一次超级单体风暴多普勒天气雷达资料的低层风场反演研究

THE LOWER LEVEL WIND RETRIEVAL APPLIED TO A SUPER CELL STORM USING DOPPLER RADAR

本文使用二维变分风场反演方法对浙江台州2003年4月12日一次超级单体风暴的多普勒天气雷达探测资料进行低层风场反演研究。二维变分方法以均匀风场反演结果作为初猜场,在目标泛函中加入散度和涡度约束作为正则项来降低不适定性的影响。反演得到的低层水平风场比较好的符合超级单体风暴的组织化的气流结构和强的风切变,通过对散度场垂直积分获得垂直速度,上升气流主要集中在强回波区域,下沉气流一个位于风暴前进的左侧的弱回波区,一个位于钩状回波的内侧。

2Dvar method was applied to retrieving lower level wind fields of a super cell storm case observed by Doppler radar located at Taizhou city Zhejiang province on 12 April, 2003. The wind fields retrieved by Uniform Wind method was used as the initial fields. The convergence and vorticity are used as regularization term to decline the effect of ill-posed problem. The retrieved lower level wind fields indicate consistency with the systematical flow structure, show strong horizontal and vertical shear. The vertical integral was conducted to convergence to gain the vertical speed. The upper flow is limited to the strong reflectivity area; one down flow is found in the weak reflectivity area on the left of the direction of the storm moving,another is found in the inner edge of the hooked reflectivity.