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Validation of the MIPAS CO 2 volume mixing ratio in the mesosphere and lower thermosphere and comparison with WACCM simulations
Author(s) -
LópezPuertas Manuel,
Funke B.,
JuradoNavarro Á. A.,
GarcíaComas M.,
Gardini A.,
Boone C. D.,
Rezac L.,
Garcia R. R.
Publication year - 2017
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2017jd026805
Subject(s) - thermosphere , atmospheric sounding , atmospheric sciences , atmosphere (unit) , mesosphere , environmental science , climatology , solstice , polar , polar night , northern hemisphere , zonal and meridional , stratosphere , meteorology , geology , ionosphere , geodesy , physics , astronomy , geophysics , latitude
We present the validation of Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) CO 2 daytime concentration in the mesosphere and lower thermosphere by comparing with Atmospheric Chemistry Experiment (ACE) Fourier transform spectrometer and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) data. MIPAS shows a very good agreement with ACE below 100 km with differences of ∼5%. Above 100 km, MIPAS CO 2 is generally lower than ACE with differences growing from ∼5% at 100 km to 20–40% near 110–120 km. Part of this disagreement can be explained by the lack of a nonlocal thermodynamic equilibrium correction in ACE. MIPAS also agrees very well (∼5%) with SABER below 100 km. At 90–105 km, MIPAS is generally smaller than SABER by 10–30% in the polar summers. At 100–120 km, MIPAS and SABER CO 2 agree within ∼10% during equinox but, for solstice, MIPAS is larger by 10–25%, except near the polar summer. Whole Atmosphere Community Climate Model (WACCM) CO 2 shows the major MIPAS features. At 75–100 km, the agreement is very good (∼5%), with maximum differences of ∼10%. At 95–115 km MIPAS CO 2 is larger than WACCM by 20–30% in the winter hemisphere but smaller (20–40%) in the summer. Above 95–100 km WACCM generally overestimates MIPAS CO 2 by about 20–80% except in the polar summer where underestimates it by 20–40%. MIPAS CO 2 favors a large eddy diffusion below 100 km and suggests that the meridional circulation of the lower thermosphere is stronger than in WACCM. The three instruments and WACCM show a clear increase of CO 2 with time, more markedly at 90–100 km.