Inverse Modeling of Radiative Transfer by Two-Stream Approximation using the Luus-Jaakola Method.

Abstract

The simulation of terrestrial ecosystem processes, using numerical biosphere-atmosphere models that can be directly coupled to the Atmospheric General Circulation Models (AGCM) and Regional Atmospheric Models, assists to a more accurate diagnosis and prognosis of climate and weather. These models describe the interaction processes with the atmosphere and the transient changes that occur in vegetation composition and structure. The solar radiation module of the biosphere-atmosphere models is relevant when considering dynamic models due to being the main mechanism of energy contribution to an ecosystem. The distribution of solar radiation inside the vegetation canopy controls the entire dynamics of plant growth through the portion absorbed by photosynthesis. This also influences the assimilation of water and nutrients in the soil by the mechanisms of heat and mass exchange. In this work the two-stream radiative transfer model, [2,5] was adopted. The Shooting Method was used to solve the Ordinary Differential Equations (ODE) system in the Scilab mathematical modeling environment, as well as the Luus-Jaakola method, [6], to obtain the necessary parameters to solve the direct problem.