Uzbekistan and climate change problem
Climate
Uzbekistan is situated on the north border of sub-tropical and temperate climate zones. High level of solar radiation combined with relief peculiarities and atmosphere circulation forms continental type of climate, with significant seasonal and daily air temperature fluctations, long and hot summer, humid spring and unsteady winter.
Territory of the country is opened for invasion of different air masses. Atlantic and arctic air masses enter plains from the north, north-west and west. Intensive winter warming is caused by invasion of tropic air masses in warm sectors of south cyclones, which change to abrupt cold weather. Average air temperature in July changes along the territory from 260C on the north to 300C on the south of the Republic, maximal temperature reaches 47-490C. Average temperature in January lowers to -80C on the north and to 00 on the south, minimal temperature reaches -380c (Usturt Plato).
In summer above strong heated desert areas continental tropic air is formed, and it differs with its dryness. Rainfall level is very low (within 80-200mm/year), at that it has high changeability. Aral Sea doesn’t significantly exert on rainfall level, but humidity increasing is observed in narrow littoral zone.
Mountain foothills rainfall level rising. - On declines of mountain ranges, opened for humid air masses – up to 600-800mm and more.
Descendance of snow avalanches in mountains in spring is possible. Most intensive rains may cause appearance of mud flows.
Human activity influence on climate of Uzbekistan is the result of melioration and dryland degradation. In agricultural melioration zones and water reservoirs summer temperature lowers and air humidity rises. However, meliorated ground and oasis areas are much smaller, than the territory of deserts and drylands. That is the reason why their influence on regional climate is insignificant. The other factor of regional climate change is Aral Sea’s aquatory decreasing. Climate aridity increasing is observed within 100-250km.
Climate of Uzbekistan, as well as the climate of the whole planet is undergoing fluctations of decades’. The tendency of air temperature increasing is observed during last decades and it is connected with anthropogen increasing of greenhouse gas concentration in the atmosphere.
Main warming indicates in Uzbekistan and Central Asian region in whole are the followings:
- air temperature increasing (especially of night one);
- increasing of year’s hot period;
- increasing of high temperatures reiteration;
- decreasing of number of frosty days and days with snow cover;
- decreasing of mountains’ snow-glacier resources, enriching the rivers.