Major changes in QTCM1 V2.1 from V2.0:

1) Vertical profile of b1 (the first basis function of moisture perturbation from reference state) is changed to avoid negative moisture in the upper levels (see Neelin and Zeng 1999 p17). Corresponding radiative coefficients in clrad1.f are updated.

2) The meridional boundary of the model is stretchable up to the poles (model performance is sensitive to certain parameters when global domain is used). All grids are shifted a half-grid point in the meridional direction. So T and u points are located symmetrically about the Equator. Only v and vort0 points are on the Equator.

3) A slab mixed-layer ocean model is implemented (see manual for details). We use Q-flux correction for ocean transport. A generic routine aveflux.f is supplied for computing Q-flux from forced-SST simulations. Users can choose between rdsst.f and mxlayer.f for forced-SST, or mixed-layer coupled simulations.

4) Two additional convective closures are implemented in qtcm.f.mconvct2. One is the Betts-Miller scheme implemented without linearizing the Clausius-Clapeyron equation in the moisture closure (as was the case for the default version). It significantly improves simulations over mid-latitudes. The other is a convective closure based on boundary layer moist static energy. Results are similar to the default version (details are forthcoming in Su et al. 1999).

Minor changes:

1) utilities.f is created. It bundles most generic subroutines for various computations.

2) bndry.f is modified to read multiple monthly boundary data and also to conduct time interpolation into daily data.

3) Several makefiles for different machines (SUN,CRAY and SGI) are provided. A set of shell scripts for running QTCM on CRAY is also provided in /work.cray.

4) Original FirstTime.sh is renamed as spinup.sh.