摘要
本文计算了冬、夏两季在平原和高原地区分别有低云、高云和当高、低云同时出现时的短波辐射增热率,长波辐射冷却率以及高低云之间的相互影响。结果发现:1)高原上云的短波增热率和长波冷却率要比平原上的大,低云的增热和冷却较平原尤甚。2)高云存在时,地面附近由冷却变为增热。3)高原地区出现双层云时总是使地面附近增热。4)当两层云同时出现时,高云的短波增热率和长波冷却率都有所增大,低云的短波增热率减小,低云的长波冷却率则减小很多。5)低云量的变化对高云的冷却影响较小,而高云量变化对低云的冷却影响甚大。6)云的短波辐射增热受地面反照率的影响不很大,但对太阳高度角的变化甚为敏感。 由以上结果看来,在大气环流和气候模式中必须要很好地考虑高云云量的变化,否则难以得到好的结果。在区域气候模式中不可忽略高原地区和平原地区云的辐射增热和冷却作用的差别。
The atmospheric radiative heating and cooling rates are calculated when one layer high cloud or low cloud appears or two layers of cloud appear simultaneously in plain and plateau areas. The results are: 1) Ths short wave heating rate and long wave cooling rate of cloud over plateau are larger than that over plain, especially for the low clouds; 2) High cloud will heat the surface; 3) Two layer clouds will always heat the surface in plateau; 4) when two layers of cloud appear simultaneously, the heating or cooling rate of the high cloud will be enhanced, while the heating or cooling rate of the low cloud will be diminished; 5) The variation of the low cloud has less influence on the cooling rate of the high cloud, but the variation of the high cloud amount has stronger influence on the cooling rate of the low cloud; 6) The heating rate of the cloud seems unsensitive to the albedo of the ground, but it is sensible to the zenith angle of the sun.In view of this, in general circulation model or in climate models must take care on the variation of high cloud amount. In the regional climate model must take account of the difference of the heating/or cooling rate between the plateau and plain.
出处
《气象学报》
CSCD
北大核心
1991年第4期483-493,共11页
Acta Meteorologica Sinica
基金
国家自然科学基金
