夏季两种类型高温特征对比和舒适度评价

对上海金山1981—2010年湿热型高温和干热型高温的基本特征以及背景场特征进行分析,并结合人体舒适度讨论两类高温对人们生活工作影响的特点和规律。结果表明:1干热型高温由强大副高控制,地面处于高压顶后或顶前的晴空区;湿热型高温由较强副高控制,地面多处于低压底部,易受水汽影响。2干热年较湿热年,西太平洋副高偏西、偏强,南亚高压偏东、偏北、偏强,夏季风较强,尤其是南风分量偏强显著,下沉运动偏强。3湿热年纬圈方向900hPa以下为上升运动,利于对流活动的发生。4两类高温皆有全天持续热不舒适特点,白天湿度作用明显,湿热型高温持续极热特征突出,严重不舒适感强烈;夜间主要受温度影响,干热型高温造成不舒适感较大。

Characteristic and Comfortability Evaluation of Two Types of Summer High Temperature Weather

The basic characteristics and different background characteristics of wet-heat high temperature and dry-heat high temperature weather in Jinshan from 1981 to 2010 are studied. The impacts of high temperature on the people＇s life and work are studied with the human-body comfort index. The results indicate： （1） The dry-heat high temperature weather is controlled by strong subtropical high at upper levels, and the surface is usually in the clear area before or after a high pressure system; the wet-heat high temperature weather is controlled by the less strong subtropical high, and the surface is mostly at the bottom of a low pressure, leading to invasion of moisture. （2） During the years of dry-heat high temperature, the West Pacific high is found to be more westward and strengthened, and the South Asia high lies more easterly and northerly, with stronger summer monsoon and stronger descending motion. （3） During the years of wet-heat high temperature, ascending motion exists below 900 hPa in latitudinal direction, which is favorable to the development of convective activities. Two types of high temperature show the characteristic of persistent discomfort all day long. （4） During the daytime, the wet-heat high temperature has longer duration of extreme high temperature and greater body discomfortibility, while during the nighttime the dry-heat high temperature weather has greater body discomfort.