Abstract

The Stratospheric Aerosol and Gas Experiment II (SAGE II) instrument is a multi-channel sun photometer designed to measure aerosol and molecular scattering, and absorption due to ozone, nitrogen dioxide and water vapor from space. SAGE II is mounted on the Earth Radiation Budget Satellite (ERBS) which is scheduled to be deployed by the space shuttle in the early part of October, 1984. Ozone and nitrogen dioxide have been measured previously with the SAGE¹ satellite system. The radiative transfer calculations for these two gases are relatively simple because of the lack of line structure in these bands and the insensitivity of the absorption cross sections to pressure and temperature. The .94 μm water vapor band covered by SAGE II, however, requires time consuming line-by-line radiative transfer calculations to model. Line by line calculations are impractical for the reduction of large amounts of limb occultation satellite data and tradeoffs between accuracy and speed must be considered². This paper discusses the radiative transfer code selected for use in the water vapor retrieval algorithm and presents several sensitivity studies conducted with this code.

© 1985 Optical Society of America