AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Complex Refractive Index of Hematite in the Visible and Near Visible: A Review
HANS MOOSMULLER, Johann Engelbrecht, Desert Research Institute
Abstract Number: 56 Working Group: Aerosols, Clouds, and Climate
Abstract Hematite (alpha-Fe$_2O$_3) is an iron oxide that generally dominates ambient light absorption by entrained mineral dust in the visible and near-visible spectral region. Therefore, knowledge of its complex refractive index spectrum is critical for calculating mineral dust absorption, scattering, and extinction coefficients and single scattering albedo as needed for determination of sign and magnitude of its direct radiative forcing. Unfortunately, literature values for the complex refractive index as function of wavelength vary greatly, often by more than an order of magnitude for the imaginary part. Here, we review published values in the visible and near-visible spectral region together with methods of determination and attempt to give a recommendation for values that should be used.