CHANGES IN REGIONAL PRECIPITATION DISTRIBUTION IN RESPONSE TO GLOBAL WARMING

Introduction. Precipitation changes in response to warming are more uneven than before, and this occurs mainly during events that are considered extreme . Unlike temperature, where climate change can be viewed as a simple shift in distribution, the shape of the distribution of precipitation changes with warming, so that rain showers account for a large proportion of total precipitation Materials and methods of research. The results of this work are based on the analysis of precipitation and temperature data from twenty meteorological stations located in the south of the European part of Russia, in the period from 1961 to 2018, and provided by the North Caucasus Department of Hydrometeorology and Environmental Monitoring . To study the precipitation regime, the "basic triad" of precipitation was used: the total precipitation (P), the daily maximum precipitation (P_max), the number of days with precipitation of at least 20 mm (NR20) and average temperatures (T) . For the study, regression statistics of seasonal and annual series of precipitation sums, daily maximums and the number of days with precipitation of at least 20 mm, and average temperatures were calculated . Linear trends characterizing the trend of the value under consideration for the entire observation period from 1961 to 2018 were constructed using the built-in Excel LINEST worksheet function, which returns the values of the slope coefficients, the errors in their calculation, the coefficient of determination of the model R² (D, %), F- Fisher's test to determine the significance of the coefficient of determination R². Results of the study and their discussion. Throughout the south of the EPR in 1961-2018, with the exception of the negative trend of summer precipitation amounts, there was an increase in seasonal and annual precipitation amounts, daily maximum precipitation and NR20, mainly statistically insigniicant In all climatic zones of southern Russia, there was a statistically significant increase in average annual temperatures In the alpine zone, the increase in annual temperature is statistically insignificant (Terskol, a = 0 . 08 °C/10 years, D = 4 %) . In the dynamics of seasonal average temperatures, including in the high-altitude zone, a general pattern was observed - the highest rate of temperature growth in the summer season with the maximum contribution of the explained variance Despite the same positive trend of both the mean annual temperature and precipitation in the south of the EPR, the correlation coef-cients of the pairs of the series "temperature - precipitation sum", "temperature - maximum precipitation", "temperature - NR20" are statistically insignificant at the 5 % level . Against the background of a significant increase in average annual temperature anomalies, the amount of precipitation and the number of days with intense precipitation increase, but statistically insignificantly. The contribution of the trend to the explained variance is greatest for daily maximum precipitation, D = 5 2 %, which is closest to the statistically significant D = 6 . 5 % . When the average annual temperature exceeds the climatic norm by 1 °C, the anomaly of daily maximum precipitation increases by =159 % of the anomalies of daily maximum precipitation at the climatic norm of temperature (АГ = 0 °C), in contrast to the increase in the anomalies of precipitation amounts by 3 % . Conclusions. The revealed tendencies characterize the change in the precipitation regime - the amount of precipitation that fell per month does not increase signii-cantly, but if earlier it was uniform rains, now it is short, torrential . In warmer climates, signiicantly more moisture is contained in the atmosphere due to the almost constant high relative humidity, which leads to an increase in dangerous convective phenomena Thus, it can be predicted that the amount of precipitation will not change, but there will be more extreme precipitation

precipitation amounts, daily maximums, number of days with precipitation of at least 20 mm, average temperatures, water content, correlation, regression, Fisher's criterion, southern Russia

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