Ocean‐going ships supply products from one region to another and contribute to the world’s economy. Ship exhaust contains many air pollutants and results in significant changes in marine atmospheric composition. The role of reactive halogen species (RHS) in the troposphere has received increasing recognition and oceans are the largest contributors to their atmospheric burden. However, the impact of shipping emissions on RHS and that of RHS on ship‐originated air pollutants have not been studied in detail. Here, an updated Weather Research Forecasting coupled with Chemistry model is utilized to explore the chemical interactions between ship emissions and oceanic RHS over the East Asia seas in summer. The emissions and resulting chemical transformations from shipping activities increase the level of NO and NO₂ at the surface, increase O₃ in the South China Sea, but decrease O₃ in the East China Sea. Such changes in pollutants result in remarkable changes in the levels of RHS (>200% increase of chlorine; ∼30% and ∼5% decrease of bromine and iodine, respectively) as well as in their partitioning. The abundant RHS, in turn, reshape the loadings of air pollutants (∼20% decrease of NO and NO₂; ∼15% decrease of O₃) and those of the oxidants (>10% reduction of OH and HO₂; ∼40% decrease of NO₃) with marked patterns along the ship tracks. We, therefore, suggest that these important chemical interactions of ship‐originated emissions with RHS should be considered in the environmental policy assessments of the role of shipping emissions in air quality and climate.

中文翻译：

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船舶产生的空气污染物与海洋排放的卤素之间的化学相互作用


远洋船舶将产品从一个地区供应到另一个地区，为世界经济做出贡献。船舶尾气含有多种空气污染物，导致海洋大气成分发生显着变化。活性卤素物质 (RHS) 在对流层中的作用已得到越来越多的认识，海洋是其大气负担的最大贡献者。然而，航运排放对 RHS 的影响以及 RHS 对船舶产生的空气污染物的影响尚未得到详细研究。在这里，利用更新的天气研究预测与化学模型相结合来探索夏季东亚海域船舶排放与海洋 RHS 之间的化学相互作用。航运活动的排放和由此产生的化学转化增加了海表NO和NO ₂的水平，增加了南海的O ₃ ，但减少了东海的O ₃ 。污染物的这种变化导致 RHS 水平发生显着变化（氯增加超过 200%；溴和碘分别减少约 30% 和约 5%）及其分配。丰富的 RHS 反过来又重塑了空气污染物的负荷（NO 和 NO ₂减少约 20%；O ₃减少约 15%）和氧化剂负荷（OH 和 HO ₂减少 >10%；约 40 NO ₃的减少百分比），沿船迹有标记图案。因此，我们建议在船舶排放对空气质量和气候影响的环境政策评估中应考虑船舶排放与 RHS 之间的这些重要化学相互作用。