Theoretical characterization of the radiative properties of dust aerosol for the Air Force combat climatology center point analysis intelligence system

• Main Author: McMillen, John D.
• Other Authors: Durkee, P.A.
• Published: Monterey California. Naval Postgraduate School 2012
• Online Access: http://hdl.handle.net/10945/3629

The Air Force Combat Climatology Center produces an analysis of meteorological conditions in a column over any point on the globe. Currently this analysis does not include aerosol impact on radiative transfer. Instead, the meteorological parameters are used to choose an aerosol representation native to MODTRAN radiative transfer software. This research investigates the impact of dust aerosol on radiative transfer in the 1-5 æm wavelength band. Theoretical radiative transfer properties are calculated for various dust aerosols. The aerosols vary in size distribution and index of refraction. The aerosols also vary in phase functions, extinction coefficients, absorption coefficients, and asymmetry parameters. MODTRAN is used to simulate radiative transfer in the 1-5 æm wavelength band incorporating the various dust aerosols in the bottom 1-2 km of the atmosphere. Radiance values from MODTRAN are converted into brightness temperatures, allowing interpretation of the impact dust aerosol has on remote sensing in this wavelength band. Dust aerosol does impact radiative transfer in the 1-5 æm wavelength band. Brightness temperatures vary by as much as 50 K between no aerosol simulations and certain dust simulations below 3 æm, and can vary by 1 K above 3 æm.