河南省一次大雾的数值模拟及生消机制分析

Numerical Simulation and Development Mechanism Analysis of Heavy Fog Process in Henan Province

应用非静力平衡中尺度模式MM5及NCEP资料和高空地面资料，模拟分析了2006年1月28日发生在河南省的一次大雾天气过程，结果发现：这次雾体最强的时段在日出后1～2h内，相对湿度下降的拐点滞后于气温回升的拐点2h左右；先出现贴地逆温再出现大雾，逆温最强的时段也是雾体最强的时段，逆温层顶始终覆盖在雾体上方；近地面的微风和风向的转变，有利于雾体的形成和向上发展，风向转变的时间也是雾体形成的时间；增温、减湿和逆温层的破坏是大雾消散的主要原因。

This paper presents simulated results of heavy fog process that occurred on January 28, 2007 in Henan province using the non-static equilibrium mesoscale model MM5, the NCEP data, and the upper air and surface data. The results show the period of strongest fog time was behind sunrise 1 - 2 h, and the flex point of relative humidity decline was behind temperature uptrend about 2 h. It was earlier that ground-hugging inversion appeared than heavy fog, and the most inversion was consistent with the strongest fog, and the inversion layer was above the fog; the breeze and the wind shift of surface layer was favorable the heavy fog appearing and growing upwards ; the major reason of heavy fog vanishing was elevated temperature, dehumidification and destroyed inversion layer.