Conservative CIP transport in meteorological models

In order to improve the model representation, we have implemented the CIP-CSLR in meteorological models. Real-case simulations and idealized tests were carried out on the Earth Simulator with atmospheric general circulation models that only the watervapor and liquid water were transported with the CIP-CSLR method. Numerical experiments show that the CIP-CSLR scheme substantially improved the model outputs for both pure advection tests and the long-term climate simulations. Reasonable tropical precipitation is shown with the CIP-CSLR scheme, which is largely improved in comparison with the original spectral method. Using the CIP-CSLR on a new grid (Yin-Yang) system, we also achieved conservative and more accurate results of passive tracer advection with relatively fewer grid points compared with the latitude-longitude grid. Without polar singularity, the splitting procedure of CIP-CSLR achieves promising transport in spherical geometry even if large Courant number is specified.