Combined modelling of shortwave and thermal radiation for one-imensional SVATs

摘要

Expressions for the upwelling and downwelling fluxes ofoptical and thermal radiation between soil, vegetation and the sky are derived, undercertain simple assumptions. These are that interception of radiation by the vegetation isa purely geometric effect, while scattering is isotropic, with a strength given by asingle-scattering albedo in the optical part of the spectrum, and by Kirchhoff's Law inthe thermal. The soil is assumed to be a lambertian reflector, also scattering accordingto an albedo and Kirchhoff's Law. The model, called RM, conserves energy exactly. As partof a SVAT, it is driven by measured insolation instead of radiation, with little increasein computational cost and number of parameters.