Long-term behavior of a GCM including large scale topography
包括大地形作用的大气环流模式的长时期性状

A series of experiments is performed to investigate the behavior of a twolayer general circulation model in long-term integration . Firstly , the adiabatic frictionless version of the model is run to study the response of a spherical free atmosphere to pure orographic forcing . The result shows that the ridges and troughs forced by the topography can not be maintained more than 20 days . Then some possible causes for that are studied by using diagnostic analysis . Finally , a zonally symmetrical diabatic heating and a simple friction are introduced into the model and a 150 day integration with the model is carried out. The analysis of time-averaged 500 hPa height reveals that the mountain-forced ridges and troughs still exist even in the last 15 days of the period . A phase analysis indicates that only the component with zonal wave number two seems to be quasi-steady , while the other components are transcient.