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dc.contributor.authorScarnato, B.V.
dc.contributor.authorChina, S.
dc.contributor.authorNielsen, K.
dc.contributor.authorMazzoleni, C.
dc.date2015
dc.date.accessioned2016-08-02T19:43:57Z
dc.date.available2016-08-02T19:43:57Z
dc.date.issued2015
dc.identifier.citationScarnato, B. V., et al. "Perturbations of the optical properties of mineral dust particles by mixing with black carbon: a numerical simulation study." Atmospheric Chemistry and Physics v.15. no.12 (2015): pp. 6913-6928.en_US
dc.identifier.urihttp://hdl.handle.net/10945/49510
dc.descriptionThe article of record as published may be found at http://dx.doi.org/10.5194/acp-15-6913-2015en_US
dc.description.abstractField observations show that individual aerosol particles are a complex mixture of a wide variety of species, reflecting different sources and physico-chemical transformations. The impacts of individual aerosol morphology and mixing characteristics on the Earth system are not yet fully understood. Here we present a sensitivity study on climate-relevant aerosols optical properties to various approximations. Based on aerosol samples collected in various geographical locations, we have observationally constrained size, morphology and mixing, and accordingly simulated, using the discrete dipole approximation model (DDSCAT), optical properties of three aerosols types: (1) bare black carbon (BC) aggregates, (2) bare mineral dust, and (3) an internal mixture of a BC aggregate laying on top of a mineral dust particle, also referred to as polluted dust. DDSCAT predicts optical properties and their spectral dependence consistently with observations for all the studied cases. Predicted values of mass absorption, scattering and extinction coefficients (MAC, MSC, MEC) for bare BC show a weak dependence on the BC aggregate size, while the asymmetry parameter (g) shows the opposite behavior. The simulated optical properties of bare mineral dust present a large variability depending on the modeled dust shape, confirming the limited range of applicability of spheroids over different types and size of mineral dust aerosols, in agreement with previous modeling studies. The polluted dust cases show a strong decrease in MAC values with the increase in dust particle size (for the same BC size) and an increase of the single scattering albedo (SSA). Furthermore, particles with a radius between 180 and 300 nm are characterized by a decrease in SSA values compared to bare dust, in agreement with field observations. This paper demonstrates that observationally constrained DDSCAT simulations allow one to better understand the variability of the measured aerosol optical properties in ambient air and to define benchmark biases due to different approximations in aerosol parametrization.en_US
dc.description.sponsorshipResearch Initiation Program at the Naval Postgraduate schoolen_US
dc.description.sponsorshipNASA (grant NNX13AN68H)en_US
dc.description.sponsorshipNSF (grant AGS-1110059)en_US
dc.description.sponsorshipDOE (grants DE-SC0006941 and DE-SC0010019)en_US
dc.format.extent16 p.en_US
dc.publisherCopernicus Publicationsen_US
dc.rightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.en_US
dc.titlePerturbations of the optical properties of mineral dust particles by mixing with black carbon: a numerical simulation studyen_US
dc.typeArticleen_US
dc.contributor.corporateNaval Postgraduate School (U.S.)en_US
dc.description.funderResearch Initiation Program at the Naval Postgraduate schoolen_US
dc.description.funderNASA (grant NNX13AN68H)en_US
dc.description.funderNSF (grant AGS-1110059)en_US
dc.description.funderDOE (grants DE-SC0006941 and DE-SC0010019)en_US


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