ATMOSPHERIC DUST TRANSPORT FROM THE CASPIAN REGION OVER THE EUROPEAN PART OF RUSSIA: HEAT WAVES AND PRECIPITATION IN DIFFERENT SEASONS

Asshown by the results of continuousobservations of atmosphericaerosol characteristics at A.M.Obukhov Institute of Atmospheric Physics of Russian Academy of Sciences (IAP RAS) in 2020-2024,episodes of long-range dusttransport from aridand semi-arid regions near the Caspian Sea [1] are observedin Moscowregion almost everyyear, causing an abnormal increase in the concentration of surface aerosol(exceeding the average daily MPC value for PM₁₀). The dust component of atmospheric aerosol plays an active role in the atmosphere, affecting itscomposition and radiationbalance, as well as influencing on terrestrial ecosystems,biogeochemistry of water objectsand land, human health and livingconditions.

The purpose of this workis to identifyepisodes of long–range atmosphericdust transportfrom the southeastern regions through the center of European Part of Russia (EPR) indifferent seasons of 12years (2014-2025),their commonfeatures and differences,their effecton airtemperature and precipitationin the center of EPR. In addition to the data from the IAP RASfor the city centerand suburbsnear Zvenigorod,data onaerosol composition obtainedat the stations of State Budgetary Institution Mosecomonitoring[https://mosecom.mos.ru /] indifferent districts of Moscow were used, as well the weather data from the sites [http://rp5.ru; http://pogodaiklimat.ru]. Spatial distributions of dust mass in the surface air andin the atmospheric column,and also of AOD₅₅₀ value, were analyzed using the MERRA-2 reanalysis resources [http://gmao.gsfc.nasa.gov"reanalysis/MERRA-2/]. 

The frequency of dust episodes from the Caspian Sea in the Moscow region is unevenly distributed over the years under consideration, and the duration of such episodes is also different (from 3 to 10 days). The most powerful (long-lasting and distant) episodes are observed in spring and autumn. Two episodes of atmospheric dust transport from the Caspian Sea through the center up to the Arctic regions of EPR, when the falling snow in the Arctic was colored [2,3], were observed in early spring and in winter.

In the center of EPR, when dust and heat are transported from the southeastern regions, there is not only an increase in the concentration of coarse aerosols PM₁₀,butalso a change in the optical properties of the atmosphere as awhole. In addition, in such months, the airtemperature andprecipitation changeincomparison with the monthly climatic norm(by2.8and2.1°C and by -13.3 and +5.7mm during the warm andcoldmonths, respectively). The ratio of dust mass propagating in the atmosphere insideandabovethesurface mixinglayeralsovariesseasonally according tovertical convection efficiency in the lowertroposphere during a year.

1. Vinogradova A.A. et al. Atmos. Ocean. Optics. 2024. V. 37, No. 6. P. 620–629. DOI: 10.1134/S1024856024700842 
2. Shevchenko V.P. et al. Dokl. Earth Sc. 2010. Т. 431. No. 2. С. 497-501.
3. Gubanova D.P. et al.  Dokl. Earth Sc. 2025. 522, 14. https://doi.org/10.1134/S1028334X25605681