夏季午后重庆大气边界层垂直结构分析
网络出版日期: 2025-06-16
基金资助
重庆市自然科学基金项目(CSTB2022NSCQ-MSX0890)
Analysis of the Atmospheric Boundary Layer Vertical Structure in Chongqing on Summer Afternoon
Online published: 2025-06-16
利用雷达探空加密观测资料,对夏季午后重庆山地大气边界层的垂直结构进行分析,给出不同天气条件下大气边界层的一般特征。结果表明,晴天及多云条件下,夏季午后重庆大气边界层表现为典型的对流边界层结构:晴天,对流边界层发展旺盛,地表加热明显,近地面超绝热层较厚、位温递减率较大,边界层高度平均可达1. 5 km,最高达到2. 1 km;多云条件下,对流边界层相对较弱,边界层高度平均只有1. 0 km。阴天,大气边界层表现为典型的上午时段的边界层结构,即在对流边界层与夹卷层之间存在稳定边界层和残余混合层,对流边界层厚度较低,在0. 8 km以下。降雨时,大气边界层位温表现出中性层结特征,即不存在明显的对流边界层结构。在无明显天气过程条件下,边界层的风速整体较低,小于5. 0 m·s-1,甚至出现静风,比湿随高度的变化与位温大致相反;降水条件下,由于受不同天气系统和过程的影响,边界层的风场和湿度特征相对比较复杂和多变。
姜 平, 翟丹华, 朱浩楠, 吴 遥, 张 芬 . 夏季午后重庆大气边界层垂直结构分析[J]. 高原气象, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2025.00009
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 atmospheric boundary layer depicts a typical convective boundary layer structure under clear and cloudy conditions. 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 values less than 5. 0 m·s-1. On cloudy days,the atmospheric boundary layer presents a classic morning boundary layer structure,which means that there is a stable boundary layer and a residual mixed layer between the convective 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 humidity and wind profiles are relatively complex and changeable.
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