登陆台风中的波动对强降水落区与强度的影响研究

Typhoon, especially the landfalling typhoon has great influence on the human beings and national economy. Strong rainstorm caused by landfalling typhoon is the main factor which causes serious meteorology disasters. So the deep understanding on the mechanism of strong rainstorm which is related to landfalling typhoon not only is crucial in the prevention of disasters caused by typhoon, but also has important scientific meanings.. The research work in this project would use the assimilation results of conventional and unconventional data such as high-resolution satellite and radar data, with sounding and surface observation data, to carry out numerical simulation on the heavy rainfall process of landfalling typhoon. We also study the factors which may have influence on the strength and area of heavy rainfall, including the energy dispersion of the vortex Rossby wave-packet and the concentration of wave-action density of gravity wave. From the perspective of wave action in landing typhoon, we discussed the mechanism of strong rainfall in landing typhoon, in hope of having deeper understanding of the heavy rainfall caused by landing typhoon and improving the typhoon forecasting. Our research may also provide theoretical basis on the forecasting of heavy rainfall caused by typhoon and scientific ideas on forecasting.

台风，特别是登陆台风对人类的生存环境及国民经济影响巨大，而强降水又是登陆台风最主要的气象致灾因子之一，因此深入理解登陆台风强降水过程的形成机理，不仅有利于国家防台减灾，而且具有十分重要的科学意义。. 本研究的工作拟利用高分辨率的卫星、雷达以及高空、地面观测等常规和非常规资料进行同化，对登陆台风强降水过程进行数值模拟，利用高分辨率的模拟结果研究登陆台风强降水过程波动的特点，研究涡旋Rossby波波包的能量频散对强降水落区与强度的影响。研究重力波的波作用密度的集中对强降水落区与强度的影响。从登陆台风中波活动的角度来探讨强降水相成的机理，以期加深我们对登陆台风强降水过程的理解和认识，并进而提高其预报水平，为台风强降水的预报奠定一定理论基础，并为预报提供科学思路。

本项目的研究工作是利用高分辨率的卫星、雷达以及高空、地面观测等常规和非常规资料进行同化，对登陆台风强降水过程进行数值模拟，利用高分辨率的模拟结果研究登陆台风强降水过程波动的特点，加深我们对登陆台风强降水过程的理解和认识，为预报提供科学思路。 我们利用中尺度非静力数值模式ＷＲＦ对２００９年８号台风莫拉克进行了高分辨率数值模拟，模拟的台风路径与观测路径较为一致，同时“莫拉克”台风的强度演变过程以及主要的雷达回波特征也有较好再现。利用物理量广义波作用密度因子对“莫拉克”引发的暴雨过程进行诊断分析，结果表明，广义波作用密度能够综合表征莫拉克台风降水系统动力场和热力场扰动的典型垂直结构，对强降水落区有较好的指示作用。 另一方面，我们还利用WRF模式对2015年22号台风“彩虹”进行高分辨率的数值模拟,成功地模拟出台风“彩虹”的移动路径，强度和降水分布，尤其是在台风登陆前后，模拟结果与实况比较相近。研究结果表明，涡旋Rossby波的1波、2波的动力配置影响了对流系统的发展，并对降水强度和分布有着一定的诊断作用。