兰州市冬季大气边界层结构特征的观测和数值模拟研究

本文利用甘肃省政府和中国科学院的科技合作项目"兰州市大气污染及对策研究"所获得的系留气球探空资料,并且结合数值模拟方法,对兰州市冬季大气边界层温度场特征进行了对比分析,结果表明:在没有特殊天气过程的典型冬季代表性时段,山谷城市兰州逆温边界层结构无论白天或夜间都存在,而且经常出现多层逆温和白天的脱地逆温情况,只有当冷空气过境时,逆温现象才减弱或消失;与观测结果相比较可以看出,数值模拟结果基本上反应了温度场的主要特征。

OBSERVATION AND SIMULATION STUDY ON STRUCTURE CHARACTERISTICS OF ATMOSPHERIC BOUNDARY LAYER OVER LANZHOU IN WINTER

In this paper,the structure characteristics of atmospheric boundary layer have been studied over Lanzhou in winter by combining numerical simulation method with analysis of the data which was observed by sounding balloon during the collaborative project-"Study on air pollution and countermeasure in Lanzhou" supported by Gansu Government and Chinese Academy of Sciences.The data analysis and simulation results show that:(1) In the representative winter period,which means no special weather,the atmospheric boundary layer over Lanzhou keeps inverse temperature state no matter in the daytime or in night,and the inverse temperature is often at multi-layer(call multi-layer inverse temperature);it is above the ground in daytime(called inverse temperature off ground);Only when cold air is coming,the inversion phenomenon weakens or disappears.(2) The numerical model can simulate the main characteristics of temperature field basically.