张家口市一次持续高温天气成因分析

利用天气图资料、NCEP 1°×1°再分析资料和地面观测资料以及热流量方程,从天气学角度分析了2010年7月下旬张家口地区高温天气产生的主要原因。结果指出:高温是在大陆高压持续稳定控制的天气形势背景下产生的,然而在这种情况下,温度平流因子对高温所起的作用不是最主要的,非绝热条件才是高温日出现的关键;地面温度较高且持续时间较长,也为7月29日最高气温创下历史新极值做出了一定贡献;对高温日最高气温与当日14:00 850hPa温度做了对比分析,认为二者相差9℃可以作为高温日最高气温预报的参考。

Causal Analysis of Sustained High Temperature Weather in Zhangjiakou

The main causes of the high temperature weather occurred in Zhangjiakou in late July 2010 are analyzed by using the data from weather maps, NCEP reanalysis data and ground observations, based on the heat flow equation. The results show： （1） High temperature appeared in the background of the steady control of the mainland high. （2） Under the control of the mainland high, the non-adiabatic condition was the key factor leading to high temperature, while the thermal advection had less effect. （3） Higher surface temperature and the longer duration may also make some contributions to the new record-breaking high temperature on July 29 2010. （4） The maximum temperatures were compared with the corresponding 850 hPa temperatures at 14：00 of the hot days, and a difference of 9 ℃ between them can be used as a suitable reference in maximum temperature forecasting.