Features of the Change in Climatic Conditions in the Middle Volga Region During the Period 1966-2024 and Their Consequences

Abstract

The objective is to assess the dynamics of inter-day diff erences in air temperature greater than 6 °C and atmospheric pressure greater than 8 hPa in the Middle Volga region in the period 1966-2024 against the background of ongoing changes in the regional climate. Materials and methods. The information base was daily data on air temperature and atmospheric pressure of the ERA5 reanalysis in the nodes of a regular grid with a resolution of 0,25 °С in the Middle Volga region in the period 1966 2024 (number of nodes 1334). Long-term data on these meteorological values were subjected to statistical processing, both for the period 1966-2024 as a whole and for the subperiods 1966-1994 and 1995-2024. The average seasonal values, standard deviations (SD), linear trend slope coeffi cients (LTSC), frequency of interdaily temperature diff erences of more than 6 °C and pressure diff erences of more than 8 hPa by seasons were found. The infl uence of circulation modes on cli mate indicators was estimated. Results and discussions. The region, as well as Russia as a whole, is experiencing climate warming, which is manifested in a signifi cant increase in the average annual temperature in the period 1966-2024 at a rate of 0,42 °C/10 years. Warm ing is most active in winter (LTSC=0.69 °C/10 years), the lowest rate is observed in summer (LTSC = 0,31 °C/10 years). The dynamics of variability of interdaily air temperature diff erences (> 6 °C) and atmospheric pressure (> 8 hPa) in the Middle Volga region for 1966-2024 was obtained. Moreover, in the period 1995-2024 the number of sharp temperature and pressure drops decreases compared to the earlier period 1966-1995, which indicates an increase in atmospheric stability. Conclusions. The most frequently recorded daily temperature drops (> 6 °C) are in the winter period, which exceeds their total number for other seasons. At the same time, a decrease in the frequency of daily temperature drops greater than 6 °C per winter season is noted in the period 1995-2024 compared to the period 1966-1994. There is also a decrease in the dispersion of the average daily air temperature. The frequency of daily pressure drops greater than 8 hPa is most signifi cant in winter, while it slightly decreases from 23 cases/season (period 1966-1994) to 22 cases/season (1995-2024). By season, the frequency of pressure drops is distributed in the following order: winter, autumn, spring, summer.