一次区域暖雾的特征分析及数值模拟

2004年12月17～19日在我国中东部的大部分地区出现了大雾天气，对这次大雾天气过程进行了综合探测，探测仪器包括粒子测量系统、能见度仪、雾滴谱取样仪以及常规气象观测等。作者分析了部分观测结果并结合区域尺度数值模式，揭示了区域雾的一些基本特征，研究了雾形成和发展机制。结果表明，这是一次典型的辐射雾过程，雾的覆盖范围大，水平分布很不均匀。雾先从地面生成，然后不断向高处扩展，没有出现雾的爆发性增长现象。近地面逆温层的存在、充沛的水汽供应和微风条件有利于雾的形成和维持，太阳短波辐射增温和地面长波辐射降温是雾形成和消散的主要因素。

Characteristic Analysis and Numerical Simulation of a Regional Warm Fog Event

The main purpose is to analysis a regional fog episode occurring in most of middle and eastern China from 17 December to 19 December 2004 based on the observation and the fifth generation Pann State/NCAR Mesoscale Model modeling. The characteristics and evolution process of the regional fog event are investigated. The results show that it is a typical radiation fog event with a large spatial scale and the horizontal distribution is not uniform. The fog appeared at the surface firstly and then expended to the high level. The burst development features of the fog are not found. The temperature inversion and abundant water vapor are the beneficial factors to the fog formation and maintenance as well as breeze condition. The influences of the shortwave radiation warming and longwave radiation cooling are examined.