О сезонной изменчивости характеристик тропопаузы в предгорных районах Северного Кавказа по данным ERA-5 (Copernicus) и MERRA-2 (NASA)

Abstract

Based on the ERA-5 (Copernicus) reanalysis database, the seasonal variability of the height and thickness of the tropopause in the atmosphere is shown for the foothill region near the city of Vladikavkaz, North Ossetia-Alania, Russia. Two algorithms are used to determine the boundaries of the tropopause and its thickness (here it is the vertical distance between the upper and lower boundaries of the tropopause), based on the definition of the cold point and the gradient definition of the World Meteorological Organization. It is shown that in the summer season the tropopause is higher and less thick, while in cold seasons the tropopause is lower and has a significant thickness (sometimes two tropopauses are recorded). The observed seasonal variability of the tropopause height is compared with that calculated theoretically for the adiabatic temperature. Satisfactory correspondence of some characteristics of the tropopause is observed. Statistical estimates of the trends in changes in the height and temperature of the cold point of the tropopause are calculated, which are in satisfactory agreement with the corresponding trends calculated theoretically on the basis of trends in changes in surface temperature according to the MERRA-2 (NASA) reanalysis data in the study area.