Effects of single- and double-moment microphysics schemes on the intensity of super typhoon Sarika (2016)

Abstract

Abstract The Weather Research and Forecasting (WRF) Double Moment (DM) 6-class (WDM6)/WRF DM 5-class (WDM5) and WRF Single Moment (SM) 6-class (WSM6)/ WRF SM 5-class (WSM5) microphysics schemes were selected to conduct four simulation experiments for super tropical cyclone (TC) Sarika (2016) using the WRF model. Both the SM and DM schemes had little effect on TC track, but there were significantly difference in TC intensity simulations. TC simulated by the SM schemes are stronger than that by the DM ones and are also closer to the observed. The SM and DM schemes affect TC intensity through its dynamic and thermal structures. TC simulated by the SM schemes has a smaller eye, a smaller radius of maximum wind (RMW), stronger tangential wind, closer latent heating area to TC center, higher positive temperature deviation in about TC center, and thus stronger TC. The latent heating rate of condensation in the SM schemes is higher than those of DM ones. The higher latent heating areas of condensation in the SM schemes are in the inner side of the eyewall and are significantly closer to the TC center and strengthen TC. On the contrary, the higher latent heating areas of condensation in the DM schemes exist within in the outer side of the eyewall and TC weakened. For the DM schemes, since equations predicting cloud water and rain water number concentrations are added, the production rates for autoconversion and accretion are also changed. The DM schemes have distinctly different cloud water and rain water distribution characteristics when compared with the SM ones.