Round 1

Reviewer 1 Report

Report by Reviewer

on the paper atmosphere- 1237141 "AIM-E: E-Region Auroral Ionosphere Model" by Nikolaeva et al.

The paper introduces E-region auroral ionosphere model (AIM-E). The AIM-E model allows calculation of vertical profiles of electron content at high latitudes in the altitude range from 90 to 150 km. The authors demonstrate several applications of the model for prediction of E-layer both locally and globally during quiet and disturbed conditions. It was found a very good agreement of the model predictions with observations. Hence, the model can be used successfully for space climate and space weather applications. Unfortunately, the presentation of the model and equations sometimes are not very clear (see comments below). This part should be improved.

Comments

1. Line 146: Is this Equation (1)?
2. Equation (2.2):

2.1. What is s(z)?

2.2. I do not find q(z) in the equation

3. Line 194: I do not find equations (1) & (3)
4. Line 204: What is h?
5. Line 255: the equation should be revised. What is the unit of foE?
6. In Figure 3, the time is presented in portions of hour, but in the text – in UT. This is very inconvenient. Is it possible to indicate the time in the text also in portions of hour? For instance, 00:36:18 UT (0.603 h)
7. Figure 3: It looks like the AIM-E electron density does not correlate with the fluxes of electrons with energies <1 keV. Is this correct? How can you explain this?
8. Figure 4. The AIM-E prediction is systematically smaller (up to 50%) than the observations. How can you explain this underestimation?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper describes an Auroral E region ionosphere model that include all major species in the E region high-latitude ionosphere. And the author validates their model results by comparing them with satellite and local observations. Finally, they conclude that their model was effective and can be potentially utilized in many aspects. I find that there is a major concern on the paper. Therefore, I recommend this paper to have a major revision before it is suitable for publication

Major concern: the model did not include any transport term , but just has chemistry terms. How can author think that transport is not important? Even it is not important, the author shall provide evidence and discuss about it, not just take it for granted. I recommend author to put more description in removing the possibilities of transport terms. Note that the transport terms include both transport due to velocity and due to eddy and molecular diffusion.

Line 33 remove ‘an’

Line 44-45 the ‘containing the equations of different type’ is redundant, please remove it

Line 75-78 I think this paragraph is too absolute, the author did not give any reference, but argued that global ionosphere model can only reproduce ion composition in the auroral zone. I cannot agree on it without references.

Line 79-87 I would like to remind the author that there are some other so-called local E-region ionosphere model that deal with the minor neutrals and ions between 90-150 km in both daytime and nighttime. Not just 9-14 mentioned in the paper that were only dealing with nighttime. Their results shall also be cited and acknowledged. For example, Cai et al., 2019a and 2019b built a 2D model to study sodium and sodium ions. Chu and Yu 2017 developed an 1D model to study iron and iron ions in the south pole. I strongly recommend the author also cite these papers additionally. The author can also point out these results shortage (for example, there is no observed parameters as input source function)

Cai, X., Yuan, T., Eccles, J. V., Pedatella, N. M., Xi, X., Ban, C., & Liu, A. Z. (2019). A Numerical Investigation on the Variation of Sodium Ion and Observed Thermospheric Sodium Layer at Cerro Pachón, Chile During Equinox. Journal of Geophysical Research: Space Physics, 124 10395– 10414. https://doi.org/10.1029/2018JA025927

Cai, X., Yuan, T., Eccles, J. V., & Raizada, S. (2019). Investigation on the distinct nocturnal secondary sodium layer behavior above 95 km in winter and summer over Logan, UT (41.7°N, 112°W) and Arecibo Observatory, PR (18.3°N, 67°W). Journal of Geophysical Research: Space Physics. https://doi.org/10.1029/2019ja026746

Chu, X., & Yu, Z. (2017). Formation mechanisms of neutral Fe layers in the thermosphere at Antarctica studied with a thermosphere‐ionosphere Fe/Fe+ (TIFe) model. Journal of Geophysical Research: Space Physics, 122, 6812–6848. https://doi.org/10.1002/2016JA023773

Line 234 please clarify what is quiet geomagnetic conditions, such as Kp<2?

Line 256-262, the figures really shows that the model output and ionosonde measurements agrees well. But the author may also add several sentences to speculate why sometimes the small-scale variations exhibit differences, such as June 9 to June 10 at PBK, DIK

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The author had made necessary corresponses to my comments and revisions on the paper. Now the paper's foundation is reliable and sufficient. Here I recommend the paper to be published in the present form

Author Response

Thanks for your review and valuable comments.