摘要
东南亚地区的夏季风在亚洲季风系统中首先爆发后,通过风场与对流场的变化对周边地区造成影响。通过对亚洲近地面层经向水汽通道的研究,发现在前期影响云南雨季开始的早迟最重要的一支南风水汽通道位于孟加拉湾(80～90°E)附近。该南风水汽通道一般在春季开始建立,它的建立有助于夏季风在东南亚地区爆发。在季风建立前,当这一水汽通道中南风水汽输送异常偏强时,相应地中南半岛附近的对流也增强,对应着云南的雨季开始偏早,初夏降水偏多,反之则初夏降水偏少。研究表明,该水汽输送的强弱可以作为预报云南雨季开始期及初夏雨量的一个重要信号。研究还发现,前期赤道中东太平洋的冷海温有利于孟加拉湾经向水汽输送的加强,从而影响到云南的雨季开始和初夏的雨量。
After it first breaks out over the Southeast Asia in the Asian summer monsoon system, summer monsoon over the Southeast Asia affects the peripheral area with varied wind field and convection field. Surface meridional moisture channel in Asia is studied in this paper. The result shows that the meridional moisture channel, which lies around the Bay of Bengal （80～90 °E） , plays a very important role in the rainy season in Yunnan. The meridional moisture channel usually sets up in spring. The establishment of this channel can be helpful for onset of summer monsoon over the Southeast Asia and affects the start of the rainy season in Yunnan. Before the establishment of the summer monsoon over the Southeast Asia, if moisture transportation through the meridional moisture channel is very strong, the convection activity also becomes more active around the Indochina Peninsula and the rainy season begins earlier and amount of the early summer precipitation in Yunnan increases more, and vice versa. The meridional moisture transportation is an important signal that can predict the start of the rainy season and the early summer rainfall in Yunnan. Our study also shows that the previous colder SST in the central-eastern Pacific can help intensify the moisture transportation and consequently affects the rainy season and the early summer rainfall in Yunnan.
出处
《热带气象学报》
CSCD
北大核心
2006年第3期209-216,共8页
Journal of Tropical Meteorology
基金
国家自然科学基金项目(40365001)
关键词
东南亚夏季风
经向水汽输送
云南
雨季
the Southeast Asia summer monsoon： meridional moisture transportation
Yunnan
rainy season
