Review of the magisterial qualification work of the student of atmospheric physics department of Saint-Petersburg State University Popov Andrey Alekseyevich   “Variability of mesoscale waves in the middle atmosphere according to the data of optical measurements”       In the qualification work, A.A. Popov is examined the problem of a variation in characteristics of the night emission of hydroxyl at altitudes 80 – 100 km. The author proposed to use the method of the digital filtration of variations with the periods from 0,4 to 5,4 hr. This method is for the first time used by the author of work for the solution of such problem, and this is undoubtedly the essential merit of the thesis.      As the basis of calculations, A.A. Popov used the results of the measurements of the hydroxyl nightglow with different spectroscopic instrumentations in Alma Ata, Irkutsk and Zvenigorod in the years 2004  –  2017. As a result of data processing with proposed procedure, the author made conclusion about seasonal changes in the average monthly values and mesoscale variances of the emission intensity and rotational temperature of hydroxyl. Differences in the seasonal changes at the different stations the author explains by latitudinal dependence and by differences in the geometry of measurements. Conclusion about long-term trends and influence of solar activity on the hydroxyl emission is made.      The author of work sees a reason for mesoscale changes in the hydroxyl nightglow in internal gravity waves, parameters of which are determined in the considered work.      The text of the qualification work consists of introduction, three chapters and conclusion. In the first chapter, the author brings the reader to the essence of the problem and presents its contemporary state. In the second chapter, the measuring equipment, the procedure of measurements and the network of the observation of mesospheric changes are described. The third chapter contains the results of data processing with the aid of the method of digital filtration. Further, the author analyzes the obtained results and he gives in “the conclusion” the main results of the works.      The qualification work is made at the sufficiently high scientific level. The author convincingly proves proposed assuptions and he adduces argument in favor of obtained conclusions. The text counts 50 pages, bibliography contains 42 citations. Results were reported at the international symposium in Saint Petersburg in the year 2017 and were published in two journals (one of them – abroad).      I consider that the study of A.A. Popov satisfies the requirements, presented to the magisterial qualification works and deserves the “EXCELLENT” mark, and its author is worthy of the master degree.  28  May 2018                               Candidate of physical and mathematical                                             sciences, associate professor of RGGMU                                             _________________       Grigorov N.O