Modeling -band single scattering properties of hydrometeors using discrete-dipole approximation and -matrix method
| Autor: | Sabine Göke, Timo Nousiainen, Karri Muinonen, Jani Tyynelä |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Physics
Radiation 010504 meteorology & atmospheric sciences Scattering business.industry Mie scattering Absorption cross section Discrete dipole approximation 01 natural sciences Atomic and Molecular Physics and Optics Computational physics 010309 optics Dipole symbols.namesake Optics Polarizability 0103 physical sciences symbols T-matrix method Rayleigh scattering business Physics::Atmospheric and Oceanic Physics Spectroscopy 0105 earth and related environmental sciences |
| Zdroj: | Journal of Quantitative Spectroscopy and Radiative Transfer. 110:1654-1664 |
| ISSN: | 0022-4073 |
| DOI: | 10.1016/j.jqsrt.2009.02.020 |
| Popis: | We study the applicability of the discrete-dipole approximation by modeling centimeter (C-band) radar echoes for hydrometeors, and compare the results to exact theories. We use ice and water particles of various shapes with varying water-content to investigate how the backscattering, extinction, and absorption cross sections change as a function of particle radius. We also compute radar parameters, such as the differential reflectivity, the linear depolarization ratio, and the copolarized correlation coefficient. We find that using discrete-dipole approximation (DDA) to model pure ice and pure water particles at the C-band, is a lot more accurate than particles containing both ice and water. For coated particles, a large grid-size is recommended so that the coating is modeled adequately. We also find that the absorption cross section is significantly less accurate than the scattering and backscattering cross sections. The accuracy of DDA can be increased by increasing the number of dipoles, but also by using the filtered coupled dipole-option for the polarizability. This halved the relative errors in cross sections. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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