Effects of various combinations of boundary layer schemes and microphysics schemes on the track forecasts of tropical cyclones over the South China Sea

Shumin Chen,Yu-Kun Qian,Shiqiu Peng

doi:10.1007/s11069-015-1697-7

Abstract

This study investigates the effects of various combinations of the planetary boundary layer (PBL) schemes and the microphysics schemes on the numerical forecasting of tropical cyclones (TCs). Using different combinations of three PBL schemes (YSU, MYJ and MYNN2) and four microphysics schemes (Ferrier, Goddard, WSM6 and Lin), a number of experiments are carried out for five landed TCs in the South China Sea during 2012. Results show that the combination of the YSU and Ferrier schemes performs the best for the TC track forecasting, although it does not perform the best for the forecast of precipitation. Further analysis reveals that the best performance of the track forecast by the combination of the YSU and Ferrier schemes mainly attributes to a more accurate steering flow as well as TC wind structure produced by this combination. These results provide a valuable reference to the operational numerical forecasting of TC tracks in the future.

Highlights

Tropical cyclones (TCs) are one of the most destructing natural hazards (Emanuel 2005; Peng et al 2014) and pose great scientific challenges to meteorologists
This study investigates the effects of various combinations of the planetary boundary layer (PBL) schemes and the microphysics schemes on the numerical forecasting of tropical cyclones (TCs)
In order to make a relative comparison between different combinations of physics schemes, the relative error (Ri) of each TC track predicted by each combination is calculated using the following formula: Ri ði 1⁄4 1. . .; NÞ; ð2Þ

Summary

Introduction

Tropical cyclones (TCs) are one of the most destructing natural hazards (Emanuel 2005; Peng et al 2014) and pose great scientific challenges to meteorologists. The planetary boundary layer (PBL) scheme and the microphysics scheme have been shown critical to the numerical forecasting of TCs, because the boundary layer processes regulate the sources of heat and moisture, and sink of momentum in TCs (Kepert 2012), while the cloud. Many studies focus on the effects of single PBL scheme (e.g., Rao and Prasad 2007; Kanada et al 2012; Kepert 2012) or single microphysics scheme (e.g., Wang 2002, Khain and Lynn 2011; Pattanayak et al 2012). Various combinations of PBL and microphysics schemes may have different influences on TC simulations and forecasts.

The forecasting experiments

The tracks

The steering flows

Atmospheric structures

Conclusions and discussion