2017年7月一次微下击暴流背景的多尺度特征

利用中尺度数值模式WRFV3.6模拟了2017年7月12日宁波机场附近的一次微下击暴流天气过程，结合浙江省自动站资料、机场自动观测数据、多普勒天气雷达资料等分析微下击暴流成因，结果表明：此次微下击暴流是由海风锋触发的强雷雨引起的，机场自动观测数据显示的风、温、压等气象要素的变化均呈现出明显的微下击暴流特征；数值模式较好地模拟出微下击暴流的水平风场结构；拖曳作用、下沉过程中冰雹融化、液态水和雨水持续蒸发降温作用是形成此次下击暴流的重要原因；低层位温扰动加强了垂直运动，中低层位涡异常增大区与雷暴强降水区域有较好对应关系。

A Multi Scale Study on Background of a Microburst in July 2017

A microburst process on 12 July 2017 near Ningbo Airport is simulated by the mesoscale numerical model WRFV3.6 and its formation mechanism is analyzed using the data of automatic meteorological stations over Zhejiang Province, automatic observation data collected at the airport and Doppler radar data. The study shows that the microburst was triggered by a strong thunderstorm which was caused by a sea breeze front. The changes of wind, temperature, pressure of the AWOS observation data show the obvious characteristics of microburst. The horizontal wind field structure of the microburst is simulated well in the simulation test. Dragging effect, hail melting during subsidence, continuous evaporation, and cooling of liquid water and rainwater are important reasons for the formation of the microburst. Low level temperature disturbance enhanced vertical motion, and the abnormal increase area of the middle and low level vortex has a good correspondence with the thunderstorm heavy rainfall area.