Structure of moist layer and sources of water over the southern region far from the Meiyu/Baiu front
Structure of moist layer and sources of water over the southern region far from the Meiyu/Baiu front
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DOI：
10.2151/jmsj.83.137
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发表时间：
2005-04
影响因子：
3.1
通讯作者：
T. Shinoda;H. Uyeda;K. Yoshimura
中科院分区：
文献类型：
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作者：
T. Shinoda;H. Uyeda;K. Yoshimura
我们利用GAME（GEWEX亚洲季风实验，GEWEX：全球能源和水循环实验）再分析数据研究了远离梅雨/白乌锋的南部地区潮湿层的结构和水源。 1998年7月4日至15日期间，梅雨/白雨锋位于中国北部（黄河流域）和朝鲜半岛上空。中国大陆平原地区（112°E线东部地区）和东海地区此时期都有非常湿润的气团；该地区总降水量约为45 kgm−2。然而，这些潮湿层的结构却截然不同。中国大陆上空湿润层很深，达到600 hPa。另一方面，东海湿层较浅，厚度可达800 hPa。这种湿层结构的差异可以归因于中国大陆白天湿对流混合层的发展和浅对流云的产生，这是由于地表提供了丰富的潜热和中等感热通量。我们还使用有色水分分析（CMA）检查了梅雨锋的水源。虽然形成中国大陆深层湿润层的水汽主要来自亚洲夏季风上游地区，包括印度洋、中南半岛和南海，但当梅雨锋位于中国北部地区时，中国大陆东南部地区的水汽贡献率超过了总降水量的15%。这表明中国东南部陆地表面被视为梅雨锋的主要水源地。
We investigate the structure of a moist layer and sources of water in the southern region far from the Meiyu/Baiu front using GAME (GEWEX Asian Monsoon Experiment, GEWEX: Global Energy and Water Cycle Experiment) reanalysis data. In the period from July 4 to 15, 1998, the Meiyu/Baiu front was located over northern China (the Yellow River Valley) and the Korean Peninsula. Both regions over the plain area of mainland China (the eastern region of 112°E line) and the East China Sea have very moist air masses in this period; the total precipitable water over the regions is about 45 kgm−2. However, the structure of these moist layers is quite different. The moist layer over mainland China is deep, reaching 600 hPa. On the other hand, the moist layer over the East China Sea is shallow, with a thickness of up to 800 hPa. This difference in the structure of the moist layers can be attributed to the development of a moist convective mixing layer and the generation of shallow convective clouds in the daytime over mainland China, as a result of the supply of abundant latent and moderate sensible heat fluxes from the land surface.We also examine the sources of water supplied into the Meiyu front using Colored Moisture Analysis (CMA). Though water vapor to generate the deep moist layer over mainland China is mainly transported from the upstream regions of the Asian summer monsoon, which include the Indian Ocean, the Indochina Peninsula, and the South China Sea, the rate of the contribution of water from the southeastern region of mainland China is over 15% of the total precipitable water, when the Meiyu front is located over northern China. This shows that the land surface over southeastern China is regarded as a major source of water to the Meiyu front.