A global-scale map of isoprene and volatile organic iodine in surface seawater of the Arctic, Northwest Pacific, Indian, and Southern Oceans
A global-scale map of isoprene and volatile organic iodine in surface seawater of the Arctic, Northwest Pacific, Indian, and Southern Oceans
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DOI：
10.1002/2014jc010519
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发表时间：
2015-06-01
影响因子：
3.6
通讯作者：
Yokouchi, Yoko
中科院分区：
文献类型：
--
作者：
Ooki, Atsushi;Nomura, Daiki;Yokouchi, Yoko
2008-2012年期间，在北极西部、西北太平洋、印度洋和南大洋测量了表层海水中的异戊二烯（C5 H8）和三种挥发性有机碘化合物（VOI：CH 3 I、C2 H5 I和CH 2ClI）。这些化合物被认为在排放后的海洋大气化学中起着重要的作用。使用在线平衡气相色谱质谱仪以高时间分辨率（1-6小时间隔）进行测量。C5 H8在高生产力的过渡沃茨和富营养化的热带沃茨中最丰富。叶绿素a标准化的C5 H8产生率在温暖的亚热带和热带沃茨中较高，表明在温暖的沃茨的生物群落中存在C5 H8的高排放源。高浓度的三个VOI在高生产力的过渡水是由于生物生产。对于CH 3 I，最高浓度广泛分布在贫营养亚热带西北太平洋的盆地地区，可能是由于光化学生产和/或浮游植物的高排放率。相反，在亚热带沃茨的C2 H5 I的最低浓度归因于光化学去除。冬季楚科奇海陆架斜坡区和西北太平洋过渡沃茨CH 2ClI浓度的增加表明，区域上升流或冬季冷却与次表层沃茨的垂直混合作用增加了表层CH 2ClI浓度。海-气通量计算结果表明，CH 2ClI通量在陆棚-坡地的三个VOI中最高，CH 3 I通量在盆地地区最高。
Isoprene (C5H8) and three volatile organic iodine compounds (VOIs: CH3I, C2H5I, and CH2ClI) in surface seawater were measured in the western Arctic, Northwest Pacific, Indian, and Southern Oceans during the period 2008-2012. These compounds are believed to play an important role in the marine atmospheric chemistry after their emission. The measurements were performed with high time-resolution (1-6 h intervals) using an online equilibrator gas chromatography mass spectrometer. C5H8 was most abundant in high-productivity transitional waters and eutrophic tropical waters. The chlorophyll-a normalized production rates of C5H8 were high in the warm subtropical and tropical waters, suggesting the existence of a high emitter of C5H8 in the biological community of the warm waters. High concentrations of the three VOIs in highly productive transitional water were attributed to biological productions. For CH3I, the highest concentrations were widely distributed in the basin area of the oligotrophic subtropical NW Pacific, probably due to photochemical production and/or high emission rates from phytoplankton. In contrast, the lowest concentrations of C2H5I in subtropical waters were attributed to photochemical removal. Enhancement of CH2ClI concentrations in the shelf-slope areas of the Chukchi Sea and the transitional waters of the NW Pacific in winter suggested that vertical mixing with subsurface waters by regional upwelling or winter cooling acts to increase the CH2ClI concentrations in surface layer. Sea-air flux calculations revealed that the fluxes of CH2ClI were the highest among the three VOIs in shelf-slope areas; the CH3I flux was highest in basin areas.