A negative feedback between anthropogenic ozone pollution and enhanced ocean emissions of iodine
A negative feedback between anthropogenic ozone pollution and enhanced ocean emissions of iodine
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DOI：
10.5194/acp-15-2215-2015
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发表时间：
2015-01-01
影响因子：
6.3
通讯作者：
Saiz-Lopez, A.
中科院分区：
文献类型：
--
作者：
Prados-Roman, C.;Cuevas, C. A.;Saiz-Lopez, A.
碘化合物从海洋中自然排放，有效地破坏大气臭氧，减少其在对流层中的正辐射强迫效应。实验表明，无机碘的排放取决于对流层臭氧沉积到海洋中的情况，自1850年以来，由于人类活动的影响，臭氧的浓度大幅增加。本文使用一个化学-气候模型来量化目前海洋无机碘排放量，并评估自工业化前时代以来对流层臭氧人为增加对海洋环境中碘自然循环的影响。我们的研究结果表明，人为驱动的对流层臭氧的增强增加了一倍的海洋无机碘排放臭氧与碘化物在海面的反应。随之而来的大气中碘的积累，与工业化前相比，在大陆污染流出地区最多增加了70%，这反过来又加速了具有强烈空间模式的海洋臭氧化学物质的损失。我们认为，这种海洋-大气相互作用代表了一个负的地球化学反馈回路，目前的海洋碘排放量作为臭氧污染及其在全球海洋环境中的辐射强迫的天然缓冲。
Naturally emitted from the oceans, iodine compounds efficiently destroy atmospheric ozone and reduce its positive radiative forcing effects in the troposphere. Emissions of inorganic iodine have been experimentally shown to depend on the deposition to the oceans of tropospheric ozone, whose concentrations have significantly increased since 1850 as a result of human activities. A chemistry-climate model is used herein to quantify the current ocean emissions of inorganic iodine and assess the impact that the anthropogenic increase in tropospheric ozone has had on the natural cycle of iodine in the marine environment since pre-industrial times. Our results indicate that the human-driven enhancement of tropospheric ozone has doubled the oceanic inorganic iodine emissions following the reaction of ozone with iodide at the sea surface. The consequent build-up of atmospheric iodine, with maximum enhancements of up to 70% with respect to pre-industrial times in continental pollution outflow regions, has in turn accelerated the ozone chemical loss over the oceans with strong spatial patterns. We suggest that this ocean-atmosphere interaction represents a negative geochemical feedback loop by which current ocean emissions of iodine act as a natural buffer for ozone pollution and its radiative forcing in the global marine environment.