Change in Yields of Cereal Crops in European Russia Caused by the Quasi-Biennial Oscillation of Atmospheric Processes

Abstract

The objective of work is to study the influence of quasi-biennial oscillation of atmospheric processes on precipitation and frequency of the spring-summer drought against the background of the statistics of cyclonic and anticyclonic activity in different phases of the quasi-biennial oscillation and, consequently, on the yield of wheat in the European part of Russia. The area of the study is the grain zone of European Russia including the North Caucasus, Central Chernozem zone, Volga region and Southern Urals. The timeseries of values of speed and direction of zonal wind on an isobaric surface of 30 hPa for the period 1953–2011 was accepted as data characterizing the “classical” quasi-biennial (Data of Free University of Berlin, https://climatedataguide.ucar.edu). Decadic precipitation totals, indices of PDSI and SPI, snow depth in March, the frequency of centers of cyclones during the period of vegetation classified by phases of quasi-biennial. The increase of snow depth in March is revealed, as well as significant increase in precipitation and a reduction in the frequency of severe droughts in May associated with the intensification of cyclonic activity during the Western phase in relation to Eastern on a vast territory: the western region of Central Chernozem zone, Rostov region and Krasnodar krai. As a result of changing agro-climatic conditions depending on the phase of the quasi-biennial in the territory, it is found a significant excess of productivity of spring wheat during the Western phase against the Eastern phase. The yield of winter wheat was less sensitive to the quasi-biennial. The results of the study can be used to adequately address the problem of increasing the sustainability of harvests in Russia (improvement of agrometeorological practice, including prognostic aspects, and agroinsurance).