地形效应引起的局地扰动对华南降水预报的影响研究  

INFLUENCE OF LOCAL PERTURBATION INDUCED BY OROGRAPHIC EFFECT ON FORECAST OF PRECIPITATION IN SOUTH CHINA

作　　者：徐道生[1] 陈子通[1] 谢东东[2] 戴光丰[1] 钟水新[1] 

机构地区：[1]中国气象局广州热带海洋气象研究所/广东省区域数值天气预报重点实验室 [2]中国人民解放军95915部队气象台

出　　处：《热带气象学报》2015年第2期173-181,共9页Journal of Tropical Meteorology

基　　金：广东省科技计划项目(2011A032100006;2012A061400012);公益性行业(气象)科研专项(GYHY20120610);适用于高分辨率模式的对流参数化方案研究(144040990010);对流参数化与微物理过程的耦合研究(144040990019)共同资助

摘　　要：利用中尺度模式对一次华南强降水过程进行模拟分析发现，模式对南岭．武夷山地区的降水存在漏报或预报强度偏弱的现象。通过与提前12h预报结果的对比看出，引起这种预报误差的主要原因在于本次预报的模式初值中未包含地形强迫造成的小尺度局地扰动信息。对地形重力波拖曳和阻塞流拖曳参数化方案的比较发现，阻塞流拖曳力强度明显强于地形重力波拖曳，它有可能导致雨带位置偏离实况。一系列的初值敏感性试验结果表明，南岭-武夷山地区上空850~500hPa的风场扰动增量对改进本次降水预报效果的影响最关键。A heavy precipitation process that happened in south China is simulated with a regional mesoscale model. It was found that precipitation in Nanling-Wuyi Mountains is much underestimated or completely missed. Comparisons with the forecast made 12 hours before demonstrated that the bias of precipitation forecast is caused by local perturbation induced by the orographic effect. Testing of GWDO （Gravity Wave Drag induced by subgrid-scale Orography） and MBD （Mountain Blocking Drag） scheme showed that the drag produced by MBD is much stronger than by GWDO, which will cause significant error in precipitation forecast. A series of sensitive tests show that the perturbation of wind between 850-500 hPa in Nanling-Wuyi Mountains is the most critical factor in improving precipitation forecast.

关 键 词：地形效应 扰动 中尺度模式 华南降水 

分 类 号：P456.7[天文地球—大气科学及气象学]