|Climate change trends and scenarios|
|<< CHANGES IN AIR TEMPERATURE >>|
|The greatest changes in the climate, in
particular in the temperature regime, have taken place in areas affected by human
intervention into environment: urbanization, land development, construction of reservoirs,
So, general warming in the 1930-40-s, as a whole, hasn't had an effect on climate change in the republic. In the following decade, a decrease in the temperature condition was observed, and the mid-1950s were one of the coldest periods in the history of instrumental observations in Tajikistan. At that time, the temperature on average was 1-1,5°C lower than normal.
In light of the fact that remarkable changes began to be observed in the climate since the 1960s, and that comprehensive meteorological observations had been carried out in Tajikistan also in this period, this summary considered every aspect of the annual and seasonal temperature of air for that time.
During 1961-1990, an increase of 0,7-1,2°C in the annual mean air temperature was observed in the wide valleys of Tajikistan. To a lesser degree, the growth of temperature had taken place in mountainous and high-altitude areas (by 0,1-0,7°C), and only in the mountains of Central Tajikistan, Rushan and low reaches of Zeravshan was there a small decline in temperature of 0,1-0,3°C.
In large cities, the growth of near surface temperature was especially significant and reaches 1,2-1,9°C that, obviously, is associated with urbanization (construction of roads, buildings, transport, industry, etc.).
In zones with irrigated agriculture, such as the newly irrigated Yavan valley, the temperature tended to decrease, especially in summer. In the south (Shaartuz) and north (Khujand) of the republic, the annual mean air temperature has remained the same, which is conditioned by local factors (land development, construction of a water reservoir).
During 1961-1990, the warmest year was 1971, when the annual mean air temperature everywhere exceeded the norm by 0,7-0,8°C. The following year, 1972, was the coldest in this period, when the negative deviation of the temperature was 2°C from valley to foothill zones, and 1-1,3°C at high altitudes. Eastern Pamir was exception, where the coldest year was 1965, when the mean air temperature was 1,2-3,4°C lower than normal.
Among the coldest periods was 1964-1969, when the mean temperature was lower than multiyear mean values by 0,2-0,9°C in valley and foothill areas (in the south 1,1°C and in Khujand). In the mountains and high altitudes, the decline averaged to 0,3-1,1°C, and in Eastern Pamir to 0,1-3,4°C.
The warmest period was seen from 1977 to 1984 and in lowland areas until the 1990s. The temperature at this time exceeded norms by 0,6-1,6°C.
During the period under investigation, the greatest increase in temperature has been observed for the autumn and winter season, by 0,6°C in valleys, and by 0,7°C in mountains. In the spring and summer season the rise in the temperature of air all over the republic has averaged within the range of 0,1-0,4°C.
The winter period is characterized by an increase in temperature, except for the low reaches of Zeravshan, Kuliab, Yavan valleys and eastern part of the Pamirs, where it has decreased by 0,1-0,4°C. The greatest increase in the winter temperature is observed in Dehauz, Faizabad and Maikhura, as well as in large cities.
The spring temperatures in Tajikistan, in general, tend to increase in lowlands, mountain and high-altitude areas by 0,2-0,7°C. In a number of foothill areas and irrigated valleys, as well as partly in Pamirs the temperature decline of 0,1-0,7°C has been observed.
In summer, maximum annual temperatures are usually observed in Tajikistan. In lowland and foothill areas, a tendency of growing summer temperatures by 0,2-0,8°C manifests itself. Only in the mountains of central Tajikistan, a small downward change in temperature of 0,4°C, and in the south of the republic (Shaartuz) of 0,3°C has been observed.
The autumn temperatures, as a whole in the republic, tend to a significant average growth of 0,8-1,2°C, particularly in the south and east of the country. Central Tajikistan is probably an exception, as in a number of areas a downward trend has been observed.
Since the 1990s, the programme and volume of meteorological observations in Tajikistan have decreased considerably. Nevertheless, the available data allow the assertion that the 1990s appear to be the warmest in the history of the instrumental observations in Tajikistan, particularly in 1997. In 2001, the record maximum temperatures have been registered.
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