连续强沙尘天气的发展和时空演变机制的数值模拟

2002年4月6-8日由蒙古气旋和地面冷锋引发了一次连续沙尘暴天气,特别是内蒙古中东部、华北和东北大部分地区沙尘持续影响时间较长,强度大。利用与非静力平衡中尺度气象模式完全耦合的区域沙尘数值模式,模拟研究这次强沙尘天气过程中沙尘浓度的空间分布结构和时间演变趋势。模拟结果与地面天气观测、定点沙尘颗粒物浓度观测资料进行对比和检验。结果表明:沙尘数值模式较逼真地刻画出这次连续强沙尘天气的形成、发展、移动、减弱的全过程；客观地揭示了强沙尘天气过程的垂直分布结构和沙尘浓度的时空演变机制；模拟的强沙尘以及输送至下游的浮尘天气范围、强度和出现时间与实况基本一致,特别是对我国华北和东北沙尘的模拟相当成功。高时空分辨率的数值模式对研究沙尘的发生、发展机制和预报预警有重要意义。

Simulation on Development and Evolution Mechanism of a Continuous Strong Dust Weather Event

A continuous strong dust weather occurred from April 6 to 8 in 2002 in most part of China,especially in middle and east Inner Mongolia,north and north-east China.This long time dust weather event was induced by Mongolian cyclone and surface cold front.The spatial and temporal distribution and development of dust concentration and structure were simulated by a coupled dust model with non-hydrostatic mesoscale model.The modeling results were validated with surface weather reports and observed dust particle concentration as well as satellite remote sensing image for dust.The results showed that the coupled dust model could depict the full processes of continuous dust weather's formation,development,movement and weakening.The model reasonably revealed the vertical structure and the spatial-temporal evolution of dust concentration during strong sand-dust weather.The dust development and its strength and range from the model were in good agreement with the real observations.High resolution dust model could be a good method for mechanism study of dust weather's occurrence,development and transport and for dust forecasting and warning in operation.