摘要
为了解沙漠土壤和大气边界层系统中的水分和能量的交换和传输特征，本文发展了一个一维耦合模式，其中包括一个同时考虑土壤中液态水及气态水运动的沙漠土壤模式和一个基于非局地过渡湍流闭合方案的大气边界层模式。用这一耦合模式对沙漠土壤和大气界面的水热交换及沙漠土壤和大气边界层中的水热输送过程进行了模拟，同时与ＨＥＩＦＥ（ＨｅｉｈｅＲｉｖｅｒＢａｓｉｎＦｉｅｌｄＥｘｐｅｒｉｍｅｎｔ）沙漠站的有关资料进行了对比。模拟结果表明约６５％的净辐射能以感热（５０％）和潜热（１５％）的形式提供大气，约３５％的净辐射能以地热流量的形式进入土壤。土壤表层２ｃｍ的范围表现为水热传输的活跃层，水分和温度廓线呈现剧烈的日变化。模拟结果同时表明沙漠土壤中水分传输以气态水为主，如果忽略土壤中的气态水运动。
In order to understand the exchange and transfer processes of water and energy in the desert soil and the atmospheric boundary layer (ABL), A coupled model , in which a desert soil model including water movement of both liquid and vapor phase and an ABL model based on non local transilient turbulence closure scheme are coupled together has been developed. With this model, the evolution of potential temperature and specific humidity, the distribution of net radiation among sensible, latent and soil heat flux, and the water and heat flux profiles both in the soil and ABL have been simulated. The HEIFE observation data are used to calibrate the calculation of the water and heat flux both in the soil and ABL. The sensible and latent heat contribute to warm and moisten the bottom grid box (100m) of the ABL, respectively, by this way, the ABL model and the model are coupled together. The simulated results, also, the observed ones, show that 65 percent of net radiation distributes to the atmosphere, of which 50 percent transforms into sensible heat and 15 percent into latent heat, 35 percent of net radiation distributes to the soil in the form of soil heat flux. In the upper 5cm of the soil, which we call it as an active layer, water and heat transport are more effective than the substrate. When the flux of water vapor in the soil is neglected. The flux profiles of specific humidity in the ABL shows a great change, hence the importance of water vapor movement in the desert soil for the calculation of specific humidity in the ABL.
出处
《气象学报》
CSCD
北大核心
1997年第4期398-407,共10页
Acta Meteorologica Sinica
基金
国家自然基金
"青藏高原地-气系统物理过程观测和理论研究(攀登B)"项目
关键词
沙漠
土壤
大气边界
水热传输
数值模拟
Desert,Soil atmosphere system, Water and heat transport, Numerical simulation.
