基于TES反演数据的亚洲中低纬度地区大气水汽δD的时空分布

Spatial-temporal distribution of δD in atmospheric water vapor by using TES retrievals over middle to low latitudes in Asia

利用搭载在Aura卫星上的TES观测仪所反演的2004年8月至2010年12月逐日HDO、H2O、气温以及GNIP等资料,对亚洲中低纬度地区大气水汽中δD的时空分布特征、水汽δD与气温、水汽量的关系以及与降水同位素的关系进行了研究。从空间上来看:大气水汽、降水δD整体上表现出随纬度升高而降低的趋势,同时低纬度的西太平洋暖池以东和西亚地区形成了两个高值中心,中纬度的青藏高原和西太平洋形成了两个低值中心。从季节变化来看:陆地上水汽δD表现出暖季的高值与冷季的低值交替出现,海洋上这种变化则不明显,同时,可以看到水汽δD的季节变化与低纬度陆地上降水δD的暖季低、冷季高正好相反;中纬度大陆上水汽δD的最大值出现在气温最高的夏季;低纬度的印度半岛、中南半岛的最大值出现在季风暴发前的春季。就水汽中δD与气温、水汽量关系而言:在中纬度大陆及西亚地区均表现出正相关;在西太平洋暖池处,水汽中δD与气温呈正相关,与水汽量呈负相关。

SSpatial-temporal distribution of water vapor δD, the correlations between water vapor δD and temperature, water vapor amount, and the relationship of water vapor δD with precipitation δD at mid-latitude to low latitudes over Asia are studied by using daily retrievals of H20, HDO, temperature from TES on NASA＇s Aura spacecraft and data from GNIP. In terms of the spatial distribution, both precipitation and water vapor δD decrease with the increasing latitude, and there are two regions with the highest δD values over low latitudes, one in the east of Pacific warm pool and the other in western Asia, while there are two regions with the lowest δD values over the mid latitudes （i.e., the Tibetan Plateau and the western Pacific）. As for the seasonality, water vapor δD is low in the cool season and high in the warm season. This periodical change is significant over the continent but insignificant over the ocean. The highest δD values occur in summer over mid-latitude continent, while the highest δD values comes out before the monsoon season over low-latitude continent （i.e., the India Peninsula and the Indo-China Peninsula）. Referring to the correlations of water vapor δD with temperature and the amount of water vapor, both temperature and the amount of water vapor show positive correlations over the mid-latitude continent and the West Asia, while the Pacific warm pool shows positive and negative correlations for temperature and amount of water vapor with water vapor δD, respectively.