Present climate development in Southern Siberia: a 55-year weather observations record

Abstract

Siberia is a key region for study of the climate development in north-central Eurasia in terms of global climatic change. The relief creates a major orographic barrier for atmospheric streams influencing the regional altitudinal weather zonality. Systematic 55-year (1963-2017) weather observations along the 700 km N-S latitudinal transect across the southern Siberian plains and the adjoining ranges of the Altai-Sayan Mountains document progressing seasonal temperature and humidity shifts. Standard meteorological data from twenty meteorological stations in different topographical and natural settings with specific weather conditions document a rise of a regional atmospheric humidity balance reflected by the increased bulk annual precipitation rates in the mountain areas accompanied by pronounced seasonal air-temperature fluctuations. This regionally trend provides evidence speaking in favor of the strengthening climate continentality over Siberia, which is also manifested by the pronounced seasonal temperature regime with increased thermally positive and negative air temperature anomalies. A landscape response to a climate warming is particularly evident in the high mountain zone. The present thermal conditions with raised MAT contribute to the progressing melting of mountain glaciers and degradation of permafrost in the alpine zone, as well as aridization of the parkland-steppe areas that are being partly transformed into continental semi-arid to deserted steppes. The associated environmental transformations trigger shifts in the local biotopes and ecosystems, with an altitudinal expansion of taiga-forest into the alpine tundra belt and xerothermic grassland invasions in the foothills. The modern climate changes have a major bearing to the Altai-Sayans socio-economic development.