山西、京津地区低能见度预报指标及其产生背景分析

Low Visibility Forecast Index and its Original Background Analysis over Shan xi,Beijing and Tianjin Area

本文根据1995年至2002年天气史料记载,得出每年11月中旬至12月中旬是山西、京津地区由于雾导致低能见度多发时间。从产生低能见度的各种因子变化规律入手,讨论了它们形成时的日变化规律,气压场、湿度及流场特征,为初冬山西、京津地区低能见度天气的变化规律及其预报工作提供了一些有参考价值的依据。

According to the weather historical data from 1995 to 2002, lo w visibility caused by fog usually appear in Shanxi, Beijing and Tianjin area from mid-November to mid-December for each year.This article analyzed the change rule of each kind of factor caused low visibility and discussed the daily varia tion rule when formed,the pressure field,the humidity and the circulation field characteristic,provided some reference basis for its change rule and forecast in earlier winter in Shanxi, Beijing and Tianjin area.