对流温度在北京夏季局地热力对流云分析中的应用

Application of Convective Temperature in Analysis of Local Thermodynamic Convective Clouds in Beijing Summer

利用北京近郊地区南苑机场1990-2000年6-8月观测资料,分析了北京夏季对流云出现日数、出现时间、云底高、生命史等基本特征;利用北京站1995-2000年6-8月常规探空资料,分析了北京夏季对流温度和对流凝结高度的特征,尝试用对流温度预报对流云的出现,用对流凝结高度预报对流云的云高。结果表明:对流温度在局地热力对流云的预报中具有一定的指示意义,对流凝结高度能在一定程度上反映出对流云的云高。有对流云时,对流温度与实测温度之差在4℃以内的,占对流云总数的80%。在对流温度与实测温度之差≤4℃的有对流云日内,对流凝结高度与实测对流云云高之差90%以上都是在1200m以内,500m以内的也达到了53%。

By using 1990—2000 during June and August observation in Nanyuan airport in regional of Beijing,the characteristics such as convective cloud days,arisen time,the cloud base height,life cycle were analyzed.By using routine sounding data during June and August from 1995 to 2000 in Beijing,the characteristics of convective temperature and convective condensation level were also studied,try to use convective temperature to forecast convective clouds,and use convective condensation level to forecast convective cloud height.The results show that there is some indicative significance when using convective temperature to forecast convective cloud.Convective condensation level can reflect the cloud height of convective cloud to a certain extent.Convective cloud days when the difference between convective temperature and observed temperature are less then 4 ℃ take up 80 percent.When the difference between convective temperature and observed temperature are less then 4 ℃,the difference between convective condensation level and the cloud height of convective cloud less than 1200 meter take up more than 90 percent,even then less than 500 meter also take up 53 percent.