摘要
利用美国夏威夷大学国际太平洋研究中心的区域气候模式(IPRC-RegCM)进行了一系列的数值试验,研究了青藏高原大地形和海陆热力差异对江南春雨的影响。在控制试验中,模式较好地模拟了3～4月江南春雨雨带及低层大气环流特征,由于受高原绕流作用产生的西南气流和西太平洋反气旋环流西北侧的西南气流的共同影响,在我国的江南地区形成大范围的降水雨带,即江南春雨。当在模式中去除青藏高原大地形后,高原东南侧的西南气流显著减弱,江南春雨雨带强度明显减弱,但由于受到西太平洋反气旋西北侧弱西南气流的影响,我国江南地区仍然维持一个较大的降水雨带。在模式中人为地将110°E以东,20°～35°N纬度带的海洋设置为陆地,即人为地减少海陆热力差异后,模式模拟的江南春雨明显减少。在模式的另一组试验中将海温提前61天,即人为地将海陆热力差异季节转换推迟,模式模拟的江南春雨雨带强度也明显减弱。以上模式模拟结果表明,我国江南春雨的形成不仅与青藏高原大地形有关,而且与东西向海陆热力差异有关。
Based on the regional climate model （IPRC--RegCM） of the University of Hawaii at the International Pacific Research Center, a series of numerical experiments were performed to study the effects of Tibetan Plateau and the sea-land thermal contrast on spring persistent rain. The characteristics of spring persistent rain and the low-level atmospheric circulation in March and April were well simulated in the control experiment. Both the southwest flow generated by Plateau topography and the southwest flow on the northwest side of the western Pacific anti-cyclone circulation result in the wide range of precipitation in the southern China, so-called spring persistent rain. When Tibetan Plateau was removed in the model, the southwest flow in the southwest of Plateau obviously decreased, and the intensity of spring persistent rain significantly reduced. As a result of the southwest flow on the northwest side of the western Pacific anti-cyclone circulation, there was some precipitation in the southern China. When changed the sea to the east of 110°E, 20°-35°N latitude into the land, which reduced the sea-land thermal contrast, the simulated spring persistent rain obviously decreased in the model. When the sea surface temperature was in advance of 61 days in another experiment, which postponed the seasonal transition of the sea-land thermal contrast, the intensity of spring persistent rain also reduced clearly. All the above simulated results indicated that the formation of spring persistent rain was not only connected with the large topography of the Tibetan Plateau but also with the zonal sea-land thermal contrast.
出处
《高原气象》
CSCD
北大核心
2010年第1期99-108,共10页
Plateau Meteorology
基金
国家重点基础研究发展计划项目(2006CB403607)
教育部留学回国人员科研启动基金
江苏省六大人才高峰项目(07-A-012)资助
关键词
江南春雨
高原大地形
海陆热力差异
数值模拟
Spring persistent rain
Tibetan Plateau
Sea-land thermal contrast
Numerical simulation
