The numerical model utilized here is
the same as that of
et al. (1998),
of the GFD-DENNOU CLUB edition
that is based on the three-dimensional primitive system on a sphere.
The horizontal resolution is T42
(truncated at wavenumber 42),
and the number of vertical levels is 16.
The cumulus parameterization is convectiv adjustment (Manabe et al., 1965).
The longwave absorption is represented by three bands of water
vapor and one band of dry air.
The absorption coefficients are empirically
chosen so that the cooling profile of the atmosphere
roughly resembles the observed one.
Scattering of longwave radiation,
scattering by clouds,
absorption/scattering of shortwave radiation
are not included.
The vertical mixing is represented by the level II scheme of
Mellor and Yamada (1974).
The surface fluxes of momentum, heat and water vapor are
evaluated by the bulk formula.
The distribution of SST is fixed and given
in the same way as that of Hosaka et al. (1998);
A warm SST area is placed at the equator centered at 180E
of a sphere covered with an SST distribution symmetric
around the equator and zonally uniform (Figure 1).
The shape of the warm SST area is a rectangle
with the longitudinal and latitudinal extents
of 40 degree and 20 degree, respectively.
The value of temperature of the warm area is the highest
at the center and gradually decreases toward the edge.
On the actual grid point,
it is 3.4K higher than the surroundings.
Figure 1: Horizontal distribution of SST (left panel)
and latitudinal profile of SST (right panel). Unit is K.
Dashed line and solid line in the right panel indicate
the basic profile and the profile
at the centered longitude of the warm SST area, respectively.