A Comparison of Intermonthly and Interannual Teleconnections in the 700 mb Geopotential Height Field during the Northern Hemisphere Winter

Abstract

Abstract Intermonthly and interannual teleconnection patterns in the 700 mb geopotential height field during the Northern Hemisphere winter are computed by the method of digital filtering and spatial correlation analysis. A comparison of the teleconnection patterns of the intermonthly signal with the patterns described by Wallace and Gutzler shows that the western Pacific, western Atlantic and Pacific-North American patterns are clearly defined by the intermonthly signal; weak evidence for the eastern Atlantic pattern is also found. A northern Asian pattern, having one center over Mongolia and another over the Kara Sea near 70°N, 70°E, is also found to be a prominent feature of the intermonthly signal. The one-point correlation maps show that the spatial correlation function is dominated by the intermonthly band. The Pacific-North American pattern is well-defined in both the intermonthly and interannual bands. Three additional patterns—the North Pacific, the Eurasian and the zonally-symmetric seesaw—appea...