Bibcode
Bramstedt, K.; García-Muñoz, A.
Bibliographical reference
Journal of Quantitative Spectroscopy and Radiative Transfer, Volume 113, Issue 12, p. 1566-1574.
Advertised on:
8
2012
Citations
3
Refereed citations
2
Description
The present work investigates the Collision Induced Absorption (CIA)
bands of oxygen that occur at 1065 and 1270 nm from solar occultation
data obtained with the space-borne spectrometer SCIAMACHY. The effort is
motivated by the interest in these two strong CIA bands in atmospheric
research and the paucity of data on them under realistic atmospheric
conditions. The observing geometry provides long integration paths and
in turn easily measurable absorption signals. Our analysis method relies
on the accurate separation of the CIA band signature from the rest of
the continuum and structured components over selected spectral
intervals. We show that the shapes of the two CIA bands seem well
described by specific laboratory determinations over a broad range of
tropospheric and low-stratospheric conditions. By analyzing a full month
of solar occultation data we find that the ratio of peak binary cross
sections in air, σ1270nmpeak/σ1065nmpeak, is ∼4 and
seemingly independent of tangent height from 6 to 18 km. We tentatively
estimate the absolute binary cross sections and compare them to existent
measurements. A better characterization of the near-infrared CIA bands
of oxygen should facilitate their implementation in remote sensing
applications in the way it is often done with the CIA bands that occur
in the visible.