Intercomparisons of trace gases profiles from the Odin/SMR and Aura/MLS limb sounders
Journal article, 2006
This paper presents the intercomparison of O(3), HNO(3), ClO, N(2)O and CO profiles measured by the two spaceborne microwave instruments MLS ( Microwave Limb Sounder) and SMR ( Submillimetre Radiometer) on board the Aura and Odin satellites, respectively. We compared version 1.5 level 2 data from MLS with level 2 data produced by the French data processor version 222 and 225 and by the Swedish data processor version 2.0 for several days in September 2004 and in March 2005. For the five gases studied, an overall good agreement is found between both instruments. Most of the observed discrepancies between SMR and MLS are consistent with results from other intercomparison studies involving MLS or SMR. O(3) profiles retrieved from the SMR 501.8 GHz band are noisier than MLS profiles but mean biases between both instruments do not exceed 10%. SMR HNO(3) profiles are biased low relative to MLS's by similar to 30% above the profile peak. In the lower stratosphere, MLS ClO profiles are biased low by up to 0.3 ppbv relative to coincident SMR profiles, except in the Southern Hemisphere polar vortex in the presence of chlorine activation. N(2)O profiles from both instruments are in very good agreement with mean biases not exceeding 15%. Finally, the intercomparison between SMR and MLS CO profiles has shown a good agreement from the middle stratosphere to the middle mesosphere in spite of strong oscillations in the MLS profiles. In the upper mesosphere, MLS CO concentrations are biased high relative to SMR while negative values in the MLS retrievals are responsible for a negative bias in the tropics around 30 hPa.
SMR
MLS
Odin
Aura
Author
B. Barret
Centre national de la recherche scientifique (CNRS)
P. Ricaud
Centre national de la recherche scientifique (CNRS)
M. Santee
Jet Propulsion Laboratory, California Institute of Technology
J.-L. Attie
Centre national de la recherche scientifique (CNRS)
Joachim Urban
Chalmers, Department of Radio and Space Science, Global Environmental Measurements
E. Le Flochmoën
Centre national de la recherche scientifique (CNRS)
G. Berthet
Donal Murtagh
Chalmers, Department of Radio and Space Science, Global Environmental Measurements
Patrick Eriksson
Chalmers, Department of Radio and Space Science, Global Environmental Measurements
Ashley Jones
Chalmers, Department of Radio and Space Science, Global Environmental Measurements
J. De La Noë
Laboratoire d'Astrophysique de Bordeaux
E. Dupuy
Laboratoire d'Astrophysique de Bordeaux
University of Saskatchewan
L. Froidevaux
Jet Propulsion Laboratory, California Institute of Technology
N.J. Livesey
Jet Propulsion Laboratory, California Institute of Technology
J.W. Waters
Jet Propulsion Laboratory, California Institute of Technology
M.J. Filipiak
University of Edinburgh
Journal of Geophysical Research
01480227 (ISSN) 21562202 (eISSN)
Vol. 111 D21 D21302Subject Categories
Meteorology and Atmospheric Sciences
DOI
10.1029/2006JD007305