ATMOS: Atmospheric Sciences Information Resource
(Western Siberian Lowlands, Lake Baikal region)

Siberia and global climate

Siberia is a region almost equal in size to Europe, and a quarter of the entire area of Asia. It extends from the Urals in the west to the Okhotsk Sea coast in the east and from the Arctic Ocean in the north to the borders of Kazakhstan, Mongolia and China in the south.

The Siberian landscape is vast and, passing from north to south, changes from tundra to boreal forest to forest-steppe. Containing approximately half the world's boreal forest and the world's largest lowland - the Siberian plain - , it has an extreme continental climate and vast permafrost areas.

The extent of Siberia makes this region of the globe a particularly important actor of the global climate. Inversely, its sensitivity to changes in the water cycle makes it vulnerable to projected global climate changes. Moreover, local technical progress includes extraction and processing of mineral ore deposits and oil and gas resources, chemical metallurgy industries, extensive forest felling, development of large reservoirs for hydroelectric power stations and development of agriculture, transport and communication infrastructures, which all bring increased anthropogenic loads, pollution and warming to the permafrost regions.

Meteorological and ecological factors at stake include the relationships between the Siberian snow depth and the Asian monsoon, and the role of the permafrost-vegetation combination in driving the water cycle.

Siberian winter and the Asian monsoon

The Asian monsoon is a major component of the global energy and water cycle affecting the agriculture, economics and ecosystem of the entire Asian region including more than 60% of the world's population who live under its influence. There is a relationship between the depth of winter snow in Siberia and the amount of monsoon rain falling in the Asian monsoon. Above-normal winter snow depth over central Siberia, and the corresponding below-normal snow depth over European Russia, is associated with increased summer monsoon rainfall over southern and western India and eastern Pakistan, and below normal sea- surface temperatures over the eastern and central tropical Pacific Ocean during the following winter (Ye and Bao, 2001).

Permafrost, the boreal forest and the water cycle

The boreal forests of Siberia consist largely of larch trees that have adapted a specific root formation in order to survive in the permafrost regions. During a wet summer, the forest uses rainwater and the permafrost retains surplus water in the soil. In a severe drought summer, the permafrost is a direct source of water for plants (Sugimoto et al., 2002). Permafrost melting may, in the short term, result in improved soil nutrition in the areas the larch forests occupy, yet leave them vulnerable to an increase in the frequency of forest fires and damage by insects and pathogens during severe drought years. The consequences of projected global warming and technical advances could have serious consequences for Siberia: the larch forests and tundra zone may be reduced by up to 50% and grassland, scrubland and steppe will expand (Dixon et al., 1996; Kobak et al., 1996).

References

Dixon, R.K., O.N. Krankina, and K.I. Kobak (1996)
Global climate change adaptation: examples from Russian boreal forests. In: Adapting to Climate Change, Assessment and Issues [Smith, J.B., N. Bhatti, G.V. Menzhulin, R. Benioff, M. Campos, B. Jallow, F. Rijsberman, M.I. Budyko, and R.K. Dixon (eds.)]. Springer-Verlag, New York, NY, pp. 359-373.
Kobak, KI; Turchinovich, IY; Kondrasheva, NY; Schulze, ED; Schulze, W; Koch, H; Vygodskaya, NN. (1996)
Vulnerability and adaptation of the larch forest in eastern Siberia to climate change. Water Air And Soil Pollution. SEP 1996.
Sugimoto A, Yanagisawa N, Naito D, Fujita N, Maximov TC. (2002)
Importance of permafrost as a source of water for plants in east Siberian taiga. Ecological Research. JUL 2002.
Ye, HC; Bao, ZH.(2001)
Lagged teleconnections between snow depth in northern Eurasia, rainfall in Southeast Asia and sea-surface temperatures over the tropical Pacific Ocean. International Journal Of Climatology. NOV 15 2001


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