Search for OClO signatures from Odin limb radiance measurements using DOAS technique
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14-16 April 2003 Limb Workshop, Bremen 1 Search for OClO signatures from Odin limb radiance measurements using DOAS technique P.Krecl, J.Stegman, C.S.Haley, C.E.Sioris, D.P.Murtagh, S.Brohede, E.J.Llewellyn and the Odin Team
description
Search for OClO signatures from Odin limb radiance measurements using DOAS technique. P.Krecl , J.Stegman, C.S.Haley, C.E.Sioris, D.P.Murtagh, S.Brohede, E.J.Llewellyn and the Odin Team. DOAS parameters applied:. O 3 223KVoigt et al NO 2 223KVoigt et al OClO233KKromminga et al - PowerPoint PPT Presentation
Transcript of Search for OClO signatures from Odin limb radiance measurements using DOAS technique
14-16 April 2003 Limb Workshop, Bremen 1
Search for OClO signatures from Odin limb radiance measurements
using DOAS technique
P.Krecl, J.Stegman, C.S.Haley, C.E.Sioris, D.P.Murtagh, S.Brohede,
E.J.Llewellyn and the Odin Team
14-16 April 2003 Limb Workshop, Bremen 2
DOAS parameters applied:
O3 223K Voigt et al
NO2 223K Voigt et alOClO 233K Kromminga et alBrO 223K Fleishman et alRing 250K Chance et alRayleigh Witt et alReference spectrum: 63 co-added spectra TH>55kmSpectral range: 348 – 382 nm, hw1e 0.48 nmBox-car smoothing: 25-pixel widthOrbits: 2175 (Sept 16, 2002) and 2226 (Oct 1, 2002)
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Conclusions and outlook
• Clear signatures of OClO found
• But only qualitative results – ongoing work
• Further optimisiation of DOAS algorithm still needed
• Broad versus narrow spectral region?
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Toward validation of DOAS ozone retrievals in the UV-Vis
region
B. Karlsson, P.Krecl, J.Gumbel, J.Stegman, I.McDade,C.S.Haley
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Approach:
• Retrieved ozone profiles (and sza, ssa) plugged in a FM to obtain limb spectra
• Two FM compared: differences <5%
• Slant column densities in DOAS sense retrieved
• Apparent slant column densities compared
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Summary
• Ozone DOAS retrievals 20-30% lower than the present Flittner product
• Higher discrepancy for high ozone
• No clear correlation with albedo, sza,
• Sensitivity to the short wavelength limit of the fitting range
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Outlook
• Investigate sensitivity to the choice of reference spectrum
• Further optimise the fitting range
• ….whatever more we learn here!
