10th International Aerosol Conference
September 2 - September 7, 2018
America's Center Convention Complex
St. Louis, Missouri, USA

Abstract View


Single Scattering Albedo of Homogeneous, Spherical Particles in the Transition Region

HANS MOOSMULLER, Christopher Sorensen, Desert Research Institute

     Abstract Number: 1347
     Working Group: Aerosol Physics

Abstract
The aerosol single scattering albedo (SSA) is the dominant intensive particle parameter determining the aerosols radiative forcing in the earth’s atmosphere [1-3]. We use Mie theory to examine the behavior of SSA as a function of size parameter x and complex refractive index m for homogeneous spherical particles. Previously, we investigated the limiting cases of the small particle limit (x << 1) and the large particle limit (x >> 1), where SSA is proportional to x3 and independent of the size parameter x, respectively [4]. In between these cases lies the transition (or peak) region, where SSA transitions from the small to the large particle regime and, for sufficiently small imaginary parts of the refractive index, shows one or more peaks.

Here, we investigate the behavior of SSA in the transition region including conditions on the complex refractive index for peak formation, peak location, and general properties of SSA as function of size parameter.

References
[1] Chýlek, P. and J. Wong (1995): Effect of Absorbing Aerosol on Global Radiation Budget. Geophys. Res. Lett. 22, 929-931.
[2] Hassan, T., H. Moosmüller, and C. E. Chung (2015): Coefficients of an Analytical Aerosol Forcing Equation Determined with a Monte-Carlo Radiation Model. J. Quant. Spectrosc. Radiat. Transfer, 164, 129-136.
[3] Moosmüller, H. and J. A. Ogren (2017): Parameterization of the Aerosol Upscatter Fraction as Function of the Backscatter Fraction and Their Relationships to the Asymmetry Parameter for Radiative Transfer Calculations. Atmosphere, 8(8), 133, doi:10.3390/atmos8080133.
[4] Moosmüller, H. and C. M. Sorensen (2018): Small and Large Particle Limits of Single Scattering Albedo for Homogeneous, Spherical Particles. J. Quant. Spectrosc. Radiat. Transfer, 204, 250-255.