Ludwig-Maximilians-Universität
Fakultät für Physik, Meteorologisches Institut
Theresienstrasse 37, 80333 München
Phone: +49 89 21804098, Fax: +49 89 2805508
libRadtran - library for radiative transfer - is a collection of C and Fortran functions and programs for calculation of solar and thermal radiation in the Earth's atmosphere. The package is freely available at http://www.libradtran.org. |
ARTS is a radiative transfer model for the thermal, in particular millimeter and sub-millimeter spectral range which is freely available at http://radiativetransfer.org. |
MYSTIC is a Monte Carlo radiative transfer solver for solar and thermal radiation, which is included in the libRadtran radiative transfer package. It is used for radiative transfer simulations in three-dimensional cloudy atmospheres. Polarization and spherical geometry can be considered without approximations. |
Scattering by molecules, aerosols and cloud particles polarizes solar radiation. Therefore, the polarization state includes charateristic information about the atmospheric composition, which is used for remote sensing of the atmosphere. Scalar radiative transfer modelling is well established and well validated radiative transfer models exist. Recently, several polarized radiative transfer models have been developed. The International working group on Polarized Radiative Transfer (IPRT) aims to validate these models by model intercomparison projects and by providing benchmark results. |
Multi-spectral multi-angle polarized observations from the ground, from air-plane or from satellite may be used to retrieve cloud and aerosol optical and microphysical properties. E.g., the polarization of the cloudbow allows very accurate retrievals of cloud droplet size and size distribution. The polarized sky radiance distribution as measured e.g. by the SSARA instrument is used for the retrieval of aerosol microphysical properties, i.e. size distribution and refractive index. |
In order to test remote sensing methods for Earth-like exoplanets, observations of the Earthshine, i.e. the light reflected from the Earth's atmosphere and surface towards the Moon and then from the Moon surface back to the Earth, are conducted using e.g. the Very Large Telescope (VLT) in the Atacama desert in Chile. In order to interprete those observations, polarized radiative transfer modelling of the full planet Earth is required (see Emde et al. 2017). |