Abstract

The High resolution Interferometer Sounder (HIS), is a Michelson interferometer which observes the spectrum of infrared radiance (3.5 - 18 μm) with a spectral resolution ( λ/Δλ) better than 2000/1. During 1994, the HIS flew aboard the NASA ER-2 during a series of flights between Christchurch New Zealand and the Antarctic ice shelf as part of the Airborne Southern Hemisphere Ozone Experiment (ASHOE). The intent of the HIS was to retrieve atmospheric profiles of temperature, water vapor, and ozone beneath the Aircraft (20 Km) flight level. The profile retrievals are needed to validate global Numerical Weather Prediction (NWP) models used to prescribe the thermodynamic and dynamic variables used to estimate the chemical interactions and transports of the molecules responsible for Ozone depletion (i.e., the "Ozone Hole"). In order to accomplish this objective, a procedure for profile retrieval had to be developed which was both accurate and independent of the contemporary meteorological observations which influence NWP models; needless to say a model forecast could not be used as an initial guess for the retrieval process. Because of the extensive cloudiness over the Southern Oceans, the method had to be able to provide accurate retrievals above clouds, regardless of their altitude or their opacity. This paper describes the method developed for this application and provides results from the spectral radiance data obtained during the ASHOE to demonstrate their accuracy.

© 1995 Optical Society of America