Cryogenic Infrared Radiance Instrumentation for Shuttle (CIRRIS 1A) Earth limb spectral measurements, calibration, and atmospheric O₃, HNO₃, CFC‐12, and CFC‐11 profile retrieval

Abstract

During the Space Transportation System 39 (STS 39) flight of April 28 to May 6, 1991, the Cryogenic Infrared Radiance Instrumentation for Shuttle (CIRRIS 1A) measured spectral and spatial (“Earth limb scan”) distributions of the atmospheric infrared (IR) emissions using a Michelson interferometer. The IR spectral radiant emissions from the greenhouse gases were collected at a shuttle altitude of 260 km in the 9–13 μm atmosphere infrared window. Before and after the flight, the response of CIRRIS 1A to the IR spectral emission sources was calibrated using absolute and spectral source types. The Fast Atmospheric Signature Code 3, which used the HITRAN92 database and predetermined temperature‐pressure profiles from the National Meteorological Center, was used in an onion‐peeling routine to retrieve gas concentrations from absolutely calibrated spectral data (moderate resolution ∼1.0 cm −1 ). Vertical profiles of O 3 , HNO 3 , CFC‐12, and CFC‐11 are presented. An error analysis is presented to show the quality of the measured spectral data and the accuracy of these retrieval results. The concentrations of CFC‐11 (3.0×10 −4 ppmv) and CFC‐12 (4.9×10 −4 ppmv) in the tropopause region are consistent with a global flux increment rate of about 5% yr −1 . The observed concentrations of HNO 3 are consistent with previous reports for a relatively clean stratosphere.