Open AccessObserved atmospheric collision‐induced absorption in near‐infrared oxygen bands
Author(s) -
Mlawer Eli J.,
Clough Shepard A.,
Brown Patrick D.,
Stephen Thomas M.,
Landry Joseph C.,
Goldman Aaron,
Murcray Frank J.
Publication year - 1998
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/97jd03141
Subject(s) - radiance , radiative transfer , solar zenith angle , absorption (acoustics) , zenith , materials science , atmospheric radiative transfer codes , spectral line , infrared , spectral resolution , transmittance , absorption spectroscopy , absorptance , water vapor , physics , atomic physics , optics , atmospheric sciences , reflectivity , astronomy , meteorology
A recent high‐resolution measurement of surface solar radiance taken under cloud‐free conditions by the Absolute Solar Transmittance Interferometer shows clear indication of continuum absorption associated with the three strongest O 2 a 1 Δ g ← X 3 Σ g − transitions. The differences between these measurements and a calculation by the line‐by‐line radiative transfer model (LBLRTM) were used to determine the properties of these collision‐induced bands and, for two of the bands, led to parameterizations of the spectral behavior of the absorption coefficients. The results indicate that these continuum bands absorb 0.84 W/m 2 at the 71.5° solar zenith angle associated with the observation. For the observed 3000–9965 cm −1 spectrum, with the exception of the spectral range in which this collision‐induced absorption occurs, there is good agreement between the measured and calculated radiance values, with no evidence for discrete absorption by unknown gases.