HR: 09:25h
AN: C11C-05    [Abstracts]
TI: Impact of Autumn Eurasian Snow Cover on Seasonal Prediction of Wintertime NAO
AU: * Ma, S
EM: shujie.ma@bjerknes.uib.no
AB: On the basis of observational data it is found that the influence of Eurasian snow cover on the wintertime NAO takes place in October. The broad anomalous Eurasian snow in Oct. is controlled by the simultaneously anomaly of extratropical large scale circulation. The preceding spatial distribution of snow variation plays an important role in foretelling the subsequent atmospheric transition to wintertime circulation. The subsequently seasonal adjustment of atmospheric circulation is important for the wintertime NAO variations through the strength and location variations of Azores High under autumn extensive snow over Eurasian continent. While under conditions with less than normal Eurasian snow cover, basically speaking the atmospheric remote response to anomalous thermal heating caused by positive snow-albedo feedback is the key for the NAO variations, except that tropical Pacific SST anomaly is strong enough to dominate the NAO behaviour. Part of the above results is tested by numerical simulations.
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 4215 Climate and interannual variability (1616, 1635, 3305, 3309, 4513)
DE: 4904 Atmospheric transport and circulation
SC: Cryosphere [C]
MN: Fall Meeting 2005