摘 要 在最近幾年來，陸地表面作用過程和其模式化的方法，在全球及區域性中尺度氣候數值模擬模式上，漸漸被廣泛的認為是重要且必須的。然而在MM5耦合由奧勒岡州立大學發展出的陸地表面水文數值模擬模式(Oregon State University land surface model之後簡稱OSU-LSM)並未考慮地勢傾斜對水文過程的影響。在眞實情況下，地表上水量分佈應會受到地勢傾斜影響，由相對地勢較高處向相對地勢較低處流動。因此我們將會加入地勢斜率效應，修正OSU-LSM模式對表面水量分佈狀態的預報。 由三種不同物理情境模式下相互比較(MM5模式、MM5耦合OSU-LSM水文模式、MM5耦合OSU-LSM水文地勢斜率效應修正模式)，發現到OSU-LSM水文模式可以彌補MM5模式在陸地表面水文過程中，所忽略地表和地底水含量對能量收支的影響。 接著由OSU-LSM水文模式加入地勢效應修正跟OSU-LSM水文模式相互比較，可以發現OSU-LSM水文地勢效應修正模式，表面水量會因為地勢斜率效應而向外流動，使模式模擬地表水量分佈更為合理化，跟著地表表面能量通量也發生變化，進而改變OSU-LSM模式對水文場的預報。 由模擬結果的比較中，可以明顯的發現到，地勢斜率效應對地表水量的分佈狀態造成改變後，對於OSU-LSM模式提供給MM5，作為地面初始資料場的地表潛熱、可感熱釋放通量場，有相當重要的影響，進而對MM5耦合OSU-LSM模式對氣象場的模擬預報，產生修正效果。 ABSTRACT It has been widely accepted that land surface processes and their modeling play an important role, not only in large-scale atmospheric models, but also in regional and mesoscale atmospheric models. In the Penn State-NCAR fifth-generation Mesoscale Model (MM5) used has its origin at the Oregon State University land surface model (LSM). But in the MM5-LSM, hydrological processes that the horizontal distribution of surface water should be depended on the topographic slopes were not included. Topographic slopes will cases outflows from higher topography to lower. Then the horizontal distribution of surface water and the soil moisture should be changed. So, we wish to address this aspect of the problems. We will compare with between the third kinds of different physical state’s simulation (the MM5’s simulations, the MM5-LSM’s simulations and the MM5 - LSM’s simulations with topographic effect), we find that the LSM can improve the simulation of the surface energy balance with add soil moisture to the MM5.Then the horizontal distribution of surface water and the soil moisture will be more real in the MM5-LSM’s simulations with topographic effects. Therefore the surface energy fluxes will be different, including both the sensible and latent heat fluxes. Thus it is expected the modifications will not only affected the weather simulations but also the climate simulations.
