AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Measured In Situ Mineral Dust Absorption Spectra
Patricia Razafindrambinina, JAMES RADNEY, Christopher Zangmeister, National Institute of Standards and Technology
Abstract Number: 784 Working Group: Aerosols, Clouds, and Climate
Abstract Depending upon the locality, mineral dust aerosols generated from wind-blown soils can represent a significant fraction of local aerosol mass loadings. Further, these aerosols are capable of significantly affecting local energy budgets and hence radiative forcings. However, little is known about the absorption spectra of these particles. Here, we will present laboratory-measured absorption spectra of aerosolized soil samples from locations across the United Sates (CA, IA, MD and MN) with land uses encompassing agriculture, forest and dirt road surfaces. Spectra were collected using a photoacoustic spectrometer with both a supercontinuum laser with a tunable wavelength and bandwidth filter and a diode laser allowing spectra to be measured from λ = 405 nm to 840 nm. We find that the measured spectra can be broadly grouped as either red clay-like or brown/gray dirt-like possessing Absorption Angstrom Exponents of > 4 or ≈ 3.5, respectively.