不同初始场资料对台风“桑美”数值模拟的影响

Influence of Different Initial Fields on Numerical Simulation of Typhoon Saomai

以2006年超强台风'桑美'为个例,分别以GFS(全球预报系统)再分析资料和JMA(日本气象厅)区域客观再分析资料为初始场,利用中尺度模式WRF(Weather Research and Forecasting Model)对台风'桑美'进行高分辨率数值模拟,分析不同初始场资料对台风内部结构和移动路径的影响。结果表明:对于500hPa高度场和850hPa水汽、风场等预报,GFS再分析资料和JMA区域客观再分析资料均能较好地把握台风整体的流场形势。从700hPa风场、近地面风速、降水、雷达反射率、最小海平面气压和最大风速等模拟效果来看,JMA区域客观再分析资料均优于GFS再分析资料。对于台风路径的预报,前15h内JMA区域客观再分析资料较GFS再分析资料要好,而15h之后,以这两种资料作为初始场的台风预报路径与实况均有较大偏差。

The GFS(Global Forecasting System)reanalysis and JMA(Japan Meteorological Agency)reanalysis data are applied as the initial conditions for the simulation of the super Typhoon Saomai in 2006 respectively in this study.Based on the WRF(Weather Research and Forecasting)Model,numerical simulations were conducted to analyze the influence of different initial conditions on the internal structure and movement path for Saomai.The results show:For the forecasts of the 500 hPa geopotential field and the composite field(such as water vapor and temperature)of 850 hPa,GFS and JMA data are able to well grasp the overall flow field situation.JMA data are superior to GFS data for simulating fields such as the wind speed(700 hPa and near-surface),precipitation,radar reflectivity,minimum sea level pressure,and maximum wind speed.For the typhoon track forecast,JMA data in the first 15 hours are better than GFS data,but after 15 hours,both forecasting fields have a significant deviation.