On the Mechanism of Summertime Atmospheric Anomalies Induced by External Forcing
外强迫引起的夏季大气环流异常及其机制探讨

By using a perpetual July, nine level general circulation spectral model with rhomboidal truncation at wavenumber 15 incorporated a comprehensive set of physical processes, a series of numerical experiments have been conducted to determine the mechanism of atmospheric anomalies induced by external forcing such as anomalies of the sea surface temperature and Arctic sea ice cover during the Northern Hemisphere summer. It is shown that the leading anomaly patterns observed in real atmosphere can be produced by external forcing. However, the patterns are insensitive to the positions of external forcing, but depend strongly on the internal dynamics of the atmosphere especially on the structure of the basic flow. There exist two kinds of mechanisms to interpret the role of external forcing on the atmospheric anomalies, of which the interaction between external forcing and internal atmospheric dynamical processes is a very important aspect.