GOMETRAN - A RADIATIVE-TRANSFER MODEL FOR THE SATELLITE PROJECT GOME,THE PLANE-PARALLEL VERSION

The Global Ozone Monitoring Experiment (GOME) is a new, nadir-viewing instrument on the European Space Agency satellite ERS 2 which was laun ched in April 1995. With diode-array detector technology, spectra of t he upwelling radiance are measured simultaneously at thousands of wave lengths in the UV, visible, and near-IR regions. Inversion of these me asurements by appropriate algorithms allows the retrieval of the distr ibution of gaseous and particulate constituents, which modulate the ra diance by absorption, emission, or scattering processes. Such a retrie val algorithm requires an accurate radiative transfer model to describ e the propagation of light through the atmosphere. The model GOMETRAN has been specially designed to fulfill the needs of GOME, but it appli es generally to other downward looking space instrumentation in the UV , visible, or near-IR. In this paper the model is described in the pla ne-parallel version, and the optimization of computational parameters and comparisons with other radiative transfer models is presented.