Consolidated Amateur Radio Signal Reports as Indicators of Intense Sporadic E Layers

Round 1

Reviewer 1 Report

This paper uses a new method of the consolidated amateur radio reception reports to analyze the presence of Es. The case study with the 28 MHz, 50 MHz and 70 MHz reflection points support the validity of this approach. Though there is a limitation of the coverage in this technique, the new approach could provide better spatial and temporal resolution than the traditional techniques. Some suggestions are as follows.

• The Figure 2 and Figure 3 may be able to be merged into one single figure.
• There is a literal error in the Line 222. Please make some further literal inspections to the whole article.

I suggest this paper could be published in Atmosphere after making some minor revisions.

Author Response

Thank you very much for your helpful comments.

In response to your suggestions:

• We feel that Figure 3 is distinctly different from Figure 2 in that it concentrates on the path midpoints and also includes the coverage estimate (small dots). The coverage estimate, in particular, would not be shown clearly if we combined the two figures. But we do recognise the apparent duplication and have therefore modified Figure 2 to make the two figures more distinct.
• Thank you for pointing out the repetition of the words “level of”, which has now been corrected. We have also checked the rest of the article for similar mistakes.

Thank you again for your constructive review.

Reviewer 2 Report

This paper present a pretty new investigation of Es, utilzing the amateur radio signal as a supplement to detect and study the sporadic E layer. As is known to us, ionosonde or digisonde is a common equipment to measure Es. However, due to the cost, the distribution of ionosonde is pretty sparse. Now the author propose that the amateur radio signal can also be used as a 'part' ionosonde to detect Es, which make full use of the Es influence on radio signal. The method can greatly make up the sparse distribution of Es detection and help us discover more structures of Es. I recommend this paper to have a minor revision before it is suitable for publication.

 

In the introduction, the author misses an important aspect of Es, which shall be added. The Es is always correlated with the sporadic metal layer, of which are regarded as a possible chemical source of the metal ions. There are numerous studies investigating their correlations and the author shall cite some of them (see examples below). This is a clear evidence of the ion-neutral coupling. 

Yuan, T., Wang, J., Cai, X., Sojka, J., Rice, D., Oberheide, J., and Criddle, N. (2014), Investigation of the seasonal and local time variations of the high-altitude sporadic Na layer (Na_s) formation and the associated midlatitude descending E layer (E_s) in lower E region, J. Geophys. Res. Space Physics, 119, 5985– 5999, doi:10.1002/2014JA019942.

Dou, X. K., Xue, X. H., Li, T., Chen, T. D., Chen, C., & Qiu, S. C. (2010). Possible relations between meteors, enhanced electron density layers, and sporadic sodium layers. Journal of Geophysical Research, 115, A06311. https://doi.org/10.1029/2009JA014575

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, 124, 9610– 9625. https://doi.org/10.1029/2019JA026746

 

 

Author Response

Thank you very much for your helpful comments, and particularly for pointing out the omission from the introduction of mention of the Es relationship to the sporadic metal layer.  We have amended the introduction accordingly and included references. We hope that deals with the issue appropriately.

Thank you again for your constructive and helpful review.

Reviewer 3 Report

Good work, can be published in this form.
The approach to using consolidated distributed amateur radio reception for scientific purposes is not very new, but its full implementation is very interesting. The comparison made with regular ionosonde data is important. It will be very interesting to see the same work for auroral latitudes in the future. Not sure if Fig.3 adds anything to Fig.2, perhaps Fig.3 can be shortened.

Author Response

Thank you very much for your helpful comments.

In response to your suggestion about the two figures, we feel that Figure 3 is distinctly different from Figure 2 in that it concentrates on the path midpoints and also includes the coverage estimate (small dots). The coverage estimate, in particular, would not be shown clearly if we combined the two figures. But we do recognise the apparent duplication and have therefore modified Figure 2 to make the two figures more distinct.

Thank you again for your constructive review.