绿洲效应的模拟及内外因子的敏感性实验  

Numerical Simulation of Oasis Effect and Its Sensitivity Test of Inside and Outside Factors

作　　者：刘树华[1] 胡予[1] 胡非[2] 梁福明[1] 王建华[1] 刘和平[1] 

机构地区：[1]北京大学物理学院大气科学系暴雨和旱涝灾害教育部重点实验室大气边界层和湍流研究组,北京100871 [2]中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室,北京100029

出　　处：《大气科学》2005年第6期997-1009,共13页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金资助项目40275004;中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室资助;北京大学物理学院大学科学系暴雨和旱涝灾害教育部重点实验室共同资助

摘　　要：利用一个已发展的陆面物理过程参数化方案与大气边界层数值模式耦合,模拟了半干旱区绿洲戈壁非均匀下垫面的陆面物理过程及其与大气边界层的相互作用,成功地描绘了绿洲戈壁局地气候效应,并进行了绿洲戈壁局地气候效应对于降水、绿洲水平尺度和植被结构等若干内外因子的敏感性实验。结果表明:绿洲的最小临界尺度为5~10 km之间,最大临界尺度为55~65 km之间,而最利于绿洲维持的尺度范围为20 km左右,这一结论与我国西部地区现存的绿洲尺度统计结果十分一致;绿洲植被覆盖率为0.6左右时,最利于绿洲发展。另外对植被空间分布方式和绿洲植被组成比例上也进行了数值实验,并对影响绿洲生存和持续发展的内、外因子气候效应的影响力量级进行了分级。这些结果对于深入了解绿洲气候的形成和维持机理具有重要的意义。A developed parameterized scheme of land surface physical process and transfer models are used for simulating the oasis-gobi interaction process and the oasis-gobi regional climate effect in the semi-arid region. The scheme is composed of two main parts： land surface processes and boundary layer processes, and the corresponding models include two versions： two-dimensional and three-dimensional. The sensitivities of the oasis-gobi regional climate effect to inside and outside factors such as precipitation, oasis horizontal spatial scale, vegetation structure etc. are studied. After these studies, many significant results are obtained. Result shows that large-scale wind speed of the background field is an important factor to affect mesoscale atmospheric circulation motion of the oasis-gobi region. Precipitation and irrigation play important roles in maintaining evolution of oasis, and precipitation has much greater influence on the oasis-gobi regional climate effect in the semi-arid region than irrigation. Horizontal spatial scale of oasis is a very important inside factor to influence oasis effect, and the smallest critical scale range of oasis is 5 - 10 kin, the largest critical scale range of oasis is 55 - 65 kin. Oasis will evolve very well when the horizontal spatial scale is about 20 kin. These results reach unanimity with horizontal scales of oasis in the northwest region of China now. Moisture of soil also has some influence on oasis effect, especially on “cold island effect”, and perhaps every oasis also has the critical moisture content of soil to affect the existent stability for itself. It has been proved that roughness length of land surface is a minor factor to the oasis-gobi regional climate effect in the semi-arid region through the special numerical simulation tests. At last, a series of numerical simulation experiments are carried out to research the functions of vegetation structure to the oasi^gobi regional climate effect in the semi-arid region. In this paper, vegetation structure is co

关 键 词：陆面物理过程参数化方案 绿洲效应 内外因子 敏感性实验 

分 类 号：P463[天文地球—大气科学及气象学]