太阳辐射日变化对夏季风模拟特征的影响

利用６０°Ｓ－６０°Ｎ范围，有海气耦合但无海流的七层原始方程模式，做了有无太阳辐射日变化的对比试验。结果表明：准定常的平均季风系统的形势受太阳辐射日变化的影响不明显，其主要的影响可能来自海陆和地形分布。但是模式中包含太阳辐射日变化后，大气上下层季风系统强度的模拟得到了改善。太阳辐射日变化在很大程度上影响降水的分布形势，在没有太阳辐射日变化的试验中，大陆内部的降水大大减少，而沿海地区的降水增加。土壤温度和湿度的变化与降水变化对应良好。降水增加和减少的地区呈波状分布。至于对季风发展的影响，结果表明在季风发展的初期，太阳辐射日变化可加快其发展。因此，太阳辐射日变化的引入，可使平衡态较早达到

EFFECTS OF DIURNAL VARIATION OF SOLAR RADI ATION ON THE SIMULATED PROPERTIES OF THE SUMMER MONSOON

In this paper, comparative experiments with and without diurnal variation of the solar radiation are made by use of a 5 layer primitive equation air-sea coupled model system without oceanic currents in a zonal domain between 60°S and 60°N. The results show that the diurnal variation of the solar radiation does not have very large influence on the mean monsoon system in the quasi-equilibrium state, the main influences may come from the land-sea and the topography distributions. However, its inclusion into the model does improve the simulations of the monsoon systems at the upper and the lower levels. The diurnal variation of the solar radiation influences the simulated precipitation pattern quite a lot. In the experiment without the diurnal variation of the solar radiation, the precipitation amount over the land areas is greatly reduced while it is increased over the areas along the coasts. The changes of the soil temperature and moisture fields are well corresponding to the changes of precipitation. The areas with increased precipitation and the areas with decreased precipitation are distributed in a wavelike form. As the monsoon development is concerned it is shown that the diurnal variation of the solar radiation can speed up the development at the early stage. Therefore, the inclusion of the diurnal variation of the solar radiation can make the summer monsoon reach the quasi-equilibrium state earlier.