clean days too with the peak lasting from 1700-0100 BJT. Do you believe the decrease in flashes between the two small peaks is significant or noise?

Low and Middle SHEAR –For simplicity, it might be best to use 850 to 700 hPa shear for low shear and 500 to 400 hPa shear for middle shear.

L280: “In the afternoon, the relationship between TCLW and T may contain the above two mechanisms, which leads to an insignificant relationship between them”

Is this what you mean?
“In the afternoon, for TCLW < 0.1 kg m-2, the change in T with increases in TCLW is small as both factors are in play”.

L281: At night, the absence”  “At night, for TCLW < 0.1 kg m-2, the absence”

L269-296: This paragraph is difficult to follow. Ideally, it should be re-written – perhaps shortened.

L570: I’m not sure what you mean by “Black lines represent the 1500 m contour line”. Are you simply saying that the 1500 m altitude line is shown to highlight the location of the basin?

Technical Corrections:
L15: “in the rest of the time”  “during the remainder of the day”
L16: “less than about 0.3”  “less than 0.3”
L22: “convection activities”  convection
L42: “Generally, the relationships”  “The relationships”
L43: “Some studies”  “Several studies”
L63: “Under the polluted condition”  Under polluted conditions
L64” “occurrences were delayed in the day”  occurred later in the day”
L66: “These researches”  “These studies”
L90: “removed to eliminate the possible contaminations of intracloud flashes”  removed because many of them may be IC flashes instead”
L91: “if more than one”  “if multiple”
L91: “with 10 km”  “within 10 km”
L92: “seconds assumed to be from the same flashes”  “seconds are assumed to be from the same flash”
L110: “mainly select hourly reanalysis data of five factors”  “select five variables derived from the reanalysis data”
L126: “its terrain of it”  “the altitude of its terrain”
L131: “marked larger”  “markedly larger”
L140-144:  “… value of a sample. We limit the analysis to grid boxes with at least 1 CG flash during a 24-hour period beginning at 1200 BJT”. The sampling period is chosen to begin at 1200 BJT because flash rates are lowest at ~12 BJT (see Figure 2). The averaged AOD …”
L150: “Finally, we got 532 samples”  “This filtering limited the data set to 532 samples”
L162: “gradually strengthened”  “gradually strengthen”
L163: “lightning concentrated”  “lightning is concentrated”
L171: “encountered”  “encounters”
L199: “are almost large” ”are similar”
L200: “less than 1 flashes hour-1 gird-1”  “less than 1 flash hour-1 grid-1”
L213: “next content”  “next section”
L229: character aerosol  “characterize aerosol”
L245: “is different to them”  “differs from those studies”
L251: “the difference in the lightning distribution has no great influence on its relationship with lightning”  the relationship between wind shear and lightning does not vary much between the day- and night- periods”
L273: “and so does the direct radiation effect of aerosols, which has not significant impact on the surface temperature”  “thus direct radiative effects are small and their impact on surface temperatures is minimal
L282: “promotion of surface temperature to” increase in surface temperature with”
L288: “direct impact of”  “direct impact on”
L298: “the weakening effect of aerosols on surface temperature is dissipated”  “the effect of aerosols on surface temperature is minor”
L315: “overlap”  “counter”
L325: “the difference is more obvious in the rest time”  but the difference is significant during the remainder of the period”
L332: “As the AOD is less”  “When the AOD is less”
L339 and L341: “direct radiation”  “direct radiative”
L348: “might apply”  “should apply”
L349: “Moreover,”  “As a caveat,”

L554: “for the period 2010-2018 including the summer months”  for the summer months () of 2010-2018

L602: TCIW and (d, h)  TCIW-T and (d, h)

L603:  “Note that samples are first sorted by the variable on the x-axis and then samples with similar values of the x-variable were averaged …’

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ED: Publish subject to technical corrections (07 Feb 2023) by Zhanqing Li

AR by Haichao Wang on behalf of the Authors (15 Feb 2023) Author's response Manuscript

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Short summary

The effects of aerosols on lightning are complex and still far from understood. We analysed the impacts of aerosols on lightning activity in the Sichuan Basin. Results show that lightning flashes first increase with aerosol loading during all periods and then behave differently (decrease in the afternoon and flatten at night). This suggests that the changes in solar radiation can modulate the aerosol effects on the occurrence and development of convection and lightning activity.