摘要
由于模式地形与实际地形存在不同程度偏差,而地形对降水有着重要作用,利用WRFV3.1模式,引入气象站海拔改变模式局地地形方法,针对2008年7月20-22日四川盆地一次强降水过程,分析了地形对数值模式预报效果的影响。结果表明,模式中引入更真实地形使得降水强度增大、强降水中心位置和发生时间有所改善,对流层中低层上升运动和气旋切变显著增加,低涡位置有所改善,由此带来更强的降水和落区改善;改变单点地形高度后,其上空气象要素较周边地区都有所变化,随着模式地形高度的改变其幅度不断增加,气象要素变化也更为显著;引入更真实地形使得降水中心增湿、增温和降低高度特征非常明显,气象要素的变化有利于地形改变后低值系统的加强和降水强度的增强。单点地形高度改变可引起初始时刻局地气象要素的微小偏差,但随着积分时间增长,偏差则进一步加大。在保证模式积分稳定的前提下,提出了通过一些关键点引入实际地形高度,从而改进模式的预报效果,特别是降水预报效果的一种地形处理思路。
Because of the terrain model and real terrain have different degree of deviations, and the terrain on precipitation plays an important role. Using WRFV3.1 model, the influence of topography on the numerical model forecast effect was analyzed as to an heavy precipitation in Sichuan basin on 20-22 July 2008 through the meteorological station elevation changing the model grid point terrain height method and introduction of the more realistic terrain model. The results show that the more real terrain in model is introduce to increase the intensity of precipitation, location and occurring time of severe precipitation center are improved; the ascending motion and cyclonic shear in middle and lower troposphere increased significantly, the vortex position is improved, which result in the improvements of severe precipitation location and occurring time. The changing of single point of terrain height cause the above meteorological elements have changed than the surrounding areas. The variation of meteorological element is more remarkable with the increasing of terrain height change in model. The more real terrain makes the characteristics of the humidity increasing, height decreasing and temperature increasing are more significant. Variations of meteorological elements are in favor of low value system strengthening and precipitation intensity increasing after the topography change. The change of single point of terrain height cause a slight deviation of initial local meteorological elements, the deviation further increases with integration time. The regional pattern, in order to ensure the integral stability of the model, the real terrain height is introduced through some key points to improve the prediction effect, especially a terrain processing idea of precipitation prediction.
出处
《高原气象》
CSCD
北大核心
2013年第6期1546-1556,共11页
Plateau Meteorology
基金
国家自然科学基金项目(40775032)
公益性行业(气象)科研专项(GYHY201206039)
国家重点基础研究发展计划(973计划)(2012CB417200)
西南区域气象中心重大项目"西南区域数值预报模式发展与业务系统建设"(2010-01)
关键词
青藏高原东侧
低涡
强降水
数值试验
地形影响
East side of Qinghai-Xizang Plateau, Low vortex, Heavy rainstrom, Numerical test, Terrain affection
作者简介
何光碧（1961-），女，四川人，正研级高工，主要从事数值预报技术开发应用和高原气象研究E-mail：hegb-gaoyuansu06@163．com
