Učënye Zapiski Kazanskogo Universiteta. Seriâ Estestvennye Nauki (Dec 2017)
Analysis of the long-term variations in precipitation and snow depth in the northeast of Russia during the period of 1966–2014
Abstract
The purpose of this study is to analyze the interannual variability of atmospheric precipitation and snow depth in the northeast of Russia (Chukotka Autonomous Okrug, Magadan Region, Eastern Yakutia) for the period of 1966–2014. The following tasks are set in accordance with the above purpose: to investigate the atmospheric precipitation regime, as well as its rates and nature of changes in it; to reveal the relationship between the precipitation regime and snow depth. The monthly amount of atmospheric precipitation registered at 26 meteorological stations during 1966–2014 and the snow depth measured daily at four stations (Ostrovnoe, Markovo, Magadan, and Omolon) during 1966–2012 are the source data (www.meteo.ru) for the research. All the initial series have been subjected to statistical processing. Linear trends have been constructed. Their significance has been estimated by the coefficient of determination (R2) at the confidence probability level of 95%. Correlation analysis of the atmospheric precipitation and snow depth has been carried out. All conclusions are based on the statistical results of the investigation. A tendency of decreasing annual precipitation over a larger area with the highest value in the east (up to 8 mm /10 years) has been revealed. A significant contribution to this reduction is made by the precipitation of warm seasons (spring–summer) with the exception of their almost widespread increase at the end of summer. In the winter time, the amount of precipitation is stable in the entire northeast of Russia (except the southern regions), especially since the middle of 1980s. The snow depth in the north and south of the territory increases steadily. Unstable declines have been found in the east. In the west, the values of snow depth remain almost unchanged. The nature of variations in the snow depth does not agree with that of changes in the amount of solid precipitation, especially in the west and the south of the territory. This is due to the multifactorial formation of the snow cover.
