Factors in the model equations associated with spherical geometry have
been included in QTCM1 beginning with v2.0. However, in v2.0 through
2.2, these factors appeared only in the dx terms and were omitted
for instance in 
term in the divergence. These have now been corrected in v2.3.
The front-end subroutine for the fatd package have also been made
consistent for spherical geometry.
The 
term of the momentum
equation is
neglected since it would add computation of several additional terms
(such as 
, etc) and is small relative to 
especially
in the tropics.
The spherical factors are controlled in subroutine parinit. Array
cosu is the cosine factor at each ``whole
gridpoint'' latitude location, i.e.
where the u variable is defined on the C-grid
(Table 3.1). Array cosv is the same
at the ``half-grid'' locations, i.e. where the v variable is
defined on the C-grid. Arrays dxu, dxv, dyu,
and dyv contain the corresponding grid distances in spherical
coordinates. To remove spherical geometry effects, set both
cosu and cosv to 1.