Features of the wave structure of the mesosphere from observations of noctilucent clouds
S.V. Nikolashkin, I.I. Koltovskoi, A.M. Ammosova
The Yakut Scientific Centre of the Siberian Branch of the Russian Academy of Sciences, Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy of the Siberian Branch of the RAS, Yakutsk, Russia
Keywords: mesopause, noctilucent cloud, atmospheric gravitational wave, mesospheric bore, photogrammetic method
Abstract
The article discusses some characteristics of the propagation of atmospheric waves based on photographic observations of noctilucent clouds in the city of Yakutsk. For the first time, a case of observation of the so-called mesospheric boron in noctilucent clouds over Eastern Siberia, recorded synchronously with two cameras of the same type, has been described. The height of the wave front determined by the triangulation method was 79 km. The case of video recording of the propagation of several waves of different lengths with intersecting directions in noctilucent clouds on July 25, 2018 is analyzed. Analysis of the parameters of two waves propagating towards each other showed that the first has average wavelength of 53.5 ± 6.2 km, average phase velocity of 98.4 ± 12 m/s, and northeast direction. The second wave of the scallop type propagated to the southwest with an average phase velocity of 61.5 ± 6 m/s, its average wavelength was 14.8 ± 1.8 km. The speed of westerly wind drift of all clouds was 67 ± 5 m/s.
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