General comment:

This manuscript describes a quasi-periodic temperature perturbation (a quasi 26-day oscillation) in the mesosphere during the Northern Hemisphere winter 2016/2017. The combination of simultaneous ground-based OH*(3,1) rotational temperature observations at three mid-latitude stations with SABER and MLS observations provides a convincing observational basis for the analysis.

The authors present evidence supporting the interpretation of this observed quasi 26-day (or 25–27-day) oscillation as a Rossby (1,4) normal mode.

I also find interesting the discussion concerning the possible implications for the identification of solar 27-day signatures.

I consider the manuscript is an interesting contribution. It is clear and well written, in my opinion. I have, only one minor comment, which follows.

Specific comment:

How specific is the quasi 26-day amplitude event observed in 2016/2017?

This study uses data from 1 July 2016 to 30 June 2017, and the pronounced quasi-periodic signal appears only during a relatively limited interval within this period, approximately from DOY 320 to 440, corresponding to a few months around the winter. Since the authors have access to longer ground-based records, I wonder whether it would be possible to investigate whether comparable quasi-26-day events occur during other winters. For example, using Greifswald and Wuppertal observations. I understand that the third station only has observations until mid 2017.

I think that the SABER and MLS datasets also provide the possibility of examining additional winters.