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Retrievals of Stratospheric Ozone Density Profiles from Odin/OSIRIS Limb-Scatter Measurements. C.S. Haley York University S.V. Petelina University of Saskatchewan and the OSIRIS Team. Method. Step 1: Normalization of limb radiance profiles. with TH i being the i th tangent height,
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Retrievals of Stratospheric Ozone Density Profiles from Odin/OSIRIS Limb-Scatter Measurements C.S. Haley York University S.V. Petelina University of Saskatchewan and the OSIRIS Team
Method Step 1: Normalization of limb radiance profiles with THi being the ith tangent height, THref reference tangent height Reduction of the impact of albedo on limb radiance profiles Step 2: Combination of wavelengths • Employ the Chappuis absorption bands of O3, • and define the Chappuis retrieval vector yC(TH) by
Optimal Estimation xn+1 = x0 + SxKnT[KnSxKnT + S] -1 (y - yn - Kn(x0-xn)) S = Sx - SxKT[KSxKT + S]-1KSx x0: ln of a priori O3 profile xn: ln of nth estimate y: ln of measured Chappuis retrieval vector yn: ln of modelled Chappuis retrieval vector for xn Sx: covariance matrix of a priori S: covariance matrix of measurement y K: Weighting function matrix • Forward model is LIMBTRAN [Griffioen and Oikarinen, 2000] • Pseudo-spherical: SS treated in spherical shell atmosphere • Diffuse radiance source functions calculated in 1-D plane • parallel atmosphere applying the finite differences method. • Variation of SZA and along LOS.
Future Work • Good agreement between OSIRIS, POAM III & SAGE II • Data is now being used in some preliminary assimilation studies and to evaluate other retrieval methods (DOAS, BIN, MOP) • Apparent tangent height registration issues that need to be addressed • Addition of UV wavelengths required to improve upper stratosphere retrievals – in progress
