National Center for Atmospheric Research, Boulder, CO, USA.
Science. 2010 Apr 30;328(5978):611-3. doi: 10.1126/science.1182274. Epub 2010 Mar 25.
Transport of air from the troposphere to the stratosphere occurs primarily in the tropics, associated with the ascending branch of the Brewer-Dobson circulation. Here, we identify the transport of air masses from the surface, through the Asian monsoon, and deep into the stratosphere, using satellite observations of hydrogen cyanide (HCN), a tropospheric pollutant produced in biomass burning. A key factor in this identification is that HCN has a strong sink from contact with the ocean; much of the air in the tropical upper troposphere is relatively depleted in HCN, and hence, broad tropical upwelling cannot be the main source for the stratosphere. The monsoon circulation provides an effective pathway for pollution from Asia, India, and Indonesia to enter the global stratosphere.
空气从对流层向平流层的输送主要发生在热带地区,与 Brewer-Dobson 环流的上升支有关。在这里,我们利用卫星观测到的氢氰酸(HCN)来识别空气团从地表穿过亚洲季风并深入平流层的输送过程,HCN 是生物质燃烧产生的一种对流层污染物。这一识别的一个关键因素是 HCN 与海洋接触时有很强的汇;热带上对流层的大部分空气相对缺乏 HCN,因此,广泛的热带上升流不可能是平流层的主要源。季风环流为亚洲、印度和印度尼西亚的污染物质进入全球平流层提供了一条有效途径。