1. 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

2. Step 1: Normalization of limb radiance profiles with TH i being the ith tangent height, TH ref reference tangent height Reduction of the impact of albedo on limb radiance profiles Step 2: Combination of wavelengths Employ the Chappuis absorption bands of O 3, and define the Chappuis retrieval vector y C (TH) by Method

3. OS Limb Scan

4. x n+1 = x 0 + S x K n T [K n S x K n T + S  ] -1 (y - y n - K n (x 0 -x n )) S = S x - S x K T [KS x K T + S  ] -1 KS x x 0 : ln of a priori O 3 profile x n : ln of nth estimate y: ln of measured Chappuis retrieval vector y n : ln of modelled Chappuis retrieval vector for x n S x : covariance matrix of a priori S  : covariance matrix of measurement y K: Weighting function matrix Optimal Estimation 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.

5. OS and TOMS ozone column daily maps 25 February 2002

6. OS – POAM Comparisons OS – POAM III comparisons Coincidence criteria: 4h UT 5  latitude 10  longitude SZA  88  Month/Year Hemisphere Lat. range # coincidences November 01SH63  -57  76 December 01SH60  -70  122 January 02SH57  -67  119 February 02SH64  -74  66 March 02NH61  -71  35 April 02NH56  -70  145 May 02NH53  -63  97 June 02NH50  -58  108 July 02NH51  -61  140 August 02NH57  -67  101 September 02NH62  -72  12 October 02SH70  - 82  131

7. OS – POAM Comparisons

9. OS – POAM Comparisons OS – POAM Comparisons November 2001

10. OS – POAM Comparisons OS – POAM Comparisons February 2002

11. OS – POAM Comparisons OS – POAM Comparisons December 2001

12. OS – POAM Comparisons OS – POAM Comparisons June 2002

13. OS – SAGE II comparisons Coincidence criteria: 10  latitude Same day of observations Month, Year HemisphereLat.range #OS / #SAGE November 01NH,SH0  -10  N34/29 10  -0  S31/28 20  -10  S49/30 30  -20  S37/18 December 01SH55  -45  S 38/40 January 02SH20  -10  S29/29 30  -20  S74/33 40  -30  S48/38 50  -40  S42/44 February 02NH,SH0  -10  N14/25 10  -0  S13/20 60  -50  S46/37 70  -60  S49/64 March 02NH,SN10  -20  N60/22 0  -10  N39/19 20  -10  S31/40 30  -20  S9/14 April 02NH0  -15  N13/15 May 02NH0  -10  N54/29 10  -20  N11/21 50  -60  N87/48 60  -70  N68/78 June 02NH10  -20  N 20/10 20  -30  N23/34 30  -40  N29/40 40  -50  N34/31 July 02NH50  -60  N 78/66 60  -70  N118/146

14. OS-SAGE Comparisons OS-SAGE Comparisons November 2001

15. OS-SAGE Comparisons OS-SAGE Comparisons February 2002

16. OS-SAGE Comparisons OS-SAGE Comparisons June 2002

17. OS-SAGE Comparisons OS-SAGE Comparisons July 2002

18. OSIRIS-OZONE SONDES COMPARISONS Coincidence criteria: 5  latitude, 10  longitude, same day of observations Month/Year Hemisphere # comparisons November 01SH11 December 01SH12 January 02SH10 February 02SH12 March 02SH,NH36 April 02NH26 May 02NH20 June 02NH15 July 02NH20 August 02NH25 September 02NH, SH19

19. OS-sonde Comparisons

21. Ozone hole split in September 2002

26. 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