The seasonal variation of stratosphere-troposphere mass exchange in 2000 year is diagnosed by Wei formula in pressure coordinate. The main results are as follows: (1) The west Pacific in the tropic is the main channel of the upward transport from the troposphere to the stratosphere with the obviously seasonal shift. The largest net flux from the troposphere to the stratosphere appears in autumn due to the weak of equator convergence belt in 2000. (2) The upward and downward transport of mass in the middle and high latitude accompany with each other. Downward transport from the stratosphere to the troposphere mainly appears near the large-scale trough. The stronger transport into troposphere appears in winter and spring, the weaker in summer and autumn. The seasonal variation of upward transport is consistent with the variation of the large scale circumfluent. (3) Strong downward fluxes of air mass from the stratosphere appear in eastern Asia. Although its area accounts 5.6% of the Northern Hemisphere (NH), the net exchange value reaches 29% of the total mass exchange in NH. This means the STE in the eastern Asia is important for the Northern Hemisphere.
Chinese Journal of Atmospheric Sciences
the Northern Hemisphere