Updated Climatology of Mesospheric Temperature Inversions Detected by Rayleigh Lidar above Observatoire de Haute Provence, France, Using a K-Mean Clustering Technique
, Philippe Keckhut 1, Alain Hauchecorne 1, Robin Wing 2, Mustapha Meftah 1 and Ghazal Farhani 3Round 1
Reviewer 1 Report
The paper presents climatology of mesosphere inversion temperature by statistical analyses using Rayleigh lidar located in the douth of France. The four decades data set is long enough and rare for mesosphere. The MILs were restrict between 60-80 km. They found three distinct classes of MILs by using k-mean method. The results show a strong seasonal clycle with the largest occurrence in winter and smallest occurence in summer. The paper focuses on a niche topic and is interesting.
Major comments:
(1) Lines 76-79：The part is confused. The top side of the thermal layer is exosphere? The exospheric temperature is nearly constant. The negative temperature gradient with decreasing altitudes means that positive temperature gradient with increasing altitudes in the thermosphere? Please check the section.
(2) Lines 273-286: The section is confused. The results are originate from previous study? Or some results are from the paper? If compare to previous study, tell differences. Lack of unit for 5-10. Normalization for 2-5 Kkm-1.
(3) Lines 303-304: Solar cycle is mentioned, but there is not any index about solar cycle in Figure 5. The correlationship is not clear.
(4) Lines 308: Why are a fewer cases reported between 1986-1995 and blank cases between 2010-2015?
(5) Lines 314-315: The improve quality of the Ryleigh Lidar is mentioned as the reason why the number of MILs increases in recent year. However, the selected method has been still primary. So what are the differences of selected MILs between recent years and past years?
(6) Figure 6 shows the k-mean clustering reslutsb, but 3-D can not clearly show the relationships and suggest using 2-D.
minor comments:
(1) Lines 69-70: 'This huge variability is also a critical issue for atmospheric re-entry either space shuttle, missile, or natural materials like meteorites.' I remenber that the re-entry altitude is about 180 km, which is far higher than MILs altitudes.
(2) Lines 106-107: The values of associated errors should be mentioned.
(3) Lines 222-223: The values of estimated temperature error should be given. If the values chang with altitudes, make it clear.
(4) Lines 292-293: Please check the sentence.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
I find no major technical issues about the manuscript. However, there are numerous errors in English grammar, verb tense, spelling, and sentence structure throughout. I suggest a careful rewrite of the text to correct them. I list some additional suggestions/questions below:
Line 79—Provide a reference.
Figure 3—Correct the spelling of temperature in the embedded legend.
Lines 214-224—This paragraph has redundant or repeated material and needs to be rewritten, particularly regarding the three criteria for MILs.
Line 230—How do you get N form the temperature profile?
Lines 235-241—Sentences are repeated here.
Line 268—I suggest “See also Figure 7”.
Line 283—I do not see a negative temperature gradient during winter in Figure 4.
Line 304—Do you have a mechanism to explain a correlation of MIL frequency with the solar cycle?
Lines 363-375—This paragraph repeats information in the previous paragraph.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
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Comments for author File: Comments.pdf
Author Response
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Round 2
Reviewer 3 Report
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Comments for author File: Comments.pdf
Author Response
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