Page 233 - 《高原气象》2025年第5期

5 期 姜 平等：夏季午后重庆大气边界层垂直结构分析 1351

Analysis of the Atmospheric Boundary Layer Vertical Structure

in Chongqing on Summer Afternoon

1， 4
1， 2
JIANG Ping ， ZHAI Danhua ， ZHU Haonan ， WU Yao ， ZHANG Fen 1， 4
3
1， 4
（1. Chongqing Climate Center， Chongqing 401147， China；
2. Chongqing Meitian Technology Co. ， Ltd， Chongqing 401121， China；
3. CMA Economic Transformation of Climate Resources Key Laboratory， Chongqing 401147， China；
4. Chongqing Meteorological Observatory， Chongqing 401147， China）

Abstract： In this paper， the vertical structure of the atmospheric boundary layer in Chongqing on summer after‐
noon is analyzed using the sounding data with intensive observation. The general features of the vertical structure
of the atmospheric boundary layer under different weather conditions are also given. The results show that the at‐
mospheric boundary layer depicts a typical convective boundary layer structure under clear and cloudy condi‐
tions. On clear days， the development of convective boundary layer is very vigorous， the surface transpiration/
evaporation is strong， and there is obvious upward water vapor transport. The near-surface superinsulation layer
is thick， and the potential temperature lapse rate is large. The height of the boundary layer can reach 1. 5 km on
average and up to 2. 1 km， while the height under cloudy conditions is relatively low， with an average height of
1. 0 km. Under sunny and cloudy conditions， the wind speed in the boundary layer is generally low with the val‐
ues less than 5. 0 m·s . On cloudy days， the atmospheric boundary layer presents a classic morning boundary
-1
layer structure， which means that there is a stable boundary layer and a residual mixed layer between the convec‐
tive boundary layer and the entrainment layer. Under this condition， the thickness of the convective boundary lay‐
er is relatively low， with a magnitude of less than 0. 8 km. The specific humidity profile presents a feature oppo‐
site to the potential temperature profile， and the boundary layer wind speed is relatively low. When it rains， the
potential temperature depicts a neutral stratification feature and shows no obvious convective boundary layer
structure. Due to the influence of different weather systems and processes， the characteristics of specific humidi‐
ty and wind profiles are relatively complex and changeable.
Key words： summer afternoon； atmospheric boundary layer； vertical structure； synoptic conditions