Comparison of the Atmospheric Electric Field from Three Global Stations in 2021
, Tao Chen 1,*, Jiajun Song 4, Shuo Ti 1, Shihan Wang 1,2, Chunlin Cai 1, Wen Li 1,2 and Jing Luo 1
Round 1
Reviewer 1 Report (Previous Reviewer 1)
The authors have improved their submission by adjusting their data so that the curves no longer show zero values which are obvious un-physical. They have also corrected and clarified other items.
They now attribute the differences between the Carnegie curve and the ZH and XAN station observations to large aerosol processes and radon and convection, which is plausible. The RDG data has small radon, and was selected for having small aerosol and convection, and so is much closer to the Carnegie Curve, which also had small aerosol concentration, no radon, and low convection on fair weather days over the ocean.
They could further improve the discussion, as I recommended on my second revision, by noting that Vostok and Concordia stations at high altitudes on an ice sheet have negligible aerosol concentrations, no radon, and no convection except for a few hours around noon in midsummer. The Vostok and Concordia curves agree in diurnal variation with RDG, and would be even better than the RDG and Carnegie Curves to use as a clean, fair-weather reference for the basic diurnal variations due to the global ionospheric potential.
Author Response
Dear Editors and Reviewers:
Thank you for your kind letter of our manuscript (universe-2103013), "Comparison of atmospheric electric field from 3 global stations in 2021" on January 4, 2023. We revised the manuscript in accordance with the reviewers' comments and carefully proofread the manuscript to minimize typographical, grammatical, and bibliographical errors, which are shown in purple. Here, we describe our revision according to the reviewers' comments.
Reviewer #1: The authors have improved their submission by adjusting their data so that the curves no longer show zero values which are obvious un-physical. They have also corrected and clarified other items.
They now attribute the differences between the Carnegie curve and the ZH and XAN station observations to large aerosol processes and radon and convection, which is plausible. The RDG data has small radon, and was selected for having small aerosol and convection, and so is much closer to the Carnegie Curve, which also had small aerosol concentration, no radon, and low convection on fair weather days over the ocean.
They could further improve the discussion, as I recommended on my second revision, by noting that Vostok and Concordia stations at high altitudes on an ice sheet have negligible aerosol concentrations, no radon, and no convection except for a few hours around noon in midsummer. The Vostok and Concordia curves agree in diurnal variation with RDG, and would be even better than the RDG and Carnegie Curves to use as a clean, fair-weather reference for the basic diurnal variations due to the global ionospheric potential.
Response: [We really appreciate you for your positive comments and valuable advice. The discussion has been improved as shown in lines 298-317.]
We tried our best to improve the manuscript and made some changes in the manuscript. We earnestly appreciate the Editors/Reviewers’ work and hope that the corrections will be met with approval. Once again, thank you very much for your comments and suggestions.
Author Response File: 
Author Response.docx
Reviewer 2 Report (New Reviewer)
I feel that this manuscript is not suitable for Universe. On the other hand, it may be suitable for journals like.
The Planetary Science Journal
Planetary and Space Scienc
Earth and Planetary Science Letters (EPSL)
Journal of Geophysical Research D: Atmospheres
Best Wishes for the authors.
Comments for author File: Comments.docx
Author Response
Dear Editors and Reviewers:
Thank you for your kind letter of our manuscript (universe-2103013), "Comparison of atmospheric electric field from 3 global stations in 2021" on January 4, 2023. We revised the manuscript in accordance with the reviewers' comments and carefully proofread the manuscript to minimize typographical, grammatical, and bibliographical errors, which are shown in purple. Here, we describe our revision according to the reviewers' comments.
Reviewer #2: I feel that this manuscript is not suitable for Universe. On the other hand, it may be suitable for journals like.
The Planetary Science Journal Planetary and Space Science Earth and Planetary Science Letters (EPSL) Journal of Geophysical Research D: Atmospheres
Best Wishes for the authors.
Response: [Thank you for your recommendations, this paper belongs to Space Science and the scope of Universe includes it.]
We tried our best to improve the manuscript and made some changes in the manuscript. We earnestly appreciate the Editors/Reviewers’ work and hope that the corrections will be met with approval. Once again, thank you very much for your comments and suggestions.
Author Response File: Author Response.docx
Reviewer 3 Report (New Reviewer)
General comments.
This study compares the atmospheric electric field from 3 global stations in 2021. In general, the manuscript does not match the MDPI template, where there is no method chapter, which makes it difficult to understand how the data was collected and the methodology of this study. In addition, seasonal analysis with only one year's data is also very inadequate.
Specific comments
1. The abstract is not strongly related to the title, where in the abstract there is no visible comparison as stated in the title.
2. Abstract, discussion related to seasons is also very weak because the data is only 1 year; to study seasonal variation requires years of data.
3. Introduction: There is no compelling reason to carry out this research scientifically; the research gap that became the motivation for this research was also not visible. In paragraph 3 several references are mentioned; but there is no elaborated research gap so that in paragraph 4, the motivation for this research is very bland.
4. Definition of fair weather: replace with the Method section and explain the data and methodology. Are the three locations the same method of data collection? The first result section, it should be in the Data and Method Section,
5. Table 3, the amount of data at each station is very different, how does this affect your results?
6. Figure 2-3; add an error bar in the plot.
7. Results: discuss your results better and compare them with related research. Currently, there is very little discussion and analysis.
8. Conclusion and Discussion: Separate these two section, and in the discussion, refer to more references.
Author Response
Dear Editors and Reviewers:
Thank you for your kind letter of our manuscript (universe-2103013), "Comparison of atmospheric electric field from 3 global stations in 2021" on January 4, 2023. We revised the manuscript in accordance with the reviewers' comments and carefully proofread the manuscript to minimize typographical, grammatical, and bibliographical errors, which are shown in purple. Here, we describe our revision according to the reviewers' comments.
Reviewer #3: This study compares the atmospheric electric field from 3 global stations in 2021. In general, the manuscript does not match the MDPI template, where there is no method chapter, which makes it difficult to understand how the data was collected and the methodology of this study. In addition, seasonal analysis with only one year's data is also very inadequate.
Response: [Thank you for your useful comments and we have replaced the third part by “Method”. Since these observations are from different countries and different organizations, and there are differences in their observations. We have selected the year 2021 when their data are all available and complete. There is no way to apply longer period observation data due to the limitation of data.]
Specific comments
- The abstract is not strongly related to the title, where in the abstract there is no visible comparison as stated in the title.
[As shown in lines 20-24, the comparison has been introduced in the abstract.]
- Abstract, discussion related to seasons is also very weak because the data is only 1 year; to study seasonal variation requires years of data.
Response: [Thank you. As shown in the first response, there is no way to apply longer period observation data because these observations are from different countries and different organizations, and there are differences in their observations. Seasonal variations are only part of the subject of this paper, the differences between them, their relationship with PM 2.5 concentrations, and the daily variation of the atmospheric electric field have also revealed in the paper.]
- Introduction: There is no compelling reason to carry out this research scientifically; the research gap that became the motivation for this research was also not visible. In paragraph 3 several references are mentioned; but there is no elaborated research gap so that in paragraph 4, the motivation for this research is very bland.
Response: [Due to the limitations of this research direction, we apologize for not revising it as you suggested.]
- Definition of fair weather: replace with the Method section and explain the data and methodology. Are the three locations the same method of data collection? The first result section, it should be in the Data and Method Section.
Response: [The same method of data collection are same for the three locations.]
- Table 3, the amount of data at each station is very different, how does this affect your results?
Response: [Thank you for your comments. Table 3 are just the statistical results after the definition of fair weather conditions was taken, it can not affect our results.]
- Figure 2-3; add an error bar in the plot.
Response: [Thank you for your detailed comments. This paper is a second submission and the previous reviewer 1's useful comments were opposite to you, he said that the error bars seem unrealistic in view of known convective variability. Considering he is the most knowledgeable and pioneer scientists in atmospheric electricity (from the Academic Editor), so we did not follow this comment.]
- Results: discuss your results better and compare them with related research. Currently, there is very little discussion and analysis.
Response: [Thank you for your suggestions and the discussion has been improved as shown in lines 297-317.]
- Conclusion and Discussion: Separate these two section, and in the discussion, refer to more references.
Response: [Thank you and the Conclusion and Discussion have been separated.]
We tried our best to improve the manuscript and made some changes in the manuscript. We earnestly appreciate the Editors/Reviewers’ work and hope that the corrections will be met with approval. Once again, thank you very much for your comments and suggestions.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report (New Reviewer)
I am sorry. I stand by earlier opinion.
The subject of the manuscript is not appropriate for this journal.
The authors must explore suitable journals.
Best Wishes
Author Response
Thank you for your comments, Universe covers many topics of interest which include “Space Science”. As we all know, “Space Science” is a science subject that includes natural phenomena and laws such as physics, astronomy, chemistry and life that occur in solar-terrestrial space, interplanetary space and the whole universe space. This paper has revealed long term near surface atmospheric electric field observation results, and it’s an important part of the near-surface observation. So we think it belongs to “Space Science”, it belongs to the scope of Universe.
Reviewer 3 Report (New Reviewer)
The author has revised some of the suggestions but has not revised some of them because of some reasons, such as data problems and arguing with another reviewer they saw as more expert in this field. The author's revised points are more about writing and systematics rather than the main suggestions related to seasonal variations. Because only short-period data is available, the author should look for several case studies rather than discuss seasonal or diurnal variations. Short-period data can not be used to analyze seasonal and diurnal variations adequately. Therefore, this manuscript still needs major revision.
Author Response
Thank you again. This paper focuses mainly on the differences in fair weather atmospheric electric field curves at different locations in the globe, and the reasons for their differences, while seasonal variations are secondary. Due to the different time periods of global station data observations, it may take up to 5 years or 10 years later if the study needs more data cases.
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
This submission is an analysis of the diurnal variations of the near surface atmospheric electric field (AEF) at three stations, in the UK, Austria, and China, from January to December 2021. The authors then attempt to separate out the local effects, mainly due to local meteorology, from effects in Universal time, supposedly relevant to all three stations.
Unfortunately, their analysis is flawed by their lack of understanding of the character of global atmospheric electricity, and the separate contributions of the diurnal variation of ionospheric potential (in UTC) and local convection (in LT) to the measured electric field at any one location. This has led them to an erroneous use of the term ‘Carnegie Curve’ and to an approach to analysis that does not yield any new or useful information.
On line 20 they define the “Carnegie Curve” as “The average daily variation curve of the AEF under fair weather conditions”. This is incorrect, and as their reference to Harrison (2013) and other publications should have made clear to them. The Carnegie Curve is the result of AEF measurements made on the ship ”Carnegie” as it sailed the worlds oceans, and as Harrison says “Analysis of the results from CruiseVII confirmed the important result that the daily electric field variation in universal time was independent of the ship’s position.” Over the ocean, there is on average negligible diurnal variation in convection, and the results were selected for fair weather conditions, where essentially the only contribution to the AEF was from the global ionospheric potential, and because this potential variation is global, the AEF values were independent of the ships position.
The diurnal variation of the global ionospheric potential overhead drives a current density downward which creates the observed AEF at any location. In the absence of diurnal variation in convection over the ocean, the diurnal variation in AEF is the same as that of the ionospheric potential, with a maximum near 20h UTC and a minimum near 4h UTC, which is the shape of the “Carnegie Curve”. On line 38 the authors describe the ionospheric potential as approximately 250 kV, evidently without realizing that its diurnal variation is what defines the “Carnegie Curve”. So it is wrong to describe any diurnal variation over land, subject to strong perturbations due to convection, as a “Carnegie Curve” as is done throughout this submission.
It is contrary to accepted atmospheric understanding of atmospheric electricity to say (line 189) that “the Carnegie curves for different regions on earth vary”.
The selection of AEF data only for ‘fair weather’ conditions can remove some, but not all of the local effects, and the AEF data from Reading in Fig 2a bears the most resemblance to the curves obtained on the Carnegie, probably because they have more stringent criteria for fair weather, including the absence of cumuliform clouds signifying convection.
The diurnal curves from the ZH (Chinese)station are strange, and incompatible with expectations. They have zero values for all 57 days at 16 UTC and 18 UTC for Oct-Dec, and all 36 fair weather days at 18 UTC July-Sept. (Negative values were said to be excluded in these averages). In these cases, the error bars indicate zero uncertainty. If these were real AEF values it would be unique in the two centuries of history of atmospheric electricity, and they would deserve a paper all to themselves! The ZH curves also have much higher maximum values than the Reading curves, suggesting strong convection effects near 4h UTC (near noon local time). Attributing the diurnal variations to “geological conditions“ (line 199) is again contrary to accepted atmospheric electricity understanding.
For the XAN (Greek) station, the maximum values are again much higher than expected from the Carnegie curve and the Reading curves, signifying strong convection from 8 to 14 UTC, again in the middle of the day local time. Again, the error bars seem unrealistic in view of known convective variability.
Figure 3 is very misleading in that it describes (lines 200-201) the average of the diurnal variations at the RDG, ZH, and XAN stations as the “total average Carnegie curve”. This description is contrary to accepted understanding of atmospheric electricity. When comparing curves dominated by local effects, one should compare them in LT, not UTC. Then the ZN and XAN stations would have compatible curves, different from the RDG curve because much more stringent criteria were used with the RDG data to eliminate local convective effects.
The authors would do well to compare the results for the three stations with the UTC curves that Harrison (2013) shows for the actual ‘Carnegie’ curves observed over the global oceans, and the diurnal variations observed from Vostok and Concordia Antarctic stations, (Burns et al., 2012, 2017), for the different seasons. The Antarctic measurements were made over the ice plateau at high altitude, with negligible convection except near noon in midsummer, and when corrected for the effects of blowing snow and the solar wind input, give more accurate variations for the diurnal variation of ionospheric potential than from any other station, superseding the shipboard Carnegie measurements, and applying to recent decades rather than to a century ago.
References:
Burns, G. B., Tinsley, B. A., Frank Kamenetsky, A. V., French, W. J. R., Klekocuik, A. R., Monthly global circuit estimates derived from Vostok electric field measurements adjusted for local meteorological and solar wind influences. Journal of the Atmospheric Sciences, 69, 2061–2082. https://doi.org/10.1175/JAS-D-0212.1
Burns, G. B., Frank Kamenetsky, A. V., Tinsley, B. A., French, W. J. R., Grigioni, P., Camporeale, G., & Bering, E. A. (2017). Atmospheric global circuit variations from Vostok and Concordia Electric field measurements. Journal of the Atmospheric Sciences, 74, 783–800. https://doi.org/10.1175/JAS-D-16-0159.1
Author Response
Reviewer #3: The paper presents interesting research on potential gradient variations near the Earth's surface. With some amendments it will be suitable for publication.
Geological conditions are cited as the reason for the form taken by AEF curves at different sites in Figures 2 and 3 (e.g. on L199). Further explanation is required for this attribution, including citations and/or additional data. How are geological conditions different between the sites? Why are atmospheric conditions (like aerosol concentration) not responsible?
Response: [Thank you for your useful advice. Further explanation of the different curves of different regions has been added as in lines 299-314. For the local geological conditions in a certain region, the radon gas content varies in different regions, radon gas undergo decay and emit α particles, which may further ionize the local atmosphere and positively and negatively charged particles are injected close to the surface. This process changes the distribution of spatial charge density and disturbs the AEF value. Therefore, the baseline characteristics of the atmospheric electric field are different in different regions. Aerosol concentration is also a factor and it can be attributed to PM2.5 concentration as in lines 305-310.]
Later aerosol behaviour is described (L213-215). However, no source or explanation linking aerosol variations to changes in AEF is provided. Data on aerosol concentrations for the sites would be provided or cited (at least qualitative data).
Response: [Thank you for your detailed comments and we have added the references of the relationship between aerosol variations and changes in AEF as in line 133.]
The following minor changes are also recommended:
L41: AEF should be given in kV/m, not kV.
[Thank you and it has been changed.]
L50: Should this read "change in electric field"?
[It’s “induced charges”, not "change in electric field". When the fan-shaped metal sheet rotates, induced charges are generated on the other metal sheet. By measuring the weak induced signal, the value of the atmospheric electric field is then obtained.]
L51-52: This sentence should say that the sensor plates are electrodes that are alternately shielded and exposed to AEF.
[It has been changed.]
L96-98: Appears to have been left in from a template.
[Thank you and they have been deleted in the revised version.]
L111: This is a map, not a schematic diagram.
[It has been changed.]
L120: Should be "of the Campbell CS110".
[It has been changed.]
L129-130: The link between aerosol concentration and AEF should be supported with a reference.
[Thank you for your detailed comments and we have cited the reference of the link between aerosol concentration and AEF in line 133 in the revised version.]
L137: The times in this table seem very approximate (nearest 30 min times, nearest month dates). More accurate sources values and a source should be provided.
[As shown in Table 2 and in lines 135-142, more accurate values have been provided in the revised version.]
L147: Explain what "effective days" means.
[A effective day is a day in which there is no data loss for more than 1 hour in a continuous period. This explanation has been added in lines 153-154.]
L147: Rather than "fairest days", the "greatest number of fair days" seems appropriate.
[Thank you, it has been changed.]
L170 and elsewhere: e.g. 12 o'clock is too informal and 12:00 UT is preferable.
[We have corrected this.]
L182: It doesn't make sense to talk about "the opposite result" for dissimilar quantities. Better phrasing would be "the opposite trend".
[It has been changed in line 200.]
L188: Provide some explanation what is meant by "unavoidable systematic errors".
[The EFM has a certain measurement accuracy, resolution, zero stability, and linearity due to the limitation of circuit components. The stator and rotor of the EFM may leave ice or dust particles, and these dust particles may be charged, which leads to the fact that the AEF observed by the EFM is not the AEF in the atmosphere, and this can lead to experimental errors. In addition, unstable supply voltage leads to unstable rotation between the stator and rotor, which also leads to unavoidable experimental errors. This explanation has been added in lines 208-214.]
L261-262: No sources are cited for these population statistics. Moreover, they don't necessarily provide direct evidence of pollution levels. Consider replacing with more direct evidence of the pollution/aerosol levels.
[Thank you for your very useful recommendations, and we have used the average PM2.5 data for the three stations in 2021 as shown in lines 305-310.]
Author Response File: Author Response.doc
Reviewer 2 Report
The paper is well written, contains interesting material and is acceptable for publication in Universe. Since this is not a field that I work in I cannot say whether the material is totally new or not. Only the authors or another referee could state whether this is correct or not.
The findings of the dual peaks, one occurring after dawn and a second after dusk is interesting. The authors should note that the ionospheric plasma density uplift by horizontal electric fields have the same local time dependences. I am wondering if somehow the vertical and horizontal electric fields are coupled? The authors might wish to comment on this. It may be a mutual mechanism causing both.
During major geomagnetic storms, intense horizontal electric fields cause ionosheric uplift on the dayside and downdrafts on the nightside. Some references to this are JGR 109 A08302 2004 doi:10.1029/2003JA010342; GRL 32 L12S02 2005 doi:10.1029/2004GL021467; JGR 113 A05311 2008 doi:10.1029/2007JA012879. I am just wondering if you could look at one of these published magnetic storms and see what type of vertical electric fields that you see during the same time interval? A short comment in the paper would be very interesting to not only electric field people but also to magnetospheric plasma people.
Author Response
Dear Editors and Reviewers:
Thank you for your kind letter of our manuscript (universe-1938810), "Comparison of atmospheric electric field from 3 global stations from January to December 2021" on November 9, 2022. We revised the manuscript in accordance with the reviewers' comments and carefully proofread the manuscript to minimize typographical, grammatical, and bibliographical errors, which are shown in red. Here, we describe our revision according to the reviewers' comments.
Reviewer #2: The paper is well written, contains interesting material and is acceptable for publication in Universe. Since this is not a field that I work in I cannot say whether the material is totally new or not. Only the authors or another referee could state whether this is correct or not.
The findings of the dual peaks, one occurring after dawn and a second after dusk is interesting. The authors should note that the ionospheric plasma density uplift by horizontal electric fields have the same local time dependences. I am wondering if somehow the vertical and horizontal electric fields are coupled? The authors might wish to comment on this. It may be a mutual mechanism causing both.
Response: [Thank you for your positive comments and some interesting discussions. It is known that the horizontal electric field near surface is in the order of mV under normal conditions, while the vertical electric field is 106 times larger than horizontal electric field. Considering that horizontal electric field is not obvious and easily affected by environmental factors, we have not done some investigations relevant to horizontal electric field. If possible, we will do similar research works as you mentioned in the future.]
During major geomagnetic storms, intense horizontal electric fields cause ionosheric uplift on the dayside and downdrafts on the nightside. Some references to this are JGR 109 A08302 2004 doi:10.1029/2003JA010342; GRL 32 L12S02 2005 doi:10.1029/2004GL021467; JGR 113 A05311 2008 doi:10.1029/2007JA012879. I am just wondering if you could look at one of these published magnetic storms and see what type of vertical electric fields that you see during the same time interval? A short comment in the paper would be very interesting to not only electric field people but also to magnetospheric plasma people.
Response: [Thank you for the great questions and suggestions. Our main research focuses on how space weather activities affect near surface atmospheric electrostatic environment. As you mentioned, the vertical electric field increased during major magnetic storms, the paper named “Statistical relationship between proton precipitation in the south polar gap and the atmospheric electric field” is under reviewing. And we believe that specific detailed scientific questions of the relationship between solar events and electric field will be solved one by one in the future.]
We tried our best to improve the manuscript and made some changes in the manuscript. We earnestly appreciate the Editors/Reviewers’ work and hope that the corrections will be met with approval. Once again, thank you very much for your comments and suggestions.
Author Response File: Author Response.doc
Reviewer 3 Report
The paper presents interesting research on potential gradient variations near the Earth's surface. With some amendments it will be suitable for publication.
Geological conditions are cited as the reason for the form taken by AEF curves at different sites in Figures 2 and 3 (e.g. on L199). Further explanation is required for this attribution, including citations and/or additional data. How are geological conditions different between the sites? Why are atmospheric conditions (like aerosol concentration) not responsible?
Later aerosol behaviour is described (L213-215). However, no source or explanation linking aerosol variations to changes in AEF is provided. Data on aerosol concentrations for the sites would be provided or cited (at least qualitative data).
The following minor changes are also recommended:
L41: AEF should be given in kV/m, not kV.
L50: Should this read "change in electric field"?
L51-52: This sentence should say that the sensor plates are electrodes that are alternately shielded and exposed to AEF.
L96-98: Appears to have been left in from a template.
L111: This is a map, not a schematic diagram.
L120: Should be "of the Campbell CS110".
L129-130: The link between aerosol concentration and AEF should be supported with a reference.
L137: The times in this table seem very approximate (nearest 30 min times, nearest month dates). More accurate sources values and a source should be provided.
L147: Explain what "effective days" means.
L147: Rather than "fairest days", the "greatest number of fair days" seems appropriate.
L170 and elsewhere: e.g. 12 o'clock is too informal and 12:00 UT is preferable.
L182: It doesn't make sense to talk about "the opposite result" for dissimilar quantities. Better phrasing would be "the opposite trend".
L188: Provide some explanation what is meant by "unavoidable systematic errors".
L261-262: No sources are cited for these population statistics. Moreover, they don't necessarily provide direct evidence of pollution levels. Consider replacing with more direct evidence of the pollution/aerosol levels.
Author Response
Dear Editors and Reviewers:
Thank you for your kind letter of our manuscript (universe-1938810), "Comparison of atmospheric electric field from 3 global stations from January to December 2021" on November 9, 2022. We revised the manuscript in accordance with the reviewers' comments and carefully proofread the manuscript to minimize typographical, grammatical, and bibliographical errors, which are shown in red. Here, we describe our revision according to the reviewers' comments.
Reviewer #3: The paper presents interesting research on potential gradient variations near the Earth's surface. With some amendments it will be suitable for publication.
Geological conditions are cited as the reason for the form taken by AEF curves at different sites in Figures 2 and 3 (e.g. on L199). Further explanation is required for this attribution, including citations and/or additional data. How are geological conditions different between the sites? Why are atmospheric conditions (like aerosol concentration) not responsible?
Response: [Thank you for your useful advice. Further explanation of the different curves of different regions has been added as in lines 299-314. For the local geological conditions in a certain region, the radon gas content varies in different regions, radon gas undergo decay and emit α particles, which may further ionize the local atmosphere and positively and negatively charged particles are injected close to the surface. This process changes the distribution of spatial charge density and disturbs the AEF value. Therefore, the baseline characteristics of the atmospheric electric field are different in different regions. Aerosol concentration is also a factor and it can be attributed to PM2.5 concentration as in lines 305-310.]
Later aerosol behaviour is described (L213-215). However, no source or explanation linking aerosol variations to changes in AEF is provided. Data on aerosol concentrations for the sites would be provided or cited (at least qualitative data).
Response: [Thank you for your detailed comments and we have added the references of the relationship between aerosol variations and changes in AEF as in line 133.]
The following minor changes are also recommended:
L41: AEF should be given in kV/m, not kV.
[Thank you and it has been changed.]
L50: Should this read "change in electric field"?
[It’s “induced charges”, not "change in electric field". When the fan-shaped metal sheet rotates, induced charges are generated on the other metal sheet. By measuring the weak induced signal, the value of the atmospheric electric field is then obtained.]
L51-52: This sentence should say that the sensor plates are electrodes that are alternately shielded and exposed to AEF.
[It has been changed.]
L96-98: Appears to have been left in from a template.
[Thank you and they have been deleted in the revised version.]
L111: This is a map, not a schematic diagram.
[It has been changed.]
L120: Should be "of the Campbell CS110".
[It has been changed.]
L129-130: The link between aerosol concentration and AEF should be supported with a reference.
[Thank you for your detailed comments and we have cited the reference of the link between aerosol concentration and AEF in line 133 in the revised version.]
L137: The times in this table seem very approximate (nearest 30 min times, nearest month dates). More accurate sources values and a source should be provided.
[As shown in Table 2 and in lines 135-142, more accurate values have been provided in the revised version.]
L147: Explain what "effective days" means.
[A effective day is a day in which there is no data loss for more than 1 hour in a continuous period. This explanation has been added in lines 153-154.]
L147: Rather than "fairest days", the "greatest number of fair days" seems appropriate.
[Thank you, it has been changed.]
L170 and elsewhere: e.g. 12 o'clock is too informal and 12:00 UT is preferable.
[We have corrected this.]
L182: It doesn't make sense to talk about "the opposite result" for dissimilar quantities. Better phrasing would be "the opposite trend".
[It has been changed in line 200.]
L188: Provide some explanation what is meant by "unavoidable systematic errors".
[The EFM has a certain measurement accuracy, resolution, zero stability, and linearity due to the limitation of circuit components. The stator and rotor of the EFM may leave ice or dust particles, and these dust particles may be charged, which leads to the fact that the AEF observed by the EFM is not the AEF in the atmosphere, and this can lead to experimental errors. In addition, unstable supply voltage leads to unstable rotation between the stator and rotor, which also leads to unavoidable experimental errors. This explanation has been added in lines 208-214.]
L261-262: No sources are cited for these population statistics. Moreover, they don't necessarily provide direct evidence of pollution levels. Consider replacing with more direct evidence of the pollution/aerosol levels.
[Thank you for your very useful recommendations, and we have used the average PM2.5 data for the three stations in 2021 as shown in lines 305-310.]
We tried our best to improve the manuscript and made some changes in the manuscript. We earnestly appreciate the Editors/Reviewers’ work and hope that the corrections will be met with approval. Once again, thank you very much for your comments and suggestions.
Author Response File: Author Response.doc
Round 2
Reviewer 1 Report
In this revised version the authors have corrected only some of the problems evident in the first version.
They have changed the incorrect use of the term “Carnegie Curve” to the correct term “diurnal variation” in most places, but they missed correcting the ones in the Abstract line 22, and on page 9 line 341.
They have not provided a satisfactory explanation for the ZH station data showing zero electric field with zero error for all 57 fair weather days at 16 and 18 UTC for Oct-Dec, and all 36 fair weather days for 18 UTC for July-Sept. As I said in my first review, these results are strange, and incompatible with expectations. In all the hundreds of papers on observations of atmospheric electric fields over the past two centuries no one has claimed real zero electric fields during fair weather conditions, and it is certainly incompatible with theory. As Carl Sagan and others have said, “Extraordinary claims require extraordinary justification”. To anyone familiar with the science of atmospheric electricity, these results are unacceptable, and invalidate the paper. A detailed presentation of all the AEF data with simultaneous cloud and meteorological data, confirming fair weather at the ZH station, is required to accompany this claim for such an extraordinary result.
The authors have revealed in their response to my first review that the error bars shown in the figures for the AEF data are not the standard deviations of the actual data, as expected in any publication of data, but in fact are the small uncertainties due to the instruments themselves. This is highly misleading. Anyone with experience of atmospheric electricity measurements worldwide would know that the scatter in the data is very much larger, and it must be taken into account for a valid interpretation of the results.
The ZH data show uniformly zero values for hours at a time on multiple days. While an electrified non-thunderstorm cloud nearby could give negative values of electric field, it would not give uniformly zero values, and it could not be regarded as a ‘fair-weather’ situation. The result is much more likely to be instrument failure, such as a large zero offset.
The authors have now included references to the observations at Vostok and Concordia in Antarctica (lines 265-274). However, they have not appreciated the fact that the Reading (RG) diurnal variation closely agrees with the Carnegie, Vostok, and Concordia diurnal variations (all sites with low or negligible aerosol content, and low or negligible convection during the selected fair-weather conditions. The Antarctic results are used with corrections for the superimposed solar wind effect.) A proper focus for this paper would be on why the ZH and XAN stations give such anomalous results, compared to what should be taken as a reference curve, given by the Carnegie, RG, Vostok and Concordia observed diurnal variations, which represent the global diurnal variations of ionospheric potential.
The use of the vague term “geological conditions” a number of times starting on line 40 should be replaced by a more specific reference to radon released from soil, as it seems that is what the authors intend.
Author Response
Dear Editors and Reviewers:
Thank you for your kind letter of our manuscript (universe-1938810), "Comparison of atmospheric electric field from 3 global stations from January to December 2021" on November 16, 2022. We revised the manuscript shown in blue in accordance with the reviewers' comments and carefully proofread the manuscript. Here, we describe our revision according to the reviewers' comments.
Reviewer #1: In this revised version the authors have corrected only some of the problems evident in the first version.
They have changed the incorrect use of the term “Carnegie Curve” to the correct term “diurnal variation” in most places, but they missed correcting the ones in the Abstract line 22, and on page 9 line 341.
Response: [Thank you for your detailed comments and we have corrected them in the revised version.]
They have not provided a satisfactory explanation for the ZH station data showing zero electric field with zero error for all 57 fair weather days at 16 and 18 UTC for Oct-Dec, and all 36 fair weather days for 18 UTC for July-Sept. As I said in my first review, these results are strange, and incompatible with expectations. In all the hundreds of papers on observations of atmospheric electric fields over the past two centuries no one has claimed real zero electric fields during fair weather conditions, and it is certainly incompatible with theory. As Carl Sagan and others have said, “Extraordinary claims require extraordinary justification”. To anyone familiar with the science of atmospheric electricity, these results are unacceptable, and invalidate the paper. A detailed presentation of all the AEF data with simultaneous cloud and meteorological data, confirming fair weather at the ZH station, is required to accompany this claim for such an extraordinary result.
The authors have revealed in their response to my first review that the error bars shown in the figures for the AEF data are not the standard deviations of the actual data, as expected in any publication of data, but in fact are the small uncertainties due to the instruments themselves. This is highly misleading. Anyone with experience of atmospheric electricity measurements worldwide would know that the scatter in the data is very much larger, and it must be taken into account for a valid interpretation of the results.
The ZH data show uniformly zero values for hours at a time on multiple days. While an electrified non-thunderstorm cloud nearby could give negative values of electric field, it would not give uniformly zero values, and it could not be regarded as a ‘fair-weather’ situation. The result is much more likely to be instrument failure, such as a large zero offset.
Response: [Thank you for the great questions and comments, and we apologize for our mistake. Considering the strange curve as you said, we reselected the clear-sky atmospheric electric field data at ZH Station and removed some briefly anomalous large values due to instrumental measurements, and we have obtained new results as shown in Figure 2(b) and Figure 3. The new diurnal variation curve has an average value of 116 V/m, which is similar to the mean atmospheric electric field value of Carnegie curve. The curve characteristics remain the same as before, and there are no strange data points near zero. As you mentioned, we have mistakenly used the instrument measurement error as the standard deviation of the actual data. So we have removed all the error bars in Figure 2 and Figure 3. At the time of installation of the atmospheric electric field meter, the zero offset had been recorded and corrected.]
The authors have now included references to the observations at Vostok and Concordia in Antarctica (lines 265-274). However, they have not appreciated the fact that the Reading (RG) diurnal variation closely agrees with the Carnegie, Vostok, and Concordia diurnal variations (all sites with low or negligible aerosol content, and low or negligible convection during the selected fair-weather conditions. The Antarctic results are used with corrections for the superimposed solar wind effect.) A proper focus for this paper would be on why the ZH and XAN stations give such anomalous results, compared to what should be taken as a reference curve, given by the Carnegie, RG, Vostok and Concordia observed diurnal variations, which represent the global diurnal variations of ionospheric potential.
Response: [Thank you for your useful comments and more comparisons have been made between their curves and Carnegie curve, and we think this reason can be attributed to the artificial aerosol pollution and convective processes arising, falling due to sunrise, sunset. The statements have been summarized in the conclusion and abstract .]
The use of the vague term “geological conditions” a number of times starting on line 40 should be replaced by a more specific reference to radon released from soil, as it seems that is what the authors intend.
Response: [Thank you, the description like “geological conditions” has been replaced by “ local content and varied compositions of underground radioactive matter”.]
We would like to thank the referees again for their time and effort to evaluate and improve our manuscript.
Author Response File: Author Response.doc
Reviewer 3 Report
Changes to the paper have improved technical content. However, there are still places where the language is a bit muddled and unclear.
L51: The phrasing makes it sound like plate motion magnetically induces charges in the EFM when its operation is based on electrostatic effects.
L149: "An effective day".
L178 etc: "UT" is preferable to "o'clock". Also be consistent about whether you're using UT or UTC to avoid distraction.
L202: "systematic errors" refer to statistical biases (errors which are consistent between measurements). Instrument resolution, zero-stability and inconsistent supply voltage are more likely to cause random errors.
L203: Should "linearity" be "nonlinearity"?
L291-292: "For the local geological conditions in a certain region" should be deleted.
L292: Should read something like "radon nuclei decay to emit alpha particles which ionize the local atmosphere".
L341: As the other reviewer argued "Carnegie curve" is not a good description of the AEF variation and a different term should be used.
Author Response
Dear Editors and Reviewers:
Thank you for your kind letter of our manuscript (universe-1938810), "Comparison of atmospheric electric field from 3 global stations from January to December 2021" on November 16, 2022. We revised the manuscript shown in blue in accordance with the reviewers' comments and carefully proofread the manuscript. Here, we describe our revision according to the reviewers' comments.
Reviewer #3: Changes to the paper have improved technical content. However, there are still places where the language is a bit muddled and unclear.
L51: The phrasing makes it sound like plate motion magnetically induces charges in the EFM when its operation is based on electrostatic effects.
[Thank you, the statements have been changed to “the induced charges in the environmental electric field have been generated when a metal sheet rotates” .]
L149: "An effective day".
[Thank you and it has been corrected.]
L178 etc: "UT" is preferable to "o'clock". Also be consistent about whether you're using UT or UTC to avoid distraction.
[All similar statements in the paper have been changed to "UT" in the revised version.]
L202: "systematic errors" refer to statistical biases (errors which are consistent between measurements). Instrument resolution, zero-stability and inconsistent supply voltage are more likely to cause random errors.
[Thank you for the reminding to make a clarification. We have changed the statements about the "systematic errors" .]
L203: Should "linearity" be "nonlinearity"?
[Thank you, according to the last comment, we have deleted the sentence containing "linearity".]
L291-292: "For the local geological conditions in a certain region" should be deleted.
[This sentence has been removed in consideration of the first reviewer's suggestion.]
L292: Should read something like "radon nuclei decay to emit alpha particles which ionize the local atmosphere".
[It is consistent with what you understand and this sentence has been changed ]
L341: As the other reviewer argued "Carnegie curve" is not a good description of the AEF variation and a different term should be used.
[Thank you for your detailed comments and we have corrected it.]
We would like to thank the referees again for their time and effort to evaluate and improve our manuscript.
Author Response File: Author Response.doc
