Atmosphere 2019, 10, 11; doi:10.3390/atmos10010011
Changes in the Atmospheric Circulation Conditions and Regional Climatic Characteristics in Two Remote Regions Since the Mid-20th Century
Maria G. Lebedeva 1, Anthony R. Lupo 2,* Yury G. Chendev 1, Olga V. Krymskaya 1 and Aleksandr B. Solovyev 1
1 Belgorod State National Research University, 85 Pobeda St., Belgorod 308015, Russian Federation; [email protected] (M.G.L.); [email protected] (Y.G.C.); [email protected] (O.V.K.); [email protected] (A.B.S.)
2 Atmospheric Science Program, School of Natural Resources, University of Missouri, Columbia, MO 65211, USA * Correspondence: [email protected]; Tel.: +1-573-489-8457
Received: 25 August 2018; Accepted: 14 December 2018; Published: 3 January 2019
Abstract: A meridional Northern Hemisphere (NH) circulation epoch, which began in 1957, is marked by changes in the temperature and precipitation regimes over southwest Russia and central USA depending on the occurrence of NH atmospheric circulation regimes. A classification scheme proposed in 1968, and studied later put forth 13 NH circulation types, fitting more broadly into four groups, two of which are more zonal type flows and two of which are more meridional flows. Using the results of a previous study that showed four distinct sub-periods during the 1957–2017 epoch, the temperature and precipitation regimes of both regions were studied across all seasons in order to characterize modern day climate variability and their suitability for vegetation growth. Then the Hydrologic Coefficient, which combined the temperature and precipitation variables, was briefly studied. The most optimal conditions for vegetation growth, positive temperature and precipitation anomalies, were noted during the period 1970–1980 for southwest Russia, which was dominated by an increasingly more zonal flow regime in the Belgorod region and NH in general. For the central USA, the HTC showed more ideal conditions for agriculture in recent years due to favorable precipitation occurrence. In southwest Russia, variable precipitation regimes were noted during the meridional flow periods, and with the increase in temperature (since 1998), these can adversely affect the hydrothermal characteristics of the growing season. Finally, a comparison of the 13 NH circulation types with several teleconnection indexes demonstrated the robustness of the NH flow regime classification scheme used here.
Keywords: climate change; circulation epochs; climate anomalies; hydrothermal coefficient; teleconnections