Impact of observed North Atlantic multidecadal variations to European summer climate: a linear baroclinic response to surface heating
Impact of observed North Atlantic multidecadal variations to European summer climate: a linear baroclinic response to surface heating
复制标题
DOI：
10.1007/s00382-016-3283-4
复制
发表时间：
2017-06-01
期刊：
影响因子：
4.6
通讯作者：
Bader, Juergen
中科院分区：
文献类型：
--
作者：
Ghosh, Rohit;Mueller, Wolfgang A.;Bader, Juergen
The observed prominent multidecadal variations in the central to eastern (C-E) European summer temperature are closely related to the Atlantic multidecadal variability (AMV). Using the Twentieth Century Reanalysis project version 2 data for the period of 1930-2012, we present a mechanism by which the multidecadal variations in the C-E European summer temperature are associated to a linear baroclinic atmospheric response to the AMV-related surface heat flux. Our results suggest that over the north-western Atlantic, the positive heat flux anomaly triggers a surface baroclinic pressure response to diabatic heating with a negative surface pressure anomaly to the east of the heat source. Further downstream, this response induces an east-west wave-like pressure anomaly. The east-west wave-like response in the sea level pressure structure, to which we refer as North-Atlantic-European East West (NEW) mode, is independent of the summer North Atlantic Oscillation and is the principal mode of variations during summer over the Euro-Atlantic region at multidecadal time scales. The NEW mode causes warming of the C-E European region by creating an atmospheric blocking-like situation. Our findings also suggest that this NEW mode is responsible for the multidecadal variations in precipitation over the British Isles and north-western Europe.
