An Investigation on the Distribution of Martian Ionospheric Particles, Based on the Mars Atmosphere and Volatile Evolution (MAVEN)

Round 1

Reviewer 1 Report

This manuscript presents a Chapman-fitting analysis of the Martian ionosphere for conditions of no solar flares and with solar flares.

Comments:

1. Line 62, or somewhere in the Introduction - Stone et al. 2020 (Science 370, 824) should be cited and discussed. Stone et al. demonstrated transport of water to the upper atmosphere on lofted dust particles.

2. Line 118 - what does 'except the effect of the solar zenith angle' mean here?

3. Why is sec(chi) missing from equations 8 and 15, but is included in equation 7?

4. What is the origin of equation 10, and what are the values used for k?

5. Line 133 - what is meant by 'molecular atom'?

6. Line 140 - what does 'performed to the KP in-situ measurements' mean? Define KP.

7. Figure 1 - The sum of the ion number densities is << the total electron number density. The electron peak is about 8E4 cm-3 versus about 6e3 cm-3 for the positive ions.

8. Figure 1h and Figures 3 and 4 - Electron number density is given in units of per m3, whereas ion number densities are per cm3.

9. Figure 2 - proper caption is missing. Remove placeholder text and add correct caption.

10. Line 264 - discuss possibility of H2O transport upward on dust particles in the context of Stone et al. 2020.

11. Line 277 - Please define MAVEN KP dataset.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

General Comments:

Overall, the manuscript is very interesting and well written. The authors report the interesting characteristics of the Martian ionosphere and also the Martian ionospheric variations observed during active times (during solar storms and dust storms) and quiet times.  In order to probe the theoretical equations modeling density variations in height, the authors made direct comparisons between the measured and modelled values (shown in Figure 1) providing observational evidence of the reliability of the theoretical equations.  Statistical analysis, based on 36 months of multi-instrument MAVEN data (obtained after an extensive search of the 2016-2022 time period), revealed the variations of peak density in terms of solar zenith angle (shown in Figure 2), during and after C-class solar flare events (shown in Figure 3), and during the various seasons (when dust storms were present and absent; shown in Figure 4).  As concluded, the new findings provide new information and insights into the Martian ionosphere, which shows similarities to the Earth’s ionosphere, and thus lead to the better understanding of the planetary ionosphere.

A few suggestions to improve the manuscript are listed in Detailed Comments (see below). Therefore, I recommend Minor Revisions.

Detailed Comments:

L140: KP is not defined: “KP” should read “Key Parameters (KP)”

 L184-187:  There is something wrong with this figure caption.  Figure 2 needs a correct figure caption.

L240: “Figures b, d and e” should read “Figures b, d and f”

L305-306: link (https://search-pdsppi.igpp.ucla.edu/mission/MAVEN/MAVEN/LPW) does not work: return message is “This search-pdsppi.igpp.ucla.edu page can’t be found”.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Revised manuscript looks fine.