: Research activity



According to results of the snow cover research, increase of snow storage and snow thickness on the most part of territory accompanies the modern warming in Russia. The largest increase in snow accumulation since the beginning of 1970s due to intensification of the zonal flows and cyclonic activity is observed north of 55 º N from the center of European Russia and the White Sea to the lower course of the Lena River. Mild winters and a decrease of precipitation in central and south-western regions (due to lower frequency of cyclones) result in decrease of snow cover in the north-west of the European part of Russia.

The study of snow accumulation in four large river basins (Volga, Ob, Yenisei and Lena) and its contribution to the variability of annual runoff showed that the increase in snow accumulation determines the increased runoff of the Volga and Yenisei rivers, and these trends are expressed weakly in the basins of Ob and Lena. Both trends of annual runoff in the basins of the Volga and Yenisei rivers and the increase in snow accumulation are related to increased occurrence of positive anomalies in the North Atlantic Oscillation since the middle of 1970s.

Zoning of Northern Eurasia is carried out using long-term changes of snow cover, winter and summer air temperature. Anomalies of snow accumulation and surface temperature are caused by variations of the same circulation mechanisms. Long-term fluctuations in winter temperature in Russia result from changes in global circulation by about 80%, and its extremes are associated with simultaneous anomalies of several circulation indices. Winter temperature trend since the beginning of 1970s is entirely described by changes in the North Atlantic Oscillation (NAO - 70%) and the Scandinavian pattern index (SCAND - 30%). The relationship between winter air temperature in Northern Eurasia and indices of global atmospheric circulation is nonlinear. Relative role of the mechanisms of circulation, responsible for changes in temperature, has changed since the mid- 1970s.
The consequences of climatic desertification in the arid regions of Russia in the second half of the 21st century have been identified. There are opposite tendencies of climate component of desertification in the situation of global warming: its weakening in the south-east of Russian plain and the intensification in the south-east of Western Siberia. Impact of both climatic and anthropogenic factors of desertification diminish in the late 20th - early 21st century in the south-east of Europe. Climatic preconditions of the desertification have increased in the steppes of the eastern part of Western Siberia and Altai. According to scenario of Regional Climate Model (RCM) of Voeikov Main Geophysical Observatory, increase in aridity is expected in the steppes of southern European Russia (Krasnodar Territory and Rostov Region) to the mid- 21st century and in the semi-desert, steppe and steppe landscapes to the end of 21st century.
Statistical analysis of the influence of different climatic factors on the characteristics of permafrost in the Western and Eastern Siberia have shown that spring air temperature determines the interannual variations of soil temperature at the depth of 3-10 m, and the temporal shift can be up to 2 years. The depth of summer thawing of permafrost is caused by anomalies in the summer and partially spring temperatures. Role of the snow cover depth fluctuations is detectable only under its large interannual variability.

Study of energy and water exchange on land continues the fundamental geographic research of A.A. Grigoriev, M.I. Budyko, Y.L. Rauner and others. Universal indicators of spatial-temporal organization of energy and water exchange on land were developed. Critical scales of space and time, exceeding of which leads to loss of information on the variability of energy and water exchange during averaging, have been identified. Indicator of the ratio of heat and water resources, taking into account seasonal variation and the processes in snow cover, has been developed. Differences in the regional structure of the energy and water exchange were estimated using the indicator. Increase of water resources exceeds that of heat in the equivalent units in most of Northern Eurasia under the contemporary climate change. This change results in a shift of the zone of insufficient moistening to the south.

Methods of differentiation of regions and countries according to the influence of cold on the humans to estimate the cost of vital energy expenditures has been proposed. Indicator for various countries and regions of the Russian Federation has been developed and evaluated. Indicator can be used in the calculation of national quotas for greenhouse gases.

Zoning of the Russian Federation on natural conditions of the human life was made. Zoning allows for negative (positive) influence of environment on the human health, life and activity and takes into account the impact of the major environmental factors: cold, heat, humidity, altitude, natural hazards (meteorological, seismic, permafrost). Evaluation of changes of climatic conditions for the population in European Russia and Western Siberia in the mid-21st century (2041-2050) using the results of Regional Climate Model was made. Map Zoning of the territory of Russia by natural life conditions (1:45000000 scale) is published in the National Atlas of Russia. Maps Extremeness of climatic conditions for population life (1: 20000000 scale) in the National Atlas of Russia and Zoning on combination of climatic extremes (1:3000000 scale) in the Atlas of natural and technogenic dangers and risks of the emergency situations are developed and published.

Daily calendar of elementary circulation mechanisms (ECMs) for Northern hemisphere according to B.L.Dzerdzeevsky method is continued at the Laboratory. More information see at the website http://www.atmospheric-circulation.ru.

Combination of climatic extremes in the territory of Russia and their spatial and temporal shift due to the changing climate. Zoning of the territory of Russia on a combination of climatic extremes for the period 1986-2000 was done. The spatial shift of the areas of different combinations of climatic extremes, compared with zoning based on data for the period before 1986 was studied. Summer conditions became milder due to reducing the area with combination of extreme heat, intense precipitation and strong winds in the south of the Russian Plain. Decrease of the area of the annual average absolute minimum temperature (less than or equal to -40 grad C and -50 grad C) occurred in Siberia. Two areas with combination of all four types of extremes - the summer heat, the cold winter, intense monsoon precipitation and strong wind - were identified in the south-east of the Chita Region and the south-west of the Amur region.
Justification for the natural boundaries in the Arctic as a physical-geographical area was done for determination the southern boundary of the Russian Federation Arctic zone.
Dynamic downscaling of the meteorological fields for selected regions of Russia was done based on the results of the model MM5. It was shown that the dynamic downscaling of fields using a regional model is possible for small territories. Comparison of the fields, interpolated by mathematical methods and modeling data showed that the use of a regional model has the advantage over other methods. Increase of the area of averaging reduces the differences between model results and observations. MM5 reliably reproduces the information on the spatial scale of about 100 km and on averaging timescale of one day and a discrete grid 15x15 sq km. MM5 is able to reproduce the geographical distribution of meteorological anomalies. It is possible to forecast atmospheric drought and flood in small rivers using the dynamic downscaling of the meteorological fields.
The investigation of climatology of natural transition zones of Russia was done. Zonal contrast of indices of climate and radiation heat flux increases in the north-east and south-east of the Russian Plain. This change causes the maximum contrast of the canopy indices in the transition zones - forest-tundra and semi-desert. Zones of maximum meridional gradient of climate and radiation heat fluxes are located not only in the forest-tundra and semi-desert zones, but also extend to adjacent areas (subzones).
Influence of volcanic eruptions of the XX century on the regime of precipitation was investigated in the territory of Russia. Largest gas and ash eruptions of the 20th century with the emissions reaching the lower stratosphere impact the precipitation in the cold and warm seasons. Increase in precipitation during the cold period is observed after volcanic eruptions in the second half of the 20th century. In most cases, extreme precipitation events were observed.
Dynamics of moistening of Subboreal plain landscapes of Russia. Moistening of Subboreal landscapes increased to the early 1990s, then a downward trend is observed. Positive trend of moistening retained in the semi-desert landscapes, forest-steppe and steppe in the south of Western Siberia. Increased moistening of Subboreal landscapes in the second half of the 20th century was insufficient for the occurrence of climatic preconditions of shift of the arid zones boundaries. Arid zones boundaries were steady and remained within interannual variability during the period.