Atmospheric aerosol over the North Atlantic Ocean impacts regional clouds and climate. In this work, we use a set of sun photometer observations of aerosol optical depth (AOD) located on the Graciosa and Cape Verde islands, along with the GEOS‐Chem chemical transport model to investigate the sources of these aerosol and their transport over the North Atlantic Ocean. At both locations, the largest simulated contributor to aerosol extinction is the local source of sea‐salt aerosol. In addition to this large source, we find that signatures consistent with long‐range transport of anthropogenic, biomass burning, and dust emissions are apparent throughout the year at both locations. Model simulations suggest that this signal of long‐range transport in AOD is more apparent at higher elevation locations; the influence of anthropogenic and biomass burning aerosol extinction is particularly pronounced at the height of Pico Mountain, near the Graciosa Island site. Using a machine learning approach, we further show that simulated observations at these three sites (near Graciosa, Pico Mountain, and Cape Verde) can be used to predict the simulated background aerosol imported into cities on the European mainland, particularly during the local winter months, highlighting the utility of background AOD monitoring for understanding downwind air quality.

中文翻译：

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使用基于岛屿的太阳光度计探索模拟气溶胶源和跨北大西洋传输的限制

北大西洋上空的大气气溶胶影响区域云和气候。在这项工作中，我们使用一组太阳光度计对位于格拉西奥萨岛和佛得角群岛的气溶胶光学深度 (AOD) 进行观测，并结合 GEOS-Chem 化学传输模型来研究这些气溶胶的来源及其在北方的传输大西洋。在这两个地点，模拟的气溶胶灭绝的最大贡献者是当地的海盐气溶胶来源。除了这个巨大的来源之外，我们发现与人为、生物质燃烧和粉尘排放的远距离运输一致的特征在这两个地点全年都很明显。模型模拟表明，AOD 中的这种远程传输信号在海拔较高的位置更为明显；人为和生物质燃烧气溶胶灭绝的影响在格拉西奥萨岛遗址附近的皮科山高处尤其明显。使用机器学习方法，我们进一步表明，这三个地点（格拉西奥萨、皮科山和佛得角附近）的模拟观测可用于预测输入欧洲大陆城市的模拟背景气溶胶，特别是在当地冬季。 ，强调了后台 AOD 监测对于了解顺风空气质量的实用性。