Variability Modes of the Winter Upper-Level Wind Field over Asian Mid-High Latitude Region

Abstract

In this study, the NCEP/NCAR reanalysis dataset was used to analyze the variability modes of the winter upper-level wind field over Asian mid-high latitude region. As shown by the results, the dominant variability modes of the winter upper-level wind field over Asian mid-high latitude region are characterized by the out-of-phase variation in the intensity of the subtropical and temperate jets over East Asia and the meridional shift of the subtropical jet axis, on interannual and multiannual scales, respectively. The first leading variability mode can be used as a good measure to represent the integral variation of atmospheric general circulation in Asian mid- latitude region. Composite analyses suggest that the first leading variability mode of the winter upper-level wind field is intimately related to the atmospheric circulation and temperature anomalies in the northern hemispheric mid-latitude region.

Keywords:

• East Asian subtropical westerly jet
• temperate jet
• variability mode