East Asia and Western Pacific METEOROLOGY AND CLIMATE

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On the basis of the preceding discussion, there are two computational
processes in each time step.
The first is to obtain the cloud variation
caused by advection and the corresponding cloud-radiative heating.
The second
is to derive a new balanced state due to the variation in cloud-radiative
heating.
In general, the convective and stratiform condensations are included
in the balanced equation.
The solution of the balanced equations in the
second step may not be straightforward.
However, the diabatic geostrophic
balance can also be obtained from the adjustment process.
3. Results and Conclusion
From the numerical results, we find that if large-scale cloud-radiative
heating occurs in the equatorial region, the diabatic-geostrophic balanced
motion has a number of basic features.
These include a Walker and an anti-
Walker circulation with different characteristic horizontal scales developed
to the east and west, as well as two Hadley cells developed to the north and
south of the equatorial heating region.
An area of upper tropospheric
divergence is generated over the heating region, while an area convergence is
located at a distance of about 90-100° longitude to the east of the heating
region.
Anticyclone dipoles occur in the upper tropospheric stream function
field on both sides of the equator.
Their centers are located close to the
west of the equatorial heating center.
A high pressure region and zonal
westerlies are developed in the upper troposphere over the equatorial heating
center.
A broad easterly and a relatively narrow westerly are produced in the
lower troposphere to the east and west of the diabatic heating, respectively.
The zonal current in the upper troposphere over the center of the cloudradiative
heating region is about 4 m/s.
Thus Eq. (7) may be rewritten in