Earthdata Forum

I obtained concentrations of atmospheric aerosol black carbon, organic carbon, dust, sea salt, and sulfate from NASA's MERRA-2 M2TMNXAER v5.12.4 product, and calculated surface PM₂.₅ using the recommended formula. Based on this, I classified black carbon, organic carbon, and sulfate as anthropogenic PM₂.₅, while dust and sea salt were categorized as natural PM₂.₅. Is this classification reasonable—either overall or for the anthropogenic PM₂.₅ category specifically? Have other studies used similar classifications?

Hello, thank you for your interest in the MERRA-2 aerosol products! A major contributor to organic carbon, and to a lesser extent, black carbon and sulfate, is biomass burning.Volcanoes also emit sulfur dioxide which forms sulfate aerosol. Therefore, components of all aerosol species in MERRA-2 can have natural sources.