澳大利亚植被覆盖对亚澳季风影响的数值模拟(I):对澳洲气候及冬季风的影响  

Numerical Simulation about Impact of Vegetation Cover over Australian Land on Asian-Australian Monsoon (I):Impacts on Regional Climate and Winter Monsoon in Australia

作　　者：鲍艳[1] 吕世华[1] 刘海辉[2] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,甘肃兰州730000 [2]解放军理工大学气象学院,江苏南京211101

出　　处：《高原气象》2006年第5期763-771,共9页Plateau Meteorology

基　　金：中国科学院知识创新重要方向性项目(KZCX3-SW-221);中国气象局兰州干旱气象研究所干旱气象科学研究基金项目(IAM200513;200608)共同资助

摘　　要：通过澳大利亚植被绿化和沙漠化的数值试验,对植被覆盖变化引起的地方性气候变化及对半球尺度环流的影响进行了探讨.结果表明,澳洲大陆植被覆盖变化可显著影响地方性温湿和降水,大陆中西部绿化可使大陆东部显著降温,局地水汽增加对温度变化影响显著.绿化引起的中东部降水增加与地表粗糙度增加引发的水汽辐合增强,垂直上升运动增强引发的对流旺盛有关系.局地温湿和环流的变化通过大气定长波的经向传播影响了越赤道气流的强弱,进而对亚澳冬季季风系统降水产生了影响.研究表明, 绿化使低层南北半球越赤道气流略微增强,增加了北半球冬季寒潮深入南半球内部的几率,并引起了澳洲大陆北部沿岸的气流明显增强,季风槽南移,降雨带区域性的南移,增加了气旋干扰深入内陆的几率,降水发生的频率增多; 沙漠化则引起澳洲大陆增温显著,由于局地下沉运动抑制了对流,造成了陆上降水的减少,通过波的外传,引起了100°～110°E和120°～130°E的低层越赤道气流的变弱和澳大利亚季风槽降水的减少.Influences induced by afforestation and desertification on Australian local climate and largescale circulation, as well as monsoon rainfall in winter were studied by sensitive experiments of afforestation and desertification using CCM3. Results indicated change of land cover has distinct impact on regional climate, Afforestation in mid-west part of Australian land can result in remarkable decrease of air temperature in east of desertification, however desertification can result in notable increase of air temperature in centre Australian land, the change of which is influenced by surrounding ocean environment, Comparing with regional climate change induced by the decrease of local water vapor content in desertification experiment, more marked influence on regional climate induced by increase of water vapor content in afforestation experiment, The change of rainfall has relation with convection strength and production of deviation circulation. The local thermal and moist status can affect the cross-equator air flow and monsoon rainfall by transportation of general atmospheric circulation along longitude direction, Results also showed that afforestation make cross-equatorial flow stronger and increase the possibility of cold wave from Northern Hemisphere invading inland over Southern Hemisphere, whereas desertification will make the cross-equatorial flow weaker in range of 100°～110°E and 120°～130°E in lower troposphere, which will further influence Australian monsoon rainfall in winter. The afforestation resulted in strength of flow along northern inshore of Australian land, and monsoon trough moved to south, as well as the movement of rain-belt, and increase the change of precipitation, while in desertification experiment, the north flow weaker, along with the northern flow, which caused the less water vapor transmitted and less rainfall in monsoon - trough.

关 键 词：亚澳冬季风 植被覆盖变化 越赤道气流 大气环流模式CCM3 

分 类 号：P425.42[天文地球—大气科学及气象学]