1984~2000年印度洋与中国地区上空对流层中上层及平流层气溶胶变化和输送特征

CHARACTERISTICS OF CHANGE AND TRANSPORTOF AEROSOLS IN THE MIDDLE AND UPPER TROPOSPHERE AND STRATOSPHERE OVER INDIAN OCEAN AND CHINA IN 1984-2000

  • 摘要: 利用美国SAGE II (Stratospheric Aerosol and Gas Experiment II)卫星最新版(6.0版)1.020 μm通道逐日气溶胶消光系数资料,得出了对流层中上层及平流层(10 km以上高度)气溶胶光学厚度的平均分布和变化特征。结果表明:气溶胶光学厚度在低纬度大,在印度洋的岛屿上空有三个高值中心,气溶胶光学厚度高值中心与对流层中上层的上升气流的高值中心相对应。与17年(1984~2000年)年平均相比,近6年(1995~2000年)孟加拉湾至青藏高原东南部上空气溶胶光学厚度明显增加;中国东部地区上空气溶胶光学厚度增加,中西部地区则减小。气溶胶光学厚度存在三个经向的增加带和两个经向的减小带。中纬度与赤道之间的布鲁尔-多普森环流(Brewer-Dobson Circulation)带来的低层大气与对流层中上层及平流层之间的气溶胶输送是导致气溶胶这种经向一致变化的主要因素。气溶胶的这种输送产生的近地面大气污染物向中上层大气输送有可能产生重要的气候变化。

     

    Abstract: The latest version (6.0) daily aerosols extinction dataset of the 1.020 μm zone SAGE Ⅱ was analyzed, and the characteristics of transport and change of aerosol optical depth in the middle and upper troposphere and the stratosphere (above 10 kilometer high) was given. The results show that aerosol optical depth in the low latitude is larger than that in the higher latitude. There are three high value centers over the island in Indian Ocean. The high value centers of aerosol optical depth are corresponding with the high value of up flow in the middle and upper troposphere. Comparing to the average of the 17 years (1984—2000), latest 6 years the aerosol optical depth from the Bengal Bay to the southeast of the Tibetan Plateau increases distinctively. Contrary to the middle and eastern of China, the aerosol optical depth over the eastern of China is decreased. Aerosol optical depth has three longitudinal increasing zones and two longitudinal decreasing zones. The Brewer-Dobson circulation between the middle latitude and the equator area causes these longitudinal change zones. This transporting of aerosols between the lower layer and middle and upper layer atmosphere may cause important climate change。

     

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