Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I have thoroughly reviewed the manuscript titled "On the role of abrupt solar wind pressure changes in forbidden energetic electron enhancements" by Alla V. Suvorova and Alexey V. Dmitriev. The study presents an interesting analysis of three Forbidden Energetic Electron (FEE) events that occurred during the greatest geomagnetic storms. The authors propose that abrupt and significant changes in solar wind pressure are the key drivers of the observed FEE enhancements, attributing the enhancements to radial inward transport of electrons caused by electric drift. While the study provides valuable insights, there are several issues that need to be addressed to strengthen the manuscript.

 

Major Issues

1. Data Selection and Multi-point Analysis:
The FEE events in this study were identified using data from NOAA/POES satellites. Given the importance of understanding the spatial and temporal dynamics of these events, it would be beneficial to incorporate data from other satellites within the magnetosphere for a multi-point analysis. This would provide a more comprehensive understanding of the FEE events and their spatial distribution. The authors should justify why they did not consider data from other satellites and discuss the potential benefits of a multi-point approach.

2. Time Delay Estimation:
The authors used ground-based magnetic observations to refine the time delay of solar wind structures impacting the magnetosphere. However, the estimation of this time delay can be uncertain due to the dynamic nature of the Earth's magnetic field. The authors should discuss the potential uncertainties associated with this method.

3. Mechanism of FEE Enhancements:
The study assumes that FEE enhancements are due to the rapid injection of electrons from the inner radiation belt into the forbidden zone via electric drift. While this mechanism is plausible, it may oversimplify the complex processes involved. The authors should address the complexity of the Earth's magnetic field structure and its dynamic changes, which could influence electron transport. A more detailed discussion on how these factors might affect the observed FEE enhancements would enhance the robustness of their conclusions.

4. Generalizability of Conclusions:
The conclusions drawn in this study are based on FEE events during three super storms. These events may have unique characteristics that do not fully represent all geomagnetic storms or different solar activity cycles. The authors should caution against overgeneralizing their findings and discuss the potential limitations of their study. This would provide a more balanced perspective and highlight the need for further research to validate their conclusions across a broader range of conditions.

Minor Issues

Figure 1 appears to have layout issues.

In summary, while the study presents interesting findings on the role of solar wind pressure changes in FEE enhancements, the authors need to address the aforementioned issues to enhance the credibility and applicability of their conclusions.

Author Response

Please see the attachment

Author Response File: Author Response.doc

Reviewer 2 Report

Comments and Suggestions for Authors

Article review to

On the role of abrupt solar wind pressure changes in forbidden energetic electron enhancements

Autors: Alla V. Suvorovova, Alexey V. Dmitriev

 

In their paper, the authors analyze three cases of sudden increases in the fluxes of quasi-trapped energetic electrons under the Earth's radiation belt (ERB) during three major geomagnetic storms.  This increase, known as forbidden energy electrons (FEE) amplification, has not yet been reliably resolved although it has been observed for several decades. Their observations are made by NOAA/POES satellites in low Earth orbit.  The reason for the imperfect explanation of the existence of FEEs is that they last only a few minutes and are observed in a complex geomagnetic space at different altitudes L, filled with interplanetary and terrestrial magnetic fields of different intensities, electric currents of different intensities, geomagnetic activity and solar activity (pressure and speed of solar wind particles). The analysis was done for three electron energy levels (>30, >100 and >300 keV) measured with the MEPED telescope, which contains electron detectors. All of these quantities interact with each other on different timescales and sometimes the result of the interaction is different. The authors discuss the various causes of FEEs in detail in the Introduction.

The authors focused on the search for (1) key mechanism parameters and (2) solar wind drivers or triggers. To do so, they used three time-differentiated cases during strong geomagnetic storms, which were initially thought to be the main triggers of FEEs. Based on the solved three cases, the authors found that neither the magnetic component of Bz nor the convective electric field could be the driver nor the trigger of FEE in these cases. Their trigger turned out to be a sudden and significant change in solar wind pressure (the result of highly dynamic and most energetic phenomena on the surface of the Sun - flares and coronal mass ejections). The analysis of the studied cases is graphically illustrated and verbally discussed in detail.

   I have no comments on the method of analysis itself. The authors' conclusion is not surprising to me and will undoubtedly contribute to a more complete model of the Earth's magnetosphere and the phenomena occurring in it, as well as their interaction with the manifestations of solar activity.

   The literature is adequate to address the issue and I recommend the paper for publication.

   Two formal comments:

1/ It is not customary to put citations in the abstract

2/ FEE is defined in the abstract. There is no need to repeat it on page 2, line 46

Author Response

We appreciate the Reviewer for the comments and positive assessment of our study.

Comment 1:

“1/ It is not customary to put citations in the abstract”

Reply:

The reference represents the continuity of our previous contribution to the journal “Universe”.

 

Comment 2:

“2/ FEE is defined in the abstract. There is no need to repeat it on page 2, line 46”

Reply:

Usually the abstract is considerate as the separate part of the manuscript.

Reviewer 3 Report

Comments and Suggestions for Authors

Please find the comments in the attached files.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I am satisfied with your responses to the previous review comments. After careful consideration, I believe your manuscript has been sufficiently revised and improved. Therefore, I recommend that the paper be published in its current form.