The monthly averaged basic air current was approximately the barotropic instable condition which was measured by the meridionalgradient of absolute vorticity.
对于这个月月平均基本气流，进行正压不稳定度判据的检定，发现存在接近正压不稳定的条件。
2
The reversal of meridional temperature gradient over South Asia is mainly a result of subsidence.
造成南亚季风区经向温度梯度逆转的原因是下沉增温。
3
The change of meridional temperature gradient influences the strength of the mean meridional circulation and the westerly jets directly.