Dynamics and energy balance of the Hadley circulation
and the tropical precipitation zones. Part II:
Sensitivity to meridional SST distribution.
Numaguti, A., 1995b,
J. Atmos. Sci., 52, 1128-1141.
Abstract
A series of GCM experiments is performed
in order to examine the dynamics of the
time-averaged distribution of precipitation
and Hadley circulation in low-latitude area.
As an extension to Part I of this study (Numaguti, 1993),
the sensitivity to the latitudinal distribution
of the globally prescribed sea surface temperature (SST) is examined.
When the peak of SST is not at the equator but nearby,
a single precipitation peak appears on the opposite side of the equator.
When the latitude of the SST peak becomes high enough (about 15 degrees),
an abrupt jump of the precipitation peak is observed.
This behavior is completely different
if the evaporation from the ocean is estimated
independent of the surface wind speed.
Factors controlling the latitude of the precipitation zone are discussed.
It is found that one essential component
is the convergent flow in the planetary boundary layer
which is driven by the SST gradient.
Another important factor is the net moist static energy input
into the atmosphere, which is the difference between the
energy input from the surface and the radiative loss.
The near neutral stratification of the atmosphere,
which may be partially determined by the distribution of the SST,
is also considered to be important because
it controls the moist static energy balance of the atmosphere.