Previous: Results and Discussions Next: References Up: Ext. Abst.

Summary

Presence of a stationary wave train extending from troposphere to the lower stratosphere is detected during the month of May. This wave is prominently seen below 70 hPa level, has a zonal wave number of 6 or 7 and is generally confined between 10° N and 50° N. In the lower stratosphere, the wave shows a phase shift of 20° longitude between good and bad monsoon years. Amplitude of this wave is maximum around 200 hPa and decreases both upward and downward. The large amplitude portion of the wave is thus situated in the tropopause break region between tropics and sub-tropics and is found to exchange tropical and sub-tropical air masses through the tropopause break.