The Atmospheric Trace Molecule Spectroscopy (ATMOS) Experiment: Deployment on the ATLAS space shuttle missions

Abstract

determined by a combination of factors: rapid increase in opacity through the troposphere, aerosols and cloud tops obscuring the sun, lack of accuracy in assigning tangent heights and pressures to individual spectra, and the difficulty in retrieving stratospheric constituent volume mixing ratios (vmrs) below their peak concentrations. Issues limiting the lower altitude range will be addressed in future analyses. The data processing and inversion methods employed with the ATMOS data follow those described by Norton and Rinsland [1991]. As some changes have been incorporated to enhance routine data processing and to distinguish between this current dataset and previous published analyses, the ATMOS data utilized in the papers in this issue have been ascribed to 'Version 2'. In brief, after transformation of the interferograms to power spectra, an average exoatmospheric spectrum is formed for each occultation against which ratios are made with successive atmospheric spectra. The resulting atmospheric transmission spectra are essentially free of solar and instrumental spectral features. The inversion of these transmission spectra follows a general sequence: assignment of a first-guess tangent height based on spacecraft ephemeris data, refinement of the tangent height (or more correctly, tangent pressure) from spectral fitting to the observed CO2 absorption bands [Abrams et al., 1996], and retrieval of atmospheric temperature-pressure profiles [Stiller et al., 1995], followed by a final tangent pressure assignment. Retrievals of vmr profiles for individual species use spectral intervals that are chosen based on the shape and strength of target gas absorption, the insensitivity of these features to errors in temperature, and their relative freedom from interfering absorption from other constituents [e.g., Gunson 2333

Ozone absorption around 10 μm

“…[8] We have checked the new line listing using atmospheric spectra recorded by the ATMOS instrument [Gunson et al, 1996, and references therein]. The modeling of the atmospheric spectra was performed using the ORM (Optimized Retrieval Model) code [Ridolfi et al, 2000] developed for a near real time level 2 analysis of the MIPAS spectra.…”

Validation of POAM III ozone: Comparisons with ozonesonde and satellite data

“…Bruhl et al [1996] showed agreement between HALOE and correlative measurements that was typically within 5% between 1 and 30 mbar (from $25 to 50 km). Few correlative measurements were available at higher altitudes, but Bruhl et al [1996] showed that HALOE O 3 was generally 20-30% lower than version 2.0 data from the Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment [Gunson et al, 1996;Abrams et al, 1996] near 60 km. We have repeated comparisons between HALOE and ATMOS for the most recent versions of the two data sets (19 and 3.0, respectively, not shown), and still find a bias between them near 60 km, but it is at the 10% level (HALOE < ATMOS).…”

MIPAS: an instrument for atmospheric and climate research

“…Although general databases such as HITRAN (Rothman et al, 2005) or GEISA (Jacquinet-Husson et al, 2005) existed it was decided at the beginning of the development of the MI-PAS data processing software to generate a dedicated spectroscopic database for MIPAS, as was done for the ATMOS experiment (Gunson et al, 1996), in order to be able to implement the best spectral parameters in the shortest possible time and also to meet the specific needs of MIPAS. The first version "mipas pf2.0" was based on both the 1996 version of HITRAN and on new laboratory spectroscopic data and new calculations (Flaud et al, 2003a;Flaud et al, 2003b).…”