Effects of Ice Clouds on Barotropic and Baroclinic Processes during TOGA COARE

Effects of ice clouds on barotropic and baroclinic processes TOGA COARE are examined through the analysis of budget of perturbation kinetic energy in the control and sensitivity two-dimensional cloud-resolving model simulations. The sensitivity experiment excludes ice hydrometeor and associated microphysical processes. The exclusion of ice clouds generally enhances baroclinic conversion from perturbation available potential energy and reduces barotropic conversion from perturbation kinetic energy to mean kinetic energy. The analysis of the root-mean-squared difference and linear correlation cofficient in budgets of control and sensitivity experiments reveals that while baroclinic conversion process plays a major role in budget difference, barotropic conversion processes show a significant modification in the tendency difference in perturbation circulations. Barotropic conversion term and tendency term are positively correlated in the mid and lower troposphere whereas they are negatively correlated in the upper troposphere. The differences in vertical transport of zonal momentum and barotroic conversion are positively correlated near the surface whereas they are negatively correlated in the mid and upper troposphere. The differences in tendency of vertical transport of zonal momentum and zonal flux of ice hydrometeor have the smallest root-mean-squared difference, indicating that the difference in zonal flux of ice hydrometeor accounts for the difference in tendency of vertical transport of zonal momentum.