Middle Latitude Geomagnetic Disturbances Caused by Hall and Pedersen Current Circuits Driven by Prompt Penetration Electric Fields

Round 1

Reviewer 1 Report

This paper investigates the geomagnetic disturbances at middle latitudes caused by Hall and Pedersen current circuits. The H-D and H/D-EEJ correlation have been measured based on 78 DP2 cases in morning and 56 DP2 events in afternoon from YAP and PTK stations. It is a good work on understanding the effects of prompt penetration electric field from high latitudes on the middle latitude ionosphere. However, there still exist several problems. I recommend this article could be accepted after a minor revision.

1. Line 58. “The R1 FACs flow into the equatorial ionosphere …” might confuse the readers. Because R1 FACs are only observed at high latitudes. Please explain it?
2. Line 62. Equatorial currents here might be EEJ. Hence, the relationship between EEJ and electric field, cowling ionospheric conductance should be given here. Furthermore, a series of EEJ or CEJ works should be cited (e.g., Lühr et al., 2008; Wang H et al., 2020, JGR; Yamazaki and Maute, 2016, Space Sci Rev; Yamazaki et al., 2021, GRL; Zhang KD et al., 2021, 2022, JGR).
3. Line 134-137. “we further confirmed that the R1 FAC dynamo …” this sentence might be not suitable here. You should move it to discussion or other sections?
4. Line 143. The method of the moving average the time window of 60 minutes. Are there any previous works using it to remove the background?
5. Line 146. Multiple by three times for better visibility? This might be not physical. Are there any previous works about this method?
6. Line 156. The high correlation coefficient between PTKH and EEJ means the strong relationship between those two. However, we cannot say no significant effects from magnetospheric currents unless the correlation between magnetospheric currents and PTKH or EEJ is estimated. Thus, here, you should remove the related words or give the correlation between magnetospheric currents and ionospheric currents.
7. Line 190-192 about the time window should be removed or rephrased to avoid the repetition.
8. Line 225. The REPPU model should be introduced here
9. The detail information of the simulation case in figure 4 should be given.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Authors present analysis of variations of the H and D components of the geomagnetic field at middle and low latitudes during DP2 events and easy to identify PPEF events using data from mid-latitudinal magnetometers.

 

The core of the paper is the statistical data analysis (correlation) to prove a hypothesis discussed in the Introduction and Conclusion sections. However, it seems to me that the presentations of the results themselves (even with the simulation part) are unproportionally small compared to the parts of the paper where the tested hypothesis is discussed. Please give more information about the data analysis and its results. For example, plots showing distribution of correlation coefficients for AM and PM cases (e.g., histogrammes) are needed, statistical significance of the found correlation coefficients have to be calculated as well.

 

Other comments: 

1. There are too many abbreviations that make reading very difficult.There are plenty of phrases like “... positive PI of SC occurs in PM…”  I’m sure that, e.g., using “morning” instead of “AM” and “evening” instead of “PM” wouldn’t increase the length of the paper significantly, and “PI” and “SC” are not that abundant in the text to use corresponding abbreviations.
2. P. 3, l, 95 “... but the number of nis…” What’s “nis” ???

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The responses are fine and the manuscript can be accepted in my view

Reviewer 2 Report

I'm  satisfied with the revision made and think the paper can be accepted