Impact of climate change on occurrence and characteristics of coastal upwelling in Listvennichny Bay (Southern Baikal) from 1941 to 2023

Abstract

The paper presents the results of analysis about relationship between climate changes and coastal upwellings in Listvennichny Bay (Southern Baikal) from 1941 to 2023. A decrease in both full and partial upwellings has been shown since the late 1950s. In addition, an increase in the proportion of upwelling events in August compared to other months during 1970-2023 were found. It also showed tendencies for longer upwelling durations and greater temperature drops during upwelling after 1970 compared to the previous period. Inferred from the analysis of the ERA5-Land data, it was determined that the cause of the observed changes was a global course of decreasing wind activity and a particular redistribution of the proportion of northerly and southwesterly winds in the Bay during the study period. Two cases of full and intermittent upwellings were described and compared. Possible ecological impacts on the Listvennichny Bay due to the combined effects of increasing anthropogenic pressure and less frequent upwellings have been hypothesized.