摘要
利用中尺度数值模式WRFv2.2较好的模拟结果,并结合NCEP再分析资料、地面自动站降水资料以及实况雷达回波资料对台风"海棠"造成的浙闽地区特大暴雨进行分析。研究发现,这次暴雨属于台风中心北侧附近的螺旋云带降水,主要是由边界层强中尺度辐合带直接影响造成的,降水伴随着辐合带发展;边界层顶的强东风急流和对流层低层强偏南气流在浙闽地区的交汇是强辐合带的成因;台风向西北方向移动相伴东风急流和强辐合带的北移,这是本次暴雨出现稳步北抬的原因。台风的三支不同气流在浙江南部和福建北部地区交汇上升,起到了水汽通道和能量输送以及建立不稳定区的作用,提供了暴雨的增幅与维持,而气流的汇合主要发生在边界层内,这也是中尺度辐合带高度受限于边界层的原因。浙闽地区复杂的中尺度地形对本场暴雨的发生有重要作用,为暴雨的增幅做出了重要贡献,但是,对边界层不同气流造成的中尺度辐合带而言,地形的作用较小,仅可阻挡降水向西延伸。
Successful numerical simulation output from WRFV2. 2 combined with NCEP reanalysis data, observed precipitation data from automatic stations and Doppler radar reflectivity are used to analyze the heavy rainfall caused by typhoon Haitang in Zhejiang and Fujian provinces. The results show that the heavy rainfall is from the spiral clouds band close to the north of the typhoon center, and caused directly by the strong mesoscale convergence belt in the boundary layer. The rain belt develops and moves northward corresponding to the convergence belt. Three ty-phoon currents from different directions converge and ascend near the boundary of Zhejiang and Fujian provinces, transporting moisture and energy for the strengthening and maintenance of heavy rainfall. The confluence of these currents mainly happens in the boundary layer, which is the reason why the mesoscale convergence belt is confined in the boundary layer. The complicated mesoscale orography in Zhejiang and Fujian provinces plays an important role in the storm. The three different currents lift upward along the mountains ranging from north to south and trigger precipitation, which contributes to the heavy rainfall. However, the terrain plays no effect on the mesoscale convergence belt but prevents the precipitation from extending westward.
出处
《大气科学》
CSCD
北大核心
2009年第3期489-500,共12页
Chinese Journal of Atmospheric Sciences
基金
浙江省重大科技攻关专项和社会发展重点项目2006C13025
浙江省气象科技开放项目KF006007
国家自然科学基金资助项目40805018
关键词
台风暴雨
数值模拟
WRF模式
中尺度辐合带
地形
numerical simulation of typhoon heavy rainfall, WRF model, mesoscale convergence belt, orography
