¹⁴ C-AMS analysis of atmospheric aerosols in coastal regions of Mexico and Cuba: fossil carbon contribution

Radiocarbon analysis of atmospheric particulate matter is a powerful tool for elucidating the apportionment of carbon sources. The radiocarbon content enables the differentiation between fossil-derived carbon, primarily from fossil fuel combustion, and modern carbon, associated with for example, biomass burning. Precise identification of anthropogenic and natural aerosol carbon sources is essential for establishing a robust framework to assess their impact on coastal ecosystems. In this work, we determined the contribution of fossil and modern carbon in aerosols collected in coastal areas of Mexico and Cuba. PM 2.5 fraction was collected in the maritime ports of Veracruz and Manzanillo in Mexico, and PM 10 fraction in Havana in Cuba. The analyses are complemented by elemental characterization and receptor modeling to discern specific contributions to PM mass. The wind climatology analysis was conducted using ERA5 reanalysis data, covering 30 years (1993–2023) and focusing on the summer months to characterize wind patterns at a height of 10 meters. To determine the meteorological conditions during the sampling campaign at the three locations, we have computed site-specific backward air-mass trajectories using the NOAA HYSPLIT model (GDAS meteorological fields). Fossil carbon is an important component of aerosols from maritime ports such as Havana and Veracruz. Manzanillo port exhibited reduced pollutant levels reflecting local wind influence and less regional industrialization and urbanization.