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Changes in the Relationship Between the Interannual Variation of Eurasian Snow Cover and Spring SAT Over Eastern Eurasia
Author(s) -
Wang Min,
Jia Xiao Jing,
Ge Jing Wen,
Qian Qi Feng
Publication year - 2019
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1029/2018jd029077
Subject(s) - climatology , arctic oscillation , snow , atmospheric circulation , atmospheric sciences , environmental science , arctic , advection , baroclinity , geology , northern hemisphere , oceanography , thermodynamics , physics , geomorphology
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.