A REANALYSIS OF CARBONYL SULFIDE AS A SOURCE OF STRATOSPHERIC BACKGROUND SULFUR AEROSOL
A REANALYSIS OF CARBONYL SULFIDE AS A SOURCE OF STRATOSPHERIC BACKGROUND SULFUR AEROSOL
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DOI：
10.1029/95jd00275
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发表时间：
1995-05-20
影响因子：
4.4
通讯作者：
DAVIS, DD
中科院分区：
文献类型：
--
作者：
CHIN, M;DAVIS, DD
本研究调查了硫化羰（OCS）在平流层背景硫气溶胶形成中的重要性。研究的具体问题包括平流层的损失率、进入平流层的净通量以及OCS对平流层背景硫气溶胶的贡献。根据对当前大气中 OCS 测量结果的分析，大气中 OCS 的总量估计为 5.2 Tg。其中，4.63 Tg 位于对流层，0.57 Tg 位于平流层。根据估计的全球 OCS 源强度 1.2 Tg yr(-1)，OCS 的全球大气寿命估计为 4.3 年。使用一维光化学模型，OCS的平流层光化学寿命估计为10年，比其全球大气寿命长2倍多。这些结果表明，大部分输送到平流层的 OCS 返回到对流层，在那里它主要被地表植被吸收。 OCS 氧化产生的平流层背景硫气溶胶经计算为 3.0 x 10(10) gS yr(-1)，比维持平流层背景气溶胶水平所需硫量的最新估计值小 2 至 5 倍。对于这种差异的可能解释包括（1）对非火山背景气溶胶负荷的高估； (2) 低估平流层背景气溶胶的寿命； (3)是否存在其他硫源，如高空飞机排放物； (4) 我们分析中使用的平流层 OCS 数据库存在缺陷，存在重大但未识别的系统错误。
This study investigates the importance of carbonyl sulfide (OCS) in the formation of stratospheric background sulfur aerosol. Specific questions examined include the loss rate in the stratosphere, the net flux into the stratosphere, and the contribution of OCS to the stratospheric background sulfur aerosol. From an analysis of current atmospheric measurements of OCS, the total amount of OCS in the atmosphere is evaluated to be 5.2 Tg. Of this total, 4.63 Tg is in the troposphere and 0.57 Tg in the stratosphere. Based on the estimated global OCS source strength of 1.2 Tg yr(-1), the global atmospheric lifetime of OCS is estimated to be 4.3 years. Using a one-dimensional photochemical model, the stratospheric photochemical lifetime of OCS is estimated to be 10 years, more than 2 times longer than its global atmospheric lifetime. These results suggest that most of the OCS transported into the stratosphere returns to the troposphere where it is mainly taken up by surface vegetation. The production of stratospheric background sulfur aerosol from OCS oxidation is calculated to be 3.0 x 10(10) gS yr(-1), 2 to 5 times smaller than the most recent estimates of the amount of sulfur required to maintain the stratospheric background aerosol level. Possible explanations for this difference include (1) an overevaluation of the nonvolcanic background aerosol burden; (2) an underevaluation of the lifetime of stratospheric background aerosol; (3) the presence of other sulfur sources such as high-altitude aircraft emissions; or (4) that the stratospheric OCS database used in our analysis is flawed with a substantial yet unidentified systematic error.