We measured submicron aerosols (PM₁) at a beachfront site in Texas in Spring 2021 to characterize the “background” aerosol chemical composition advecting into Texas and the factors controlling this composition. Observations show that marine “background” aerosols from the Gulf of Mexico were highly processed and acidic; sulfate was the most abundant component (on average 57% of total PM₁ mass), followed by organic material (26%). These chemical characteristics are similar to those observed at other marine locations globally. However, Gulf “background” aerosols were much more polluted; the average non-refractory (NR-) PM₁ mass concentration was 3–70 times higher than that observed in other clean marine atmospheres. Anthropogenic shipping emissions over the Gulf of Mexico explain 78.3% of the total measured “background” sulfate in the Gulf air. We frequently observed haze pollution in the air mass from the Gulf, with significantly elevated concentrations of sulfate, organosulfates, and secondary organic aerosol associated with sulfuric acid. Analysis suggests that aqueous oxidation of shipping emissions over the Gulf of Mexico by peroxides in the particles might potentially be an important pathway for the rapid production of acidic sulfate and organosulfates during the haze episodes under acidic conditions.

中文翻译：

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来自墨西哥湾的海洋亚微米气溶胶：污染和酸性并快速产生硫酸盐和有机硫酸盐

我们于 2021 年春季在得克萨斯州的一个海滨地点测量了亚微米气溶胶 (PM ₁ )，以表征平流进入得克萨斯州的“背景”气溶胶化学成分以及控制该成分的因素。观察表明，来自墨西哥湾的海洋“背景”气溶胶经过高度加工并呈酸性；硫酸盐是最丰富的成分（平均占 PM ₁总质量的 57%），其次是有机物质 (26%)。这些化学特征与在全球其他海洋地点观察到的化学特征相似。然而，海湾“背景”气溶胶的污染要严重得多；平均非耐火 (NR-) PM ₁质量浓度比在其他清洁海洋大气中观察到的质量浓度高 3-70 倍。墨西哥湾上空的人为航运排放解释了海湾空气中测得的“背景”硫酸盐总量的 78.3%。我们经常观察到海湾气团中的雾霾污染，硫酸盐、有机硫酸盐和与硫酸相关的二次有机气溶胶浓度显着升高。分析表明，颗粒中的过氧化物对墨西哥湾航运排放物的水氧化可能是酸性条件下雾霾期间快速产生酸性硫酸盐和有机硫酸盐的重要途径。