Regional Spatial and Temporal Variability of Annual and Seasonal Air Temperature

Abstract

The purpose of the article is to show the regional dynamics of annual and average seasonal air temperatures, to update the climatic norm of characteristics and to present the spatial variability of quantitative indicators. Materials and methods. The initial data sample represents a series of 840 values of average monthly temperatures and 70 values of average annual temperature for each of the 9 meteorological stations in the Voronezh Region. The total sample volume was 8,190 values. The regional dynamics of average annual air temperature was investigated by means of a sequential chronological comparison of average values for the decades 1951-2020 with graphical presentation of calculations. A linear trend was used to identify trends in average annual air temperature. The spatial distribution of annual and average seasonal temperatures was performed by geographic interpolation using MapInfo Pro 15.0 software and Vertical Mapper module. Results and discussion. The multiyear dynamics of the average annual air temperature shows an accelerated increase from 1988 to the present. In 1991-2020, the average temperature increased on average by 0.5 °C/decade. The intra-annual seasonal distribution of average temperatures shows an increase in all seasons of the year, but with predominance in winter and spring. The period 1988-2020 is characterised by higher temperature values than 1951-1987 with extreme values for winter of 3.3 °C (m. Anna) and 1.8 °C (Boguchar weather station), and for spring of 2.0 °C (Anna weather station) and 1.4 °C (Kalach weather station). In summer and autumn, the increase in average values is comparable to each other and varies in the range of 1.3 -0.3 °C. The exception is a 0.2 °C decrease in average temperature for Kalach weather station. Conclusion. In the regional dynamics of average annual and seasonal temperature, a constant increase is observed. The main contribution to the annual dynamics is made by more intensive heating of the surface layer of the atmosphere in the winter and spring seasons. Smoothing of interseasonal diff erences in the intra-annual distribution of air temperatures is noted. The updated climatic norm of seasonal temperatures in the Voronezh region takes the following values: spring – 8.0; summer – 20.3; autumn – 7.5; winter – minus 5.4 °С. In the spatial distribution of average annual and seasonal temperatures there is a geographical pattern of increase from north to south.