Overview and Summary of Results and Significant Findings from the CIRRIS-1A Experiment

Abstract

The cryogenic infrared radiance instrumentation for shuttle (CIRRIS) experiment was own onboard STS-39 from 29 April to 1 May 1991. A comprehensive set of spectral and spatial infrared data of atmospheric and Earth terrain data was collected by an interferometer and radiometer. The mission occurred during a major geomagnetic storm (K p ->5), and as a result, a substantial amount of spectral data on bright auroral backgrounds were collected in the midnight sector of the auroral oval. The coincidental timing of the CIRRIS mission, only a few weeks before the eruption of Mount Pinatubo (June 1991), substantially increased the value of the stratospheric data from CIRRIS, which now serves as a clean atmosphere baseline against which various post-Pinatubo observations can be compared to assess the short-and long-term effects of a major volcanic eruption on the stratosphere. In addition, there were a number of unexpected and important scienti c discoveries that resulted from analysis of the CIRRIS high-resolution Earthlimb emission spectra including the identi cation of an important new class of non-local thermodynamic equilibrium emissions resulting from highly rotationally excited diatomic species (OH, NO and NO + ) in the mesosphere and thermosphere. These nonthermal rotational emissions were observed for both day and nighttime conditionsand were not included in or predicted by existing atmosphericmodels before the CIRRIS ight. A brief overview of the instrumentation and data collection methods is presented. A general review of the CIRRIS data and a summary of the most signi cant ndings previously reported by various groups are also presented. IntroductionScienti c Objectives T HIS paper summarizes the results and major ndings from the cryogenic infrared radiance instrumentation for shuttle (CIRRIS-1A) experiment that was own onboard STS-39 between 29 April and 1 May 1991. This study consisted of a global infrared remote sensing survey that sampled the atmosphere from the nadir up through the Earthlimb to shuttle altitudes of 260 km in the 2.5-25 ¹m wavelength region. The primary objective of this experiment was to obtain simultaneous spectral and spatial measurements of atmospheric emissions for altitudes between 0 and 150 km. Atmospheric species of interest included water, hydroxyl, nitric oxide, ozone, and carbon dioxide during day and night under various levels of geomagnetic activity. Observations covered a range of latitudes from approximately ¡68 to C68 deg during moderate to active geomagnetic activity (K p D 3-7) and also when bright aurora were observed. Data were collected from numerous strong atmospheric emitters, such as OH at 2.7 ¹m and CO 2 at 4.3 and 15 ¹m, NO at 5.3 ¹m, O 3 at 9.6 ¹m, and H 2 O at 6.3 ¹m and in the long wavelength infrared (LWIR) region. Many other trace species were also measured, such as CFC-11 and CFC-12, HNO 3 , CH 4 , and CO. Data were taken simultaneously by three infrared (IR) instruments: 1) an interferometer with an eight position lter wheel, 2) a lter radiometer with 7 wide...

Contribution of chemical processes to infrared emissions from nitric oxide in the thermosphere

“…Daytime measurements of the emission were collected in the Northern Hemisphere with the solar zenith angle varying between 60 and 90° for low (15°) to middle (45°) latitudes. The 2.7 µm overtone emission from NO was measured in the 2.5–3.4 µm band pass of the radiometer, which also recorded emission from CO 2 , H 2 O, and OH near 2.7 µm [ Wise et al ., ]. However, these emissions are not detectable above 100 km and do not interfere with the measurement of the emission from nitric oxide.…”

Vibrationally excited ozone in the middle atmosphere

“…But to the authors' knowledge, there are no further emitters in addition to O 3 , CO, CO 2 , and H 2 O in the 60-70 km regime that might significantly increase the 4:8 mm radiances (see, e.g. the measurements of the CIRRIS-1A experiment; Wise et al, 2001).…”

Infrared Sky Surveys

“…A second, more capable sensor (CIRRIS-1A) replaced CIRRIS 1 and was flown on the STS-39 Shuttle Discovery mission on 28 April 1991 into a 260 km altitude orbit. Wise et al (2001) gave a comprehensive overview of the CIRRIS 1A experiment as well as a detailed summary of the scientific results from all of the CIRRIS 1A articles published prior to 2001 while Wheeler et al (1992) and Dean et al (1994) present the CIRRIS 1A well resolved spectra and good quality radiometric observations of the Shuttle induced optical contamination.…”