Dk. Zhou et al., Evidence of non-LTE effects in mesospheric water vapor from spectrally-resolved emissions observed by CIRRIS-1A, GEOPHYS R L, 26(1), 1999, pp. 67-70
Evidence of non-LTE effects in mesospheric water vapor as determined by inf
rared spectral emission measurements taken from the space shuttle is report
ed. A cryogenic Michelson interferometer in the CIRRIS-1A shuttle payload y
ielded high quality atmospheric infrared spectra. These measurements demons
trate the enhanced daytime emissions of H2O (020-->010) which are the resul
t of non-LTE processes and in agreement with non-LTE models. The radiance r
atios of H2O (010-->000) and (020-->010) Q(1) transitions during daytime ar
e compared with non-LTE model calculations to assess the vibration-to-vibra
tion exchange rate between H2O and O-2 in the mesosphere. An exchange rate
of 1.2x10(-12) cm(3) s(-1) is derived.