Evaluation of Air–Sea Flux Parameterization for Typhoon Mangkhut Simulation during Intensification Period

Abstract

Using the Advanced Research Weather Research and Forecasting (WRF) model, a series of numerical experiments are conducted to examine the sensitivity of the Typhoon Mangkhut intensification simulation to different air–sea flux parameterization schemes (isftcflx option), including option 0 (OPT0), option 1 (OPT1), and option 2 (OPT2). The results show that three schemes basically reproduce tropical cyclone (TC) track and intensity of observation, and the simulated exchange coefficient of three schemes is consistent with theoretical results. Using the same upper limit of Cd as OPT0 and OPT2, OPT1 has much larger Ck than the other two options, which leads to larger latent heat (and sensible heat) flux and produces stronger inflow (within boundary layer) and updrafts (around eyewall), and thus stronger TC intensity. Meanwhile, the results that larger Ck/Cd corresponds with stronger TC in the mature stage are consistent with Emanuel’s potential intensity theory. The fact that Ck in OPT1 is evidently larger than the Ck from previous studies leads to produce a better TC intensity simulation. Generally, we should use more reasonable air–sea flux parameterization based on observation to improve TC intensity simulation.