南极涛动异常及其对冬春季北半球大气环流影响的数值模拟试验

Simulation of the AAO anomaly and its influence on the Northern Hemispheric circulation in boreal winter and spring

利用IAP9L-AGCM模式考察了模式中与南极涛动异常相关的海温敏感区,发现南半球高纬海温异常能够强迫出南极涛动异常,而赤道东太平洋海温异常与太平洋南美型密切相关.研究了南极涛动异常对冬春季北半球大气环流及亚洲北部气温的影响,结果表明,南极涛动加强,能够引起北半球高纬环流异常和欧亚西风加强,以及亚洲北部地表气温和850hPa气温显著增温.数值模拟支持了已有的诊断结果,也证实了冬春季节南极涛动异常下两半球高纬间的经向遥相关存在.

AAO anomaly and its influence on the Northern Hemispheric circulation and temperature over north of Asia are studied by analyzing the output of IAP9L - AGCM model. First, Sea temperature associated with Antarctic Oscillation （AAO） is investigated using IAP9L- AGCM model. The model simulation shows that the sea temperature at high latitude in SH may cause the AAO anomaly and the east tropical Pacific ocean is closely related to Pacific Southern America （PSA） teleconnection. Second, the results show that positive AAO tend to enhance Eurasian west wind and circulation anomaly at high latitude in NH, resulting in the increase of both surface temperature （SAT） and temperature at 850 hPa over North Asia during the boreal winter and spring. The meridional teleconnection responsible for possible mechanism is pronounced in the simulation. Therefore, model simulation supports our previous observations.