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AO 160 – OZVAL V alidation of ENVISAT ozone products through assimilation in the MSDOL model: First results obtained with GOMOS. Authors: B. Théodore and the OZVAL team. Objectives. Data assimilation for ENVISAT stratospheric ozone measurements using the MSDOL model
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AO 160 – OZVAL Validation of ENVISAT ozone products through assimilation in the MSDOL model: First results obtained with GOMOS Authors: B. Théodore and the OZVAL team
Objectives • Data assimilation for ENVISAT stratospheric ozone measurements using the MSDOL model • Daily delivery of ozone profiles over selected stations at synoptic hours • Daily maps of assimilated ozone field at synoptic hours
CTM driven by analysed ECMWF wind fields Resolution: 2.5°x2.5°, 36 pressure levels between 240 to 0.3 hPa (10 to 62 km) 33 chemical species computed, semi-lagrangian transport Sequential assimilation of O3 profiles MSDOL
Read Level2 products from their native format; Select useable data ; Convert concentrations to mixing ratios using ECMWF temperature ; Compute matrix H : each selected point is located on the model grid and the interplation coefficients are computed ; Save these informations in a file (one file per profile). Data pre-processing
Comparison with an ozone sounding at Marambio (64.23°S, 56.72°W)
Comparison with Lidar profiles at Lauder (45.05°S, 169.68°E)
Conclusions • GOMOS profiles exhibit large oscillations • Error bars in GOMOS products are unreliable • Careful data selection allows good assimilation results for ozone
Perspectives • assimilation of GOMOS data over upcoming validation campaigns • Assimilation of GOMOS “line densities” could help dealing with the “strong oscillations” problem