Direct oceanic emissions unlikely to account for the missing source of atmospheric carbonyl sulfide
Direct oceanic emissions unlikely to account for the missing source of atmospheric carbonyl sulfide
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DOI：
10.5194/acp-17-385-2017
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发表时间：
2017-01-10
影响因子：
6.3
通讯作者：
Kruger, Kirstin
中科院分区：
文献类型：
--
作者：
Lennartz, Sinikka T.;Marandino, Christa A.;Kruger, Kirstin
气候活跃的痕量气体--羰基硫化物(OCS)是大气中含量最丰富的硫磺气体。目前建议在其大气预算中缺少一个来源，这是由于植被汇向上修正造成的。已经提出了热带海洋排放的建议，以弥补由此造成的大气预算缺口。我们提出了一种自下而上的方法，包括(I)在热带大西洋、太平洋和印度洋的表层水域新观测到的OCS，以及(Ii)进一步改进的全球箱模型，以表明OCS的直接排放不太可能解释缺失的源。BOX模型表明，相对于整个热带海洋地区的海洋表层水，表层水的饱和程度较低，此外，全球海洋表层水的年直接排放量远低于自上而下的估算结果。此外，我们还讨论了CS2和二甲基硫化物(DMS)间接排放的潜力，以解释大气收支缺口。这种对海洋排放量的自下而上的估计意味着使用海洋大陆架作为全球陆地二氧化碳吸收的替代指标，目前全球陆地二氧化碳吸收受到大气海洋海洋大陆架来源和汇的不充分量化的阻碍。
The climate active trace-gas carbonyl sulfide (OCS) is the most abundant sulfur gas in the atmosphere. A missing source in its atmospheric budget is currently suggested, resulting from an upward revision of the vegetation sink. Tropical oceanic emissions have been proposed to close the resulting gap in the atmospheric budget. We present a bottom-up approach including (i) new observations of OCS in surface waters of the tropical Atlantic, Pacific and Indian oceans and (ii) a further improved global box model to show that direct OCS emissions are unlikely to account for the missing source. The box model suggests an undersaturation of the surface water with respect to OCS integrated over the entire tropical ocean area and, further, global annual direct emissions of OCS well below that suggested by top-down estimates. In addition, we discuss the potential of indirect emission from CS2 and dimethylsulfide (DMS) to account for the gap in the atmospheric budget. This bottom-up estimate of oceanic emissions has implications for using OCS as a proxy for global terrestrial CO2 uptake, which is currently impeded by the inadequate quantification of atmospheric OCS sources and sinks.