Assessment of changes in the characteristics of the ice regime of the Lower Yenisei in contemporary climatic conditions

Relevance. The area of Lower Yenisei is a part of the Russian Arctic territory, which is sensitive to modern changes of climatic conditions. Many types of economic activities are associated with the timing and duration of ice phenomena on the rivers of the Arctic zone. Methods. To analyze the inter-annual changes in the characteristics of the ice regime of Lower Yenisei (from Yeniseisk to Dudinka) for the period from 1938 to 2021. An electronic database was created containing the duration of ice formation, the duration of ice phenomena, the dates of the beginning and end of these phenomena, as well as the maximum water levels during the opening phase (ice break). The article presents a methodological approach in identifying trend components for the observation periods in 1938–1975 and 1976–2021, as well as the direction of changes in the duration of ice phenomena and ice formation, with a check of the trend equation for statistical uniformity. Results. Ice phenomena after 1975 began to occur later and end earlier by an average of 2–3 days; ice formation began to occur later by 3–5 days, ending earlier by a week. An analysis of the maximum water levels during the break-up phase showed a tend to decrease for the maximum water levels. An analysis of the variability in the duration of ice phenomena and ice formation showed that both characteristics decreased after 1975: the duration of ice phenomena decreased by 2–5 days, the duration of ice formation by more than a week.