ИСТИНА

Main features of climatic changes in Moscow city are discussed. Total tendencies of three meteorological parameters have been analyzed in details: air temperature, water vapor pressure and relative humidity. All available data received in past have been collected by authors – since 1779 till nowadays for the air temperature and since 1870 till nowadays for humidity parameters. As a result, three main changes of a sign of the air temperature T total tendency took place there during last two and quarter centuries. Firstly, probable increase of the T annual values at the end of the XVIII century (i.e. at the end of Little Ice Age) was followed by a fall of them at the beginning of the XIX century. Secondly, this fall was followed by long steady increase since the end of the XIX century. Thirdly, this warming seems to become a bit slower in Moscow during several last decades. Unlike air temperature, the water vapor pressure remains nearly the same (from 7 to 9 hPa in average of a year) and doesn’t demonstrate any statistically meaningful changes during last 140 years in Moscow (see Fig.1). At the same time, as a consequence of steady warming, the relative humidity becomes significantly less. At the end of the XIX century annual values of this parameter were nearly of 80 % whereas now they fell up to values from 70 to 75 %. Thus, climate of Moscow gradually becomes not only warmer but as well drier than before. Besides, an influence of the urban ‘heat island’ is analyzed as well by use of data received in Moscow region outside the city.