Extreme phenomena in the Lake Baikal basin: tropical nights and hot days as indicators of climate warming (Eastern Siberia, Russia)

• Published in: Theoretical and applied climatology 2024-07, Vol.155 (7), p.6581-6590
• Main Authors: Potemkina, Tatiana, Potemkin, Vladimir
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Sciences; Climatology; Earth and Environmental Science; Earth Sciences; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0177-798X; 1434-4483
• DOI: 10.1007/s00704-024-05031-4

The analysis of air temperature data from May to September for the period 1966–2022 has revealed the occurrence of extreme phenomena, such as tropical nights and hot days, in the Lake Baikal area. The occurrence, multiyear and intra–annual variability of these extreme phenomena was investigated for the first time. The analysis identified two groups of stations, which are differ in the number and distribution of tropical nights and hot days. The first group, which includes inland and coastal stations, has higher values of the frequency of occurrence of tropical nights (0.21–1.68 days yr –1 ) and hot days (0.74–8.05 days yr –1 ). The second group, consisting of coastal, highland and island stations, has predominantly tropical nights (0.19–0.26 days yr –1 ). After 1990, these extreme events became more frequent. Tropical nights occur between June and September, while hot days are common from May to August, with the highest frequency of both in July. In this month, the proportion of tropical nights and hot days is identical and is 57% of their total number. July is the hottest month in the region. The increase in the frequency of tropical nights and hot days in the Baikal region is mainly due to global warming and changes in global circulation. The occurrence and variability of these extreme phenomena also depend on various factors related to the peculiarities of regional climate warming and local circulation of air masses, as well as on environmental conditions surrounding each station.