1957 Volume 35A Pages 280-288
Some attempts are made to produce prognostic charts at the 300 or 400 mb level, using the same method as we used in the previous paper (1). In this method the divergence term is included in the vorticity equation, in order to take into account the baroclinity.
The result shows that the divergence term and the height of the tropopause are important because the divergence which is derived from vertical distribution of vertical velocity is affected by abrupt change of stability near the tropopause.
In the stratosphere, the atmosphere becomes fairly barotropic, but near the tropopause level divergence term must be considered. The correlation between the observed and calculated height changes including the divergence term is fairly better than in the case of barotropic model.