Changes in the Relationship Between the Interannual Variation of Eurasian Snow Cover and Spring SAT Over Eastern Eurasia

Changes in the relationship between interannual variation of spring (March–April–May) surface air temperature (SAT) over eastern Eurasia (SAT_EA) and Eurasian snow during 1972–2009 are investigated. The results show that the interannual variation in SAT_EA is significantly correlated with Eurasian snow cover anomalies (SCA) over two key regions, which include the western (SCAW) and eastern (SCAE) parts of the Eurasian continent. A pronounced climate shift of SAT_EA is observed around the late 1980s, and therefore, the data are divided into two subperiods, that is, 1972–1987 (P1) and 1988–2009 (P2). Examinations show that the relationship between SAT_EA and SCAW is impacted by the Arctic Oscillation. In contrast, the relationship between SCAE and the SAT_EA is Arctic Oscillation independent and is significantly increased from P1 to P2. Further analysis shows that the increased correlation between SAT_EA and SCAE from P1 to P2 cannot be well explained by the snow‐related surface heat flux. A wave train‐like anomalous circulation plays an important role in enhancing their relationship through intensified wind‐induced heat advection in P2, which causes reduced snow and increased SAT_EA. A lead‐lag regression analysis of the SCAE and the circulation anomalies indicates that the changes of the SCAE and SAT_EA are mainly responses to atmospheric circulation anomalies that occur 2 months before spring. Numerical experiments that use a linear baroclinic model indicate that the snow anomalies around Lake Baikal may impact the variation of SAT_EA through modulating atmospheric circulation over the East Asia‐North Pacific area.