Frequency of Weak and Strong Winds in the Atmospheric Boundary Layer on the Territory of the Russian Federation Assessed from Data of Long-Term Aerological Observations

Knowledge of the wind regime in the lower layer of the atmosphere is necessary both for studying climate and its variability and for applied problems, primarily for the problem of impurity propagation. Climatic characteristics of the wind regime in the boundary layer, available in a number of sources, have been obtained from aerological data for the 1950s–1960s. Therefore, it is important to obtain them according to more modern data. The characteristics of the wind regime given in the article are determined on the basis of the aerological datasets of the Russian Institute of Hydrometeorological Information, World Data Center (RIHMI-WDC). The data of more than 100 Russian aerological stations and stations from adjacent territories for 1979–2022 are used. For each station at four altitude levels (ground surface, 100, 500, and 1000 m), the following values are calculated: average wind speeds, frequency of calm conditions, frequency of weak and strong winds for four seasons (winter, spring, summer, and autumn), and time series of these characteristics averaged for each consecutive year for the entire study period. Maps of average speeds, frequencies of calm conditions, and weak and strong winds are presented. The features of geographical and seasonal distributions are analyzed, as is the nature of the dependence of characteristics on height. The features of the wind regime on the ocean coast and in the mainland zone are shown. The geographical distribution of the average surface wind speed generally coincides with the distribution given in various sources. Estimates of their variability are made based on time series of average annual characteristics. Due to the significant heterogeneity of time series, it is difficult to make statistically reliable estimates; therefore, numerical values of linear trend coefficients are not given in the article. Only three gradations are considered—positive trend, negative trend, and close to zero. According to the results, it is possible to make an assumption about the decrease in wind speed in the boundary layer over the past 40 years. This is manifested primarily in an increase in the frequency of weak winds at most stations, as well as in a decrease in the average wind speed and the frequency of strong winds. With altitude, these features gradually decrease and, at the level of 1000 m, the trends of variability are practically unnoticeable. This is the most general picture. At individual stations, the time variability may have other features.