非均匀下垫面边界层的观测和数值模拟研究(I):冷岛效应和逆湿现象的完整物理图像

利用HEIFE、DHEX和GAME/Tibet 3个观测试验和部分常规气象站观测资料,分析了下垫面非均匀条件下产生的冷岛效应和逆湿现象的完整物理图像以及它们对地表能量和五水转化的影响.分析结果表明,下垫面非均匀特征对五水转化有着明显的影响;冷岛效应和逆湿现象是下垫面非均匀性的必然结果,它们在自然界普遍存在;现有陆面过程模式很难刻画冷岛效应和逆湿现象,通常现有陆面过程模式很难将冷岛效应中的热量平流转化成蒸发潜热,同时陆面过程模式也混淆了逆湿现象和发生在下垫面上的大气水的冷却凝结.这些评述将有助于今后非均匀陆面过程的进一步研究.

Observation and Numerical Simulation of Heterogenous Underlying Surface Boundary Layer (I):The Whole Physical Picture of Cold Island Effect and Inverse Humidity

Using the observational data of HEIFE, DHEX and GAME/Tibet experiments and at some routine meteorological stations, the whole physical picture of the clod island effect and inverse humidity under heterogeneous land-surface condition over west China and their effect on surface energy and tramsformation among atmospheric water, surface water, soil water, under ground water and plant water were analyzed. The analyzed results show that the characteristics of heterogenous underlying surface have clearly effected on water transformations. The clod island effect and inverse humidity are certain result of underlying surface heterogencity, and they exist common in nature. The existed land-surface process models are hard to depict the cold island effect and inverse humidity phenomenona. They can not transfer heat advection in cold island effect into latent heat of evaporation. Meanwhile, it can not distinguish the inverse humidity phenomenon and cooling condensation of atmospheric water in the underlying surface. This review is useful for future study of heterogeneous land-surface processes.