Identifying Chemical Aerosol Signatures using Optical Suborbital Observations: How much can optical properties tell us about aerosol composition?

Abstract. Improvements in air quality and Earth’s climate predictions require improvements of the aerosol speciation chemical transport models, using observational constraints. Aerosol (e.g., organic aerosols, black carbon, sulfate, nitrate, ammonium, dust or sea salt) is typically determined situ instrumentation. Continuous, routine surface network composition measurements are not uniformly widespread over globe. Satellites, on other hand, can provide a maximum coverage horizontal vertical atmosphere but observe optical properties (and speciation) based remote sensing Combinations satellite-derived inform mass types (AMTs e.g., clean marine, dust, polluted continental). However, these AMTs subjectively defined, might often be misclassified hard to relate critical parameters that need refined models. In this paper, we derive more directly related sources hence speciation. They characterized, derived simultaneous gas-phase, instruments same aircraft during Study Emissions Atmospheric Composition, Clouds, Climate Coupling by Regional Surveys (SEAC4RS, US, summer 2013). First, prescribe well-informed display distinct signatures act as training AMT dataset. These observations reduce errors ambiguities selection We also investigate relative skill various combinations define how much capture dominant find for biomass burning (from agricultural wildfires), biogenic dust-influence AMTs. Useful characterize extinction angstrom exponent (EAE), single scattering albedo, difference albedo two wavelengths, absorption coefficient, (AAE), real part refractive index (RRI). all four studied when prescribed mostly airborne gas measurements, successfully extracted from at least three EAE, AAE RRI) US SEAC4RS. optically classifications BB fires include large percentage misclassifications limit usefulness results relating those classes. The technique presented study suitable develop representative, robust diverse source-based database. This database could then used retrievals existing future suborbital instruments/networks. Ultimately, it has potential broader data set evaluate models than currently available direct measurements. illustrates essential explore datasets bridge different AMTs, before implementation spaceborne missions next generation Earth Observing System (EOS) satellites addressing Aerosol, Cloud, Convection Precipitation (ACCP) designated observables).