Sensitivity of the 4–10-Day Planetary Wave Structures in the Middle Atmosphere to the Solar Activity Effects in the Thermosphere

Round 1

Reviewer 1 Report

Authors need to correct same mistake (line 110 word 3, and line 131 word 4.

Author Response

Good afternoon!

Thank you very much for your comment. We appreciate your opinion and have made the appropriate changes to the text.

Sincerely, Koval A.V. and co-authors

Reviewer 2 Report

Comments on “Sensitivity of the 4 - 10-day planetary wave structures in the middle atmosphere to the solar activity effects in the thermosphere”.

In this paper, Numerical simulation of the general atmospheric circulation was performed to estimate changes in the westward travelling planetary wave amplitudes. Digital ionosonde observations showed that the MUAM model is capable of reproducing the PW modes at thermospheric heights. Especially, they studied how the changes in the thermosphere under different solar activities influence the wave amplitudes. They found that the PW reflections can contribute to a significant change in the proportions of the PW wave energy, which penetrates up into the thermosphere from the middle atmosphere, and also the energy reflected downward to the lower atmosphere. The results are interesting and deserve publication on Atmosphere.

Author Response

Good afternoon!

Thank you very much for your comment. We appreciate your opinion!

Sincerely yours, Koval A.V. and co-authors

Reviewer 3 Report

This paper is the flollowng up work of Koval et al., 2019. It provide a sensitivity analysis of different component planetary waves response to different solar activity with a general circulation model. First they employ the digisonde observed nmf2 to validate the model output. Based on the validation, they perform analysis on different PW components. They found that PW are influenced not only by changes in atmospheric refractive index and  Eliassen-Palm flux, but also by different PW reflection in the lower thermosphere. When solar activity is high, PW amplitude are larger in thermosphere but smaller than the middle atmosphere. However, there are several places need to be revised before it is suitable for publication

1 The author appears to ignore the 6-day wave, which has been a hot topic in the Aeronomy community. There are a lot of papers but the author  totally ignores. I suggest the author at least acknowledge the previous studies on 6-day waves and add some references such as

Gan, Q., Wang, W., Yue, J., Liu, H., Chang, L. C., Zhang, S., Burns, A., and Du, J. (2016), Numerical simulation of the 6 day wave effects on the ionosphere: Dynamo modulation, J. Geophys. Res. Space Physics, 121, 10,103– 10,116, doi:10.1002/2016JA022907.

2 Again, the author tested 4 5 7 10 16day waves, and leave the 6-day wave. out

3 For the conclusion that the high solar activity can generate larger amplitude of PW in the thermosphere but lower amplitude of PW in the middle atmosphere, is there any other previous studies that get similar conclusion with authors? 

4 For the models, the author said the geomagnetic torque is calculated based on IRI and NRLMISS. Geomagnetic torque is not a common word, so it seems that there is geomagnetic activity in the model? Or there is no geomagnetic forcing in the model? 

Author Response

We would like to thank the Reviewer for the very useful comments and suggestions. We addressed all of them. Our comments are given after double-slash below.

This paper is the flollowng up work of Koval et al., 2019. It provide a sensitivity analysis of different component planetary waves response to different solar activity with a general circulation model. First they employ the digisonde observed nmf2 to validate the model output. Based on the validation, they perform analysis on different PW components. They found that PW are influenced not only by changes in atmospheric refractive index and  Eliassen-Palm flux, but also by different PW reflection in the lower thermosphere. When solar activity is high, PW amplitude are larger in thermosphere but smaller than the middle atmosphere. However, there are several places need to be revised before it is suitable for publication
 // Thank you very much for your comment! We appreciate your opinion

1 The author appears to ignore the 6-day wave, which has been a hot topic in the Aeronomy community. There are a lot of papers but the author  totally ignores. I suggest the author at least acknowledge the previous studies on 6-day waves and add some references such as
Gan, Q., Wang, W., Yue, J., Liu, H., Chang, L. C., Zhang, S., Burns, A., and Du, J. (2016), Numerical simulation of the 6 day wave effects on the ionosphere: Dynamo modulation, J. Geophys. Res. Space Physics, 121, 10,103– 10,116, doi:10.1002/2016JA022907.
//We've added a link and mention of the 6-day wave. Indeed, the spectrum of planetary waves is large, not all waves were included in our study. For example, in addition to the 6-day, quasi-two-day wave, or eastward propagating Kelvin waves, were left for further study.

2 Again, the author tested 4 5 7 10 16day waves, and leave the 6-day wave. out
// Corrected

3 For the conclusion that the high solar activity can generate larger amplitude of PW in the thermosphere but lower amplitude of PW in the middle atmosphere, is there any other previous studies that get similar conclusion with authors? 
//Yes, this effect was described and interpreted before. We added some information to the discussion of the results.

4 For the models, the author said the geomagnetic torque is calculated based on IRI and NRLMISS. Geomagnetic torque is not a common word, so it seems that there is geomagnetic activity in the model? Or there is no geomagnetic forcing in the model? 
//We partially reformulated the description of solar activity accounting in the MUAM to avoid misunderstanding. Changes in geomagnetic activity can be parameterized in the MUAM but this is out of scope of the current study.

Sincerely yours, Andrey Koval and co-authors

Round 2

Reviewer 3 Report

The author has answerd all my questions and concerns. Now the paper is ok to be published