摘要
This is one part of the series study on the forcing of waves on basic flow, in which theannual variations of E- P cross section are used to compare the wave- mean flow interactionsin the Northern and Southern Hemispheres. Results show that in either hemisphere, wave-meanflow interaction is very strong in winter, and very weak in summer. External forcing sourcefor planetary waves in the Southern Hemisphere appears to be rather weak not only in summer,but also in winter. It is pointed out that in the troposphere. since the mass circulation isstrong, and since the static stability is small, in the dynamic equation, the inertial effect ofthe residual circulation becomes important in balancing that of the E- P flux divergence.Therefore, when the westerly acceleration in the troposphere is studied, both terms of E-Pflux and residual circulation should be considered. It turns out to be more convenient to usethe conventional Euler system to investigate the direct contribution of eddies to the meanflow.
This is one part of the series study on the forcing of waves on basic flow, in which the
annual variations of E- P cross section are used to compare the wave- mean flow interactions
in the Northern and Southern Hemispheres. Results show that in either hemisphere, wave-mean
flow interaction is very strong in winter, and very weak in summer. External forcing source
for planetary waves in the Southern Hemisphere appears to be rather weak not only in summer,
but also in winter. It is pointed out that in the troposphere. since the mass circulation is
strong, and since the static stability is small, in the dynamic equation, the inertial effect of
the residual circulation becomes important in balancing that of the E- P flux divergence.
Therefore, when the westerly acceleration in the troposphere is studied, both terms of E-P
flux and residual circulation should be considered. It turns out to be more convenient to use
the conventional Euler system to investigate the direct contribution of eddies to the mean
flow.
基金
Medium range numerical weather forecast project [75-09-01]
This study is partly supported by Chinese National Natural Science Foundation under the project number 4860205
belongs to the National Research Project of medium range NWP [75-09-01].
