Abstract:

Based on the German RPG ground-based microwave radiometer observations, firstly the sounding and microwave radiometer data were compared, and the deviation and the root mean square error of two kinds of data were calculated in order to test the reliability of the ground-based microwave radiometer data, then combined the conventional meteorological observations, the atmospheric boundary layer inversion feature in 2015 in Ji’nan was analyzed. The results are as follows:（1）The precipitation process had certain influence on the microwave radiometer observations, and there was a good consistency between the sounding and microwave radiometer data under no rainfall condition. (2)The monthly average frequency of ground inversion layer occurring in Ji’nan was 84.9 %, and it was 100% in February, September, October and December. Due to unstable atmosphere stratification and stronger convection in summer, the ground inversion was weaker and the frequency was only 46.6%. (3)The frequency of overhang inversion was smaller in 2015 in Ji’nan, and it was maximum in April with the value of 30% only. (4)The ground inversion layer thickness distributed unevenly with an obvious peak value of 900 meters in 2015. It was easily observed that ground inversion temperature difference climbed higher and its intensity reached a maximum value of level 6 in spring, and it dropped down in summer with a minimum intensity value of level 1, in the rest two seasons the ground inversion intensity reached level 3. (5)The overhang inversion layer had a top height of 2 000 meters in winter when its temperature difference reached 8.0 ℃, and a relatively small value of 0.5 ℃ in summer when its intensity was as low as level 2.

Key words:  boundary layer inversion, the ground-based microwave radiometer, inversion thickness , inversion intensity

摘要：

利用德国RPG地基微波辐射计观测数据，首先对比分析探空和微波辐射计观测数据，计算2种数据的偏差和均方根误差，检验地基微波辐射计观测数据的可靠性，然后结合常规气象观测资料分析2015年济南地区大气边界层逆温特征。结果表明：（1）降水天气过程对微波辐射计观测数据有一定影响，无降水天气过程时2种数据有很好的一致性；（2）2015年济南贴地逆温月平均出现频率为84.9%，其中2、9、10、12月出现频率为100%。夏季由于大气层结不稳定、对流旺盛，贴地逆温较弱，出现频率仅为46.6%；（3）2015年济南悬垂逆温出现频率较小，其中4月出现频率最大（仅为30%）；（4）贴地逆温层厚度全年分布不均匀，最大为900 m，伴随夏季到来，逆温温差变小，夏季结束，温差变大，最大温差为4.6 ℃；逆温强度春季最大，强度可达6级，夏季最小，仅为1级，其他季节为3级；（5）悬垂逆温层冬季最高，顶高可达2 000 m，温差有较大差异，冬季最大温差为8.0 ℃，夏季温差较小，最小温差为0.5 ℃，逆温强度不大，最大强度为2级。

关键词: 边界层逆温, 微波辐射计, 逆温厚度, 逆温强度