G. Zaragoza et al., Global distribution of CO2 in the upper mesosphere as derived from UARS/ISAMS measurements, J GEO RES-A, 105(D15), 2000, pp. 19829-19839
The latitudinal and seasonal variations of the CO2 concentration between 70
and 100 km are investigated using the 4.6 mu m daytime measurements made b
y the Improved Stratospheric and Mesospheric Sounder (ISAMS) on the Upper A
tmospheric Research Satellite (UARS). The analysis uses a detailed nonlocal
thermodynamic equilibrium model of the CO2 states emitting in the 4.3 mu m
spectral region and the GENLN2 line-by-line radiance code to update an ear
lier study by Lopex-Puertas et al., [1998b]. The differences in the CO2 vol
ume mixing ratio between the equator and the illuminated pole in the upper
mesosphere are shown to be smaller than the detection limit established by
the uncertainties in the data (approximately 10% at 85 km, 14% at 90 km, 23
% at 95 km, and 28% at 100 km).