5:15 PM - 7:15 PM
[ACG38-P02] Assessment of the temporal variability in precipitation trends in southwestern Russia
Keywords:precipitation, climate change, southwestern Russia, trend analysis, meteorological stations, CMIP6 models
The southwestern part of Russia, also known as the southern European Territory of Russia (ETR), is characterized by a high level of spatial inhomogeneity in surface characteristics. The weather formation in this region is influenced by the Black and Caspian Seas, and the Caucasus mountains, which affect large-scale and mesoscale atmospheric circulation patterns. As a result, this area is prone to a number of extreme weather and climate events including extreme precipitation. Studying the observed changes and estimating future trends of the precipitation is therefore an important issue for climate change adaptation measures in the region.
We estimated changes in precipitation characteristics, including extreme events, in the 20th and 21st centuries in the southern ETR based on daily data from meteorological stations and the CMIP6 models. Meteorological stations data in use were collected at the All-Russian Research Institute of Hydrometeorological Information - World Data Center for the period 1966-2023. Also, we examined the results of 34 climate models from the CMIP6 ensemble for the 1900-2100 period for SSP245 and SSP585 anthropogenic forcing scenarios. We calculated moving 30-year trends (with 1-year shift) of different precipitation characteristics based on daily precipitation data in order to understand the temporal variability of precipitation trends and the uncertainty of these tendencies.
The modern climate of the study area is characterized by a significant increase of surface temperature, more pronounced during the summer. Extreme precipitation events occur each year in the study area, resulting in severe flooding and mudslides, among other consequences. However, the temperature growth has not been accompanied by statistically significant trends of the seasonal amounts, intensity, or occurrence of extreme precipitation.
According to meteorological stations data, primarily positive trends of seasonal precipitation amounts were observed for the middle of 20th century both in cold and warm seasons. By the beginning of the 21st century, precipitation growth had slowed down and the trends had shifted from positive to negative. The total amount of precipitation, the number of wet days and the percentage of extreme precipitation in the region had begun to decrease, especially in summer time. It is important to note that a major part of trends is not statistically significant due to an intense interannual variability of precipitation characteristics.
According to CMIP6 models in the 21st century, the winter precipitation for the model ensemble shows inter-decadal fluctuations with periods of positive trends followed by negative trends. Negative precipitation trends are more prominent for summer, particularly from the second half of the 21st century. Furthermore, the frequency of wet days may continue to decrease during summer and the contribution of extreme precipitation events to total precipitation may decrease as well. This effect is more pronounced for the SSP585 climate scenario. However, the CMIP6 ensemble data are characterized by significant interannual variability and inter-model spread that need to be taken into account when interpreting the results.
Thus, the south of ETR is characterized by a decrease of precipitation for the last decades, more pronounced in summer season. Such conclusions have been obtained not only for seasonal precipitation amounts, but also for the number of wet days and the frequency of extreme precipitation. By the end of the 21st century, the changes become more pronounced. The combination of increased temperatures and decreased precipitation, along with their probability, could lead to enhanced dry conditions in the area. These changes could significantly impact agriculture, tourism, and economic development in southwestern Russia.
This research was supported by the Ministry of Science and Higher Education of the Russian Federation [grant number 075-15-2024-554 of 24.04.2024].
We estimated changes in precipitation characteristics, including extreme events, in the 20th and 21st centuries in the southern ETR based on daily data from meteorological stations and the CMIP6 models. Meteorological stations data in use were collected at the All-Russian Research Institute of Hydrometeorological Information - World Data Center for the period 1966-2023. Also, we examined the results of 34 climate models from the CMIP6 ensemble for the 1900-2100 period for SSP245 and SSP585 anthropogenic forcing scenarios. We calculated moving 30-year trends (with 1-year shift) of different precipitation characteristics based on daily precipitation data in order to understand the temporal variability of precipitation trends and the uncertainty of these tendencies.
The modern climate of the study area is characterized by a significant increase of surface temperature, more pronounced during the summer. Extreme precipitation events occur each year in the study area, resulting in severe flooding and mudslides, among other consequences. However, the temperature growth has not been accompanied by statistically significant trends of the seasonal amounts, intensity, or occurrence of extreme precipitation.
According to meteorological stations data, primarily positive trends of seasonal precipitation amounts were observed for the middle of 20th century both in cold and warm seasons. By the beginning of the 21st century, precipitation growth had slowed down and the trends had shifted from positive to negative. The total amount of precipitation, the number of wet days and the percentage of extreme precipitation in the region had begun to decrease, especially in summer time. It is important to note that a major part of trends is not statistically significant due to an intense interannual variability of precipitation characteristics.
According to CMIP6 models in the 21st century, the winter precipitation for the model ensemble shows inter-decadal fluctuations with periods of positive trends followed by negative trends. Negative precipitation trends are more prominent for summer, particularly from the second half of the 21st century. Furthermore, the frequency of wet days may continue to decrease during summer and the contribution of extreme precipitation events to total precipitation may decrease as well. This effect is more pronounced for the SSP585 climate scenario. However, the CMIP6 ensemble data are characterized by significant interannual variability and inter-model spread that need to be taken into account when interpreting the results.
Thus, the south of ETR is characterized by a decrease of precipitation for the last decades, more pronounced in summer season. Such conclusions have been obtained not only for seasonal precipitation amounts, but also for the number of wet days and the frequency of extreme precipitation. By the end of the 21st century, the changes become more pronounced. The combination of increased temperatures and decreased precipitation, along with their probability, could lead to enhanced dry conditions in the area. These changes could significantly impact agriculture, tourism, and economic development in southwestern Russia.
This research was supported by the Ministry of Science and Higher Education of the Russian Federation [grant number 075-15-2024-554 of 24.04.2024].