A POSSIBLE INFLUENCE OF THE POLAR NIGHT STRATOSPHERIC JET ON THE SUBTROPICAL TROPOSPHERIC JET

According to Nigam (1990), the first mode of his EOF analysis mainly represents variabilities in the zonal-mean zonal wind related to the displacement of the tropospheric subtropical jet. The present results of a lagged correlation analysis reveal that perturbations in zonal-mean zonal winds first occur in the stratosphere and then propagate into the subtropical troposphere. Numerical experiments with a general circulation model also indicate that the initial perturbations in the stratosphere can cause appreciable changes in the subtropical tropospheric jet.