loading page

Evaluation of Higher-order Quadrature Schemes in Improving Computational Efficiency for Orientation-averaged Single-Scattering Properties of Nonspherical Ice Particles
  • +2
  • Ines FENNI,
  • Kwo-Sen Kuo,
  • Mark Haynes,
  • Ziad S Haddad,
  • Hélène Roussel
Ines FENNI
UCLA, UCLA

Corresponding Author:[email protected]

Author Profile
Kwo-Sen Kuo
National Aeronautics and Space Administration (NASA), National Aeronautics and Space Administration (NASA)
Author Profile
Mark Haynes
Jet Propulsion Laboratory, Jet Propulsion Laboratory
Author Profile
Ziad S Haddad
Jet Propulsion Lab (NASA), Jet Propulsion Lab (NASA)
Author Profile
Hélène Roussel
Sorbonne University, Sorbonne University
Author Profile

Abstract

We evaluate several high-order quadrature schemes for accuracy and efficacy in obtaining orientation-averaged single-scattering properties (SSPs). We use the highly efficient MIDAS to perform electromagnetic scattering calculations to evaluate the gain in efficiency from these schemes. MIDAS is shown to be superior to DDSCAT, a popular discrete dipole approximation (DDA) method. This study is motivated by the fact that quality physical precipitation retrievals rely on using accurate orientation-averaged SSPs derived from realistic hydrometeors as input to radiative transfer Models (RTMs). The DDA has been a popular choice for single-scattering calculations, due to its versatility with respect to target geometry. However, being iterative-solver-based (ISB), the most used DDA codes, e.g. DDSCAT and ADDA, must solve the scattering problem for each orientation of the target separately. As the size parameter and geometric anisotropy of the hydrometeor increase, the number of orientations needed to obtain accurate orientation-averages can increase drastically and so does the computation cost incurred by the ISB-DDA methods. MIDAS is a Direct-Solver-Based (DSB) code, its decomposition of the original large matrix with a high rank into multiple more manageable smaller matrices of lower ranks makes it much more computationally efficient while maintaining excellent accuracy. In addition, direct solvers consider all requested orientations at once, giving MIDAS further advantage over popular ISB-DDA methods. MIDAS, when combined with high-order quadrature for orientation averaging, can be greater than three orders of magnitude more efficient in obtaining RTM-ready SSPs of complex-shaped hydrometeors than existing ISB-DDA methods, with the native quadrature schemes they offer.
16 Jun 2021Published in Journal of Geophysical Research: Atmospheres volume 126 issue 11. 10.1029/2020JD034172