Chemical characteristics of continental outflow from Asia to the troposphere over the western Pacific Ocean during September–October 1991: Results from PEM-West A
Chemical characteristics of continental outflow from Asia to the troposphere over the western Pacific Ocean during September–October 1991: Results from PEM-West A
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DOI：
10.1029/95jd01044
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发表时间：
1996-01
影响因子：
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通讯作者：
R. Talbot;J. Dibb;K. Klemm;J. Bradshaw;S. Sandholm;D. Blake;G. Sachse;J. Collins;B. Heikes;G. Gregory;B. Anderson;H. Singh;D. Thornton;J. Merrill
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文献类型：
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作者：
R. Talbot;J. Dibb;K. Klemm;J. Bradshaw;S. Sandholm;D. Blake;G. Sachse;J. Collins;B. Heikes;G. Gregory;B. Anderson;H. Singh;D. Thornton;J. Merrill
西A太平洋探测飞行任务的一个重要目标是对亚洲大陆西太平洋上空流出的对流层微量气体和气溶胶颗粒进行化学定性。本文概述了1991年9月至10月期间这种外流的化学性质。CO、C2 H6和NOx的垂直分布表明，在海拔低于2 km和8 ~ 12 km处有外流区。在这两个区域中，CO的混合比为十亿分之130体积份（ppbv），C2 H6的混合比为万亿分之1000体积份（pptv），NOx的混合比为万亿分之100 pptv。亚洲工业材料的直接流出在2公里以下的高度是明显的，在那里，卤化碳示踪化合物，如CH 3CCl 3和C2Cl 4增强了约三倍，与老化的太平洋空气相比。在8-12公里高度从亚洲流出到太平洋的物种的来源归属并不简单。在10 km以上的高度有显着的增强NOy，O3，CO，CH 4 SO2，C2 H6，C3 H8，C2 H2，和气溶胶210铅，但没有卤烃工业示踪剂。这些空气质量富含氮相对于硫，并包含C2 H2/CO和C3 H8/C2 H6的比率（分别为1.5和0.1），表明几天前的燃烧排放。目前尚不清楚这些排放是来自亚洲，还是由于对流层区域的高风速（60 - 70 m s−1）而从欧洲迅速输送到该区域。此时亚洲上空的显著气旋活动可能将东南亚生物质燃烧产生的排放或广泛使用各种生物质材料进行烹饪和空间供暖产生的排放输送到对流层上部。显然，对流层上层的排放物是由湿对流系统带到那里的，因为这些气团中的水溶性气体和气溶胶已经耗尽。近9公里的高度有一个明显的区域外流，似乎在亚洲大陆，特别是从东南部地区的生源过程的影响很大。这些气团含有超过1800 ppbv的CH 4，而CO2和OCS则显著减少（分别为349 - 352 ppmv和450 - 500 pptv）。这一特征似乎反映了湿地和稻田的CH 4排放与对流层CO2和OCS的生物圈吸收相一致。
An important objective of the Pacific Exploratory Mission-West A (PEM-West A) was the chemical characterization of the outflow of tropospheric trace gases and aerosol particles from the Asian continent over the western Pacific Ocean. This paper summarizes the chemistry of this outflow during the period September – October 1991. The vertical distributions of CO, C2H6, and NOx showed regions of outflow at altitudes below 2 km and from 8 to 12 km. Mixing ratios of CO were ≈130 parts per billion by volume (ppbv), ≈1000 parts per trillion by volume (pptv) for C2H6, and ≈100 pptv for NOx in both of these regions. Direct outflow of Asian industrial materials was clearly evident at altitudes below 2 km, where halocarbon tracer compounds such as CH3CCl3 and C2Cl4 were enhanced about threefold compared to aged Pacific air. The source attribution of species outflowing from Asia to the Pacific at 8–12 km altitude was not straightforward. Above 10 km altitude there were substantial enhancements of NOy, O3, CO, CH4 SO2, C2H6, C3H8, C2H2, and aerosol 210Pb but not halocarbon industrial tracers. These air masses were rich in nitrogen relative to sulfur and contained ratios of C2H2/CO and C3H8/C2H6 (≈1.5 and 0.1 respectively) indicative of several-day-old combustion emissions. It is unclear if these emissions were of Asian origin, or if they were rapidly transported to this region from Europe by the high wind speeds in this tropospheric region (60 – 70 m s−1). The significant cyclonic activity over Asia at this time could have transported to the upper troposphere emissions from biomass burning in Southeast Asia or emissions from the extensive use of various biomass materials for cooking and space heating. Apparently, the emissions in the upper troposphere were brought there by wet convective systems since water-soluble gases and aerosols were depleted in these air masses. Near 9 km altitude there was a distinct regional outflow that appeared to be heavily influenced by biogenic processes on the Asian continent, especially from the southeastern area. These air masses contained CH4 in excess of 1800 ppbv, while CO2 and OCS were significantly depleted (349 – 352 ppmv and 450 – 500 pptv, respectively). This signature seemingly reflected CH4 emissions from wetlands and rice paddies with coincident biospheric uptake of tropospheric CO2 and OCS.