ON THE ASSESSMENT AND UNCERTAINTY OF ATMOSPHERIC TRACE GAS BURDEN MEASUREMENTS WITH HIGH-RESOLUTION INFRARED SOLAR OCCULTATION SPECTRA FROMSPACE BY THE ATMOS EXPERIMENT

The Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument is a hi gh resolution Fourier transform spectrometer that measures atmospheric composition from low Earth orbit with infrared solar occultation soun ding in the limb geometry. Following an initial flight in 1985, ATMOS participated in the Atmospheric Laboratory for Applications and Scienc e (ATLAS) 1, 2, and 3 Space Shuttle missions in 1992, 1993, and 1994 y ielding a total of 440 occultation measurements over a nine year perio d. The suite of more than thirty atmospheric trace gases profiled incl udes CO2, O-3, N2O, CH4, H2O, NO, NO2, HNO3, HCl, HF, ClONO2, CCl3F, C Cl2F2, CHF2Cl, and N2O5. The analysis method has been revised througho ut the mission years culminating in the 'version 2' data set. The spec troscopic error analysis is described in the context of supporting the precision estimates reported with the profiles; in addition, systemat ic uncertainties assessed from the quality of the spectroscopic databa se are described and tabulated for comparisons with other experiments.