The characteristics are presented for the visibility regime at 42 aerodromes in European Russia calculated from the data of aerodrome observations reported in METAR telegrams with 30 minute (more rarely, 1 hour) time intervals. The occurrence frequency distributions of horizontal visibility ≤ 300 m and ≤ 800 m are calculated and analyzed over the period of 2001-2019. The tables are presented and discussed for the annual cycles of the occurrence frequency, as well as for its distributions under different weather phenomena. The occurrence frequency distributions depending on cloud base height, relative humidity, speed and direction of surface wind are presented. The results are also presented for the duration of low visibility episodes: it is demonstrated that such episodes are short, as a rule (for example, the visibility ≤ 300 m is continually observed for not more than 2 hours in 65-85 % of cases). The results of quantification of the correspondence between the occurrence or absence of low visibility and other weather characteristics observed at the same aerodromes demonstrate certain perspectives for developing (at least for several aerodromes) statistical methods to forecast this rather rare phenomenon basing on outputs of numerical atmosphere models. Keywords: visibility, aerodrome observations, annual cycle of low visibility, relative humidity, cloud base height, weather phenomena

A review of literature on the impact of dust and sand storms on the air transport operation is presented. Observational data on dust storms at the aerodromes of European Russia for the period of 2001-2019 are analyzed. The seasonal variations in dust transport episodes at aerodromes and its relationship with visibility changes are discussed. The characteristics of dusty air masses and advection are given. It is concluded that the frequency of dust transfer episodes for the aerodromes under study has decreased over the past five years, except for Gumrak aerodrome (Volgograd). Keywords: dust storm, sand storm, aviation, visibility, seasonal variations, aerodrome оf European Russia

Dust storm episodes at the aerodromes in the Asian part of Russia / Ivanova A.R., Skriptunova E.N., Komasko N.I., Zavialova A.A.// Hydrometeorological Research and Forecasting, 2021, no. 2 (380), pp. 20-42. According to 2001-2020 METAR data, episodes of dust storms at 26 international aerodromes in the Asian Russia causing poor visibility are studied. The conditions for issuing reports on dust storms, their correspondence to the definition of a dust storm are discussed. It was found that out of 337 reports describing dust transport by strong wind, only 7 episodes registered at the aerodromes of Irkutsk, Abakan, Omsk, and Blagoveshchensk corresponded to the classical definition. The others detected at 15 of 26 aerodromes may be defined as “dust events” – the episodes of dust transfer causing the nonessential visibility reduction. The seasonal variation in such episodes and its connection with changes in visibility are studied. The characteristics of dusty air masses and the direction of their advection are given. Keywords: dust storm, dust events, aerodromes of Asian Russia, seasonal variation, trajectory analysis