Improved Jacobian formulation for a unified microwave radiative transfer model: Validation and numerical results

A unified microwave radiative transfer (UMRT) model is developed for rapid, stable, and accurate level-centric calculation of the thermal radiation emitted from any geophysical media comprised of planar multilayer of either densely or loosely distributed, moderately sized spherical scatterers, and also rapid calculation of the Jacobian between the observed brightness temperatures with respect to any relevant radiative parameter, such as scattering and absorption coefficients, medium temperature and temperature lapse rate, and others. UMRT includes both the surface Fresnel reflection and transmission and the internal volumetric reflection and transmission accounting for a planar multilayer strcuture with refracting layers. This paper focuses on developping the general radiative transfer solution under the UMRT multilayer framework and the formulation of associated Jacobian procedure. Details of formulation and validation of the UMRT-Jacobian and comparison between the upwelling radiations obtained from the UMRT model with field measurements are presented here.