北半球大气遥相关型与区域尺度大气扰动

北极涛动(AO)、北大西洋涛动(NAO)和太平洋-北美型(PNA)等北半球大气遥相关型,可以用大气位势高度的物理分解扰动分量解释.结果发现,AO反映的是北极地区行星尺度纬圈平均扰动分量的变化,PNA与持续性天气尺度扰动分量相联系,NAO是行星尺度纬圈平均扰动与天气尺度扰动共同作用的结果.对行星尺度纬圈平均扰动分量和天气尺度扰动分量用旋转经验正交函数(REOF)展开,不但可以证实人们已经命名的区域性大气涛动,还新发现了北极地区的两对偶极涛动、欧亚涛动(EAO)和"大西洋-欧亚型"(AEA)波列.这些涛动连接了相邻地区的异常天气和异常气候.

Atmospheric teleconnections and regional-scale atmospheric anomalies over the Northern Hemisphere

Atmospheric teleconnections in the Northern Hemisphere such as Arctic Oscillation(AO),North Atlantic Oscillation(NAO) and Pacific-North American(PNA) teleconnection can be explained by the physical decomposition of geopotential height.The result shows that the AO reflects planetary-scale zonal-mean anomalies in the Arctic region;the PNA results from persistent regional-scale atmospheric anomalies;NAO is a combined result of both planetary-scale zonal-mean and regional-scale anomalies.The rotated empirical orthogonal function(REOF) of planetary-scale zonal-mean and regional-scale anomalies not only confirms the already known regional oscillations and wave trains,but also discovers new patterns,such as "twin dipole oscillations" in the Arctic region,Euro-Asia Oscillation(EAO) and Atlantic-Euro-Asia(AEA) wave-train pattern.These oscillations or wave trains are linked to adjacent regional weather anomalies and climate anomalies.