2010 Volume 6A Issue SpecialEdition Pages 21-24
Substantial change was found in the El Niño/Southern Oscillation (ENSO) teleconnection during the boreal winter after the regime shift of the late 1970s. The ENSO teleconnection pattern of the earlier period is characterized by a wave-train-like structure over the Pacific/North American sector that also propagates into the stratosphere. In contrast, the recent ENSO-related extratropical circulation anomalies are characterized by changes in the tropospheric subtropical jet. The interaction of zonal winds with large-scale topography creates meridional dipole-type height anomalies downstream of the Rockies and the Tibetan Plateau, which may characterize the recent ENSO teleconnection pattern.