Orographically Anchored El Nino Effect on Summer Rainfall in Central China
Orographically Anchored El Nino Effect on Summer Rainfall in Central China
复制标题
地形锚定的厄尔尼诺现象对华中地区夏季降水的影响
DOI：
10.1175/jcli-d-17-0312.1
复制
发表时间：
2017
影响因子：
4.9
通讯作者：
Huang Gang
中科院分区：
文献类型：
--
作者：
Hu Kaiming;Xie Shang-Ping;Huang Gang
夏季降水的年际变化对中国具有很大的社会经济影响。利用新发布的高分辨率数据集研究了中国的历史降雨变率。这些地形锚定的ENSO影响热点在目前使用的粗分辨率数据集中表现不佳。在厄尔尼诺Niño之后的夏季，热带西北太平洋上空形成了一个异常的反气旋，而西北侧翼的异常西南风通过地形抬升导致中国中部山区降雨增加。在el后Niño夏季，大尺度水汽辐合导致平坦的中国东部其他地区的降水异常，从6月到8月向北移动，在季节平均值中很少。
Year-to-year variations in summer precipitation have great socioeconomic impacts on China. Historical rainfall variability over China is investigated using a newly released high-resolution dataset. The results reveal summer-mean rainfall anomalies associated with ENSO that are anchored by mountains in central China east of the Tibetan Plateau. These orographically anchored hot spots of ENSO influence are poorly represented in coarse-resolution datasets so far in use. In post–El Niño summers, an anomalous anticyclone forms over the tropical northwest Pacific, and the anomalous southwesterlies on the northwest flank cause rainfall to increase in mountainous central China through orographic lift. At upper levels, the winds induce additional adiabatic updraft by increasing the eastward advection of warm air from Tibet. In post–El Niño summers, large-scale moisture convergence induces rainfall anomalies elsewhere over flat eastern China, which move northward from June to August and amount to little in the seasonal mean.