冬季北京城市近地层的气象特征

运用2001年1～3月北京大气边界层和大气化学综合试验期间,中国科学院大气物理研究所铁塔上所获得的8～320 m 15层风、温度和湿度梯度资料,对冬季北京城市边界层特征进行了诊断分析.结果表明,在冬季北京城市边界层中,平均而言地表粗糙度为1.34、零平均位移约为20 m;温度基本上随高度呈线性变化;风速随高度的变化并不总遵循对数关系,尤其是在午前和夜间,风速与高度之间对数关系的不显著率可达30%～40%.不能简单套用在Monin-Obuhov相似理论中由Businger-Dve风廓线层结订正获得的近地面层动量、热量和水汽湍流输送计算公式.

METEOROLOGICAL CHARACTERISTICS OF THE GROUND LAYER IN BEIJING IN WINTER

The urban ABL characteristics of Beijing in winter are diagnosed by means of the wind and temperature data observed at the heights of 8 to 15 m from the observation tower located in the Institute of Atmospheric Physics, Chinese Academy of Sciences, during the comprehensive experiment on the Beijing ABL and atmospheric chemistry. Results indicate: the average surface roughness is about 1.34 m and the zero plane displacement is about 20 m; temperature is basically linear with height; wind speed is not always follow the logarithmic relationship. Especially before noon and at night with the non significance being 30%-40%, the formulae for calculating the near surface momentum, heat and water vapor through the Businger Dye wind profile and stratification correction in the Monin Obuhov theory cannot be used indiscriminately.