长治市大雾气候特征及预报研究

Characteristics and prediction of heavy fog weather in Changzhi City

通过对长治市1971-2004年水平能见度<1km的大雾的地理分布特征,及其年际、月际和日变化的统计研究,给出了该市大雾天气的气候背景。根据大雾形成的物理机制,对风场、湿度场、温度场、冷却条件分别进行了分析,建立了大雾综合预测模型。通过98个大雾个例的分析,归类了形成大雾的主要500hPa高空天气形势(纬向环流型、弱西北气流型、槽后西北气流型、弱高内部型)和地面主要气压场(弱高压场、均压场、鞍型场),供大雾灾害预警预报参考。

The background of fog climate which horizontal visibility less than lkm in Changzhi City, was explored by researching the geographical distribution of the fog and its yearly, monthly and daily changes from 1971 to 2004. According to the physical mechanism of formation of fog, authors analyzed wind field, humidity field, temperature field and cooling condition, then integrated fog prediction model. With the analysis of 98 examples of fog, we classified the dense fog-forming main 500 hPa high-altitude weather situation （ zonal circulation pattern, weak northwest flow pattern, after the trough northwest flow pattern, weak internal high pattern） and the main ground pressure field （weak high pressure field, both pressure field, saddle field）. The results can give a reference to early warning and forecast of the heavy fog weather.