Near equatorial CO and O3 profiles over the Indian Ocean during the winter monsoon: High O3 levels in the middle troposphere and interhemispheric exchange
Near equatorial CO and O3 profiles over the Indian Ocean during the winter monsoon: High O3 levels in the middle troposphere and interhemispheric exchange
复制标题
冬季季风期间印度洋上空赤道附近的 CO 和 O3 剖面：对流层中部的高 O3 水平和半球间交换
DOI：
10.1029/2001jd001126
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发表时间：
2002
影响因子：
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通讯作者：
J. Lelieveld
中科院分区：
文献类型：
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作者：
Jonathan Williams;H. Fischer;S. Wong;P. Crutzen;M. Scheele;J. Lelieveld
[1]1999年1月至3月，一架配备各种化学仪器的Citation喷气式飞机参加了印度洋实验。在冬季风期间（12月至3月），印度洋上的热带辐合带（ITCZ）位于10°S和赤道之间，有效地将污染的北方半球与相对原始的南半球分开。这里分析的是四个垂直廓线（0.5-12.5公里）的CO，O3混合比，和相对湿度，北部和南部的ITCZ。从这些配置文件和伴随的后向轨迹分析，我们确定了两种可能的机制，在热带对流层中部观察到的干燥，臭氧丰富的平流层影响的空气流入。第一种是与北方半球副热带急流有关的快速平流和下沉。第二个是与南半球热带气旋之前的下沉有关。此外，高混合比的CO在北方半球边界层空气和南半球中层大气被解释为一种情况下，半球间的交换，导致污染物水平升高，在8- 10公里的高度范围内的南半球。
[1] Between January and March 1999, a Citation jet aircraft equipped with a variety of chemical instrumentation took part in the Indian Ocean Experiment (INDOEX). During the winter monsoon (December–March), the Intertropical Convergence Zone (ITCZ) over the Indian Ocean lies between 10°S and the equator, effectively dividing the polluted Northern Hemisphere from the relatively pristine Southern Hemisphere. Analyzed here are four vertical profiles (0.5–12.5 km) of CO, O3 mixing ratios, and relative humidity, north and south of the ITCZ. From these profiles and accompanying back-trajectory analyses, we identify two possible mechanisms for the influx of dry, ozone-rich stratospherically influenced air observed in the middle tropical troposphere. The first involves rapid advection and subsidence of air associated with the subtropical jet stream in the Northern Hemisphere. The second is associated with subsidence ahead of a tropical cyclone in the Southern Hemisphere. Moreover, high mixing ratios of CO in Northern Hemisphere boundary layer air and the Southern Hemisphere middle atmosphere are interpreted as a case of interhemispheric exchange, leading to elevated levels of pollutants in the 8- to 10-km altitude range of the Southern Hemisphere.