THE EFFECT OF MERIDIONAL CIRCULATION ON THE PROPAGATION OF STATIONARY ROSSBY WAVES

In general baroclinic atmosphere, when the basic state includes meridional circulation. the stationary waves might not only pass through the equatorial easterlies, but also strengthen significantly. And the orographic forcing in Northern Hemisphere midlatitude might cause marked responses in low latitude atmosphere. This suggests that the meridional circulation play an important role in the connection of stationary responses in midlatitude and low latitude as a result of heating forcing in Northern Hemisphere midlatitude. The features sim- iliar to Northern Hemisphere summer monsoon circulation can be obtained. It appears that the meridional circulation play some roles in the forcing of summer monsoon circulation. The anomaly forcing locating at the eastern equatorial Pacific makes the stationary waves present PNA pattern in Winter Hemisphere, but it does not in Summer Hemisphere. It suggests that the meridional circulation has a marked influence on the route of stationary waves propagation in Winter and Summer Hemisphere.