Search

Snow cover (SC) is a great indicator of climate change. It is highly related to temperature. Since the Polish climate faces warmer conditions, changes in the wintertime precipitation phase are observed. More frequent rainfall instead of snowfall is noticed at the end of the 20th and beginning of the 21st centuries. This work presents the spatial distribution, its changes, and variabilities of selected parameters that described snow cover in Poland from 1966/1967 to 2020/2021. The snow characteristics used in the study comprise of SC duration (SCD), the first and last day with SC in the season (SCbeg and SCend), the potential duration of SC season (PSCD), SC stability (SCS), average, maximum and accumulated SC depth (HS, HSmax and AHS). The changes in snow cover waves were analysed. Generally, the Polish climate is mild in the west, where the snow cover is finer and occurs relatively rarely and becomes more continental toward the north‐east, where the snow cover has a better condition to accumulate and preserve. The southern parts of the country are covered by mountain ranges of the Carpathians and Sudetes, where the snow cover remains the longest. The spatial distribution of the coefficient of variability is reversely proportional to SC characteristics—the highest in the north‐east (especially for the HS, HSmax and AHS). The most significant changes in SC are related to a decrease in SCD (5–7 days/decade), HSmax (1–2 cm/decade) and AHS (30–60 cm/decade). At the same time, the snow cover season becomes considerably shorter (especially in the western and central parts—about 10 days/decade). The trends in SCS are not yet significant in most of the country. This study reveals that the snow cover in Poland is under constant change, and the negative trends, which were hardly or not visible at the end of the 20th century, in the last decades have become statistically significant in a greater number of Polish stations. [ABSTRACT FROM AUTHOR]

This work gives an overview on how the projected changes in the extremes in Poland might impact human health and economy. For that purpose, statistically corrected data from 7 regional climate models were used. A significant increase of extreme hot events (i.e. heat waves, tropical nights) is projected for Central and Southern Poland for the end of the 21st century which might seriously affect a society living in large urban areas. Less extreme cold events improve thermal comfort in winter. The negative impact of the warming will affect energy systems with higher demand for electricity in summer and agriculture: an earlier beginning of the growing season and flower blooming will enhance the risk of frost damages in spring, whereas excessive heat will reduce yields in summer. Polish tourism should benefit from higher thermal comfort (except for hot July and August in the far future and warming in the winter season bringing snow cover depletion in the near future). [ABSTRACT FROM AUTHOR]

This study is focused on early fall season in southern Siberia (50-60 N) and is purposed as a contribution to the discussion on the climatic relevance of October Eurasian snow cover. Analysis is based on the daily snow depth data from 43 stations from years 1980-2012, available in the database of All-Russian Research Institute of Hydrometeorological Information-World Data Centre. The snow cover season in southern Siberia starts in early autumn and the number of days with snowfall varies from less than 5 days in the southernmost zone along the parallel 50 N to more than 25 days in the northeastern part of the analyzed area. October snowfall in southern Siberia is associated with occurrence of negative anomalies of sea level pressure (SLP), usually spreading right over the place of recorded intense snowfall or extending eastward from it. Negative anomalies of air temperature at the 850 hPa geopotential level (T850) occurring with increased cyclonic activity are also observed. Negative T850 anomalies are located west or northwest of the SLP depressions. Counterclockwise circulation around low-pressure systems transports cold Arctic air from the north or even colder Siberian polar air from the east, to the west, and northwest parts of cyclones, and induces negative anomalies of temperature. The pattern of T850 anomalies during heavy snowfalls in the eastern part of the southern Siberia is shifted counterclockwise in regard to SLP anomalies: the strongest negative T850 anomalies are located west or northwest of the SLP depressions. [ABSTRACT FROM AUTHOR]

Snow accumulation and associated synoptic conditions in the Russian Arctic are analysed based on snow depth data from 1950 to 2013 from the All-Russian Research Institute of Hydrometeorological Information—World Data Centre data set. The mean duration of snow coverage in the Russian Arctic is approximately eight to nine months. While the period of snowmelt is usually very short (one or two months), snow accumulates during most of the cold season (October–May). Snow accumulation is associated with negative anomalies of sea level pressure and positive anomalies of air temperature, which means increased cyclonic activity over the analysed region. The cyclones differ in intensity and localization, depending on the area of snowfall. In the western part of the Russian Arctic the cyclones and air masses that bring snowfall may originate from the North Atlantic, while in the eastern part they originate from the Bering Sea, Okhotsk Sea or the North Pacific. The cyclones that bring snowfall may also form locally along the zonal border between two different air masses: the very cold, polar, continental air originating from the Siberian High and the Arctic air from the north, which is often warmer and always more humid than the continental air. [ABSTRACT FROM AUTHOR]

The mean duration of snow coverage in the West Siberian Plain is approximately eight months in the north to about five months in the south. While the period of intense snow melting is short (one or two months between March and May), snow accumulation persists for most of the cold season. Snow accumulation is associated with negative anomalies of sea level pressure, which means increased cyclonal activity and weaker than normal Siberian High. Much lower anomalies of sea level pressure occur during snow ablation. This suggests smaller influence of air circulation on snow cover reduction in spring. [ABSTRACT FROM AUTHOR]