Intercomparison of global tropical cyclone activity using four cumulus parameterizations in tropical channel climate simulations

This paper explores the effect of cumulus parameterization schemes (Kain-Fritsch (KF), Betts-Miller (BM), Grell-Devenyi (GD) and Grell 3D (G3D)) on global tropical cyclone activity in year-long simulations using the Advanced Research WRF model (v3.1.1). The horizontal grid spacing is about 20 km around the equator; the domain spans 60°S–60°N in latitude and has periodic boundary conditions in the east-west direction. Forcing data for the northern, southern and lower (sea surface temperature) boundary conditions are obtained from the ECMWF ERA-Interim Reanalysis (T106). Simulated tropical cyclone activity for the year 2004 for each cumulus parameterization is compared to observations (TRMM 3B43 and IBTrACS). First, we compare the model precipitation patterns with TRMM, and show that GD scheme predicted the precipitation pattern over tropical regions best. Second, a TC tracking method was developed and applied to evaluate the TC activity over each of the TC basins. We show that KF outperformed other schemes in terms of TC genesis and developments when compared to IBTrACS. Physical interpretations for the differences will be discussed.