Dear Dr Hall,

I have received two largely positive reviews of the revised version of your manuscript. One of the reviewers recommends publication as is, the other requests some minor revisions. In detail, the reviews state:
Report # 1:
The new publication represents a significantly extended and, importantly, consistently analysed database on mesospheric turbulence. Regardless of all the drawbacks related to technique limitations, this paper presents an update to unique data and its analysis which connot be found elsewhere.
Report # 2:
I would like to thank the authors for significant modifications to the manuscript. In particular, I find very useful broader discussion of long-term changes in the MLT region from independent studies. Inclusion in the analysis more recent data from Tromso agrees with the overall trend reported in the earlier manuscript, which I find encouraging. However, the authors did not consider the exercise I suggested earlier, e.g. test of sensitivity of conclusions to the data availability period and to the end point values.
Figures 1 and 2 also illustrate the point I was making earlier: adding only 16 months of data changes the trend from 1.2km/decade to 1.6km/decade. The reported trend is highly sensitive to the number of data points and to the end point values. In particular, low turbopause height in 2001-2002 seems to be driving the reported trend. Is the trend still observed if 2001 and 2002 Tromso data excluded from the study? How the trend changes if limited number of years included, with changing data availability period? Answers to such questions would make the study stronger. Note that I do not question inclusion or exclusion of certain data points; there might be real physical reasons behind them. However, I am concerned that these physical reasons might be not related to a trend, but to variations on a shorter time scales.

On another hand, observational evidence reported here adds to the existing evidence of geographic variability in long-term changes. As authors put it, ‘dynamics at this geographic location may be pathological’. Adding few more references with evidence for large changes in this region could benefit the paper. I could suggest Shinbori et al., 2015, Earth Planets Space, where negative trends over Europe were detected from many instruments.

++++++++ End of reports

I would like to encourage you to consider the comments of the two reviewers carefully and submit a revised version of your manuscript, including a discussion on issues raised within report #2.

Sincerely,
Gabriele Stiller