Publication Date:
2015-03-13
Description:
This study assesses the ability of the 25 GCMs from phase 5 of the Coupled Model Intercomparison Project (CMIP5) to simulate Ural blocking (UB) and its linkage with the East Asian winter climate [December–February (DJF)] in a historical run (1950/51–2004/05). A Ural blocking index (UBI) is defined as the DJF-mean blocking frequency over 45°–90°E for each winter. Regression analyses suggest that the long-term mean bias of UBI is caused by the long-term mean circulation bias over the North Atlantic. On seasonal time scales, the GCMs simulating a positive bias of UBI are associated with a stronger Atlantic jet stream, as well as stronger westerly momentum fluxes from the North Atlantic to Europe. On synoptic time scales, however, these GCMs tend to be associated with a weaker Siberian high and East Asian trough during the evolution of a UB event. Altogether, there is no apparent linkage between the long-term mean bias of UB and the East Asian winter climate. Further studies are needed to explore the teleconnection between UB and the East Asian winter climate in the GCMs.
Print ISSN:
0894-8755
Electronic ISSN:
1520-0442
Topics:
Geography
,
Geosciences
,
Physics
