Decadal variability in the impact of atmospheric circulation patterns on the winter climate of northern Russia
The Arctic continues to warm at a much faster rate than the global average. One process contributing to ‘Arctic amplification’ involves changes in low-frequency macro-scale atmospheric circulation patterns and their consequent influence on regional climate. Here, using ERA5 reanalysis data, we examine decadal changes in the impact of seven such patterns on winter near-surface temperature (SAT) and precipitation (PPN) in northern Russia and calculate the temporal consistency of any statistically significant relationships. We demonstrate that the 40-year climatology hides considerable decadal variability in the spatial extent of such circulation pattern-climate relationships across the region, with few areas where their temporal consistency exceeds 60%. This is primarily a response to the pronounced decadal expansion/contraction and/or mobility of the circulation patterns’ centers of action. The North Atlantic Oscillation (NAO) is the dominant pattern (having the highest temporal consistency) affecting SAT west of the Urals. Further east, the Scandinavian (SCA), Polar/Eurasia (POL) and West Pacific patterns are successively the dominant pattern influencing SAT across the West Siberian Plains, Central Siberian Plateau and mountains of Far East Siberia, respectively. From west to east, the SCA, POL and Pacific North American patterns exert the most consistent decadal influence on PPN. The only temporally invariant significant decadal relationships occur between the NAO and SAT and the SCA and PPN in small areas of the North European Plain.
Authors: Marshall, Gareth J. ORCID record for Gareth J. Marshall