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CAMM model performance assessed during DODO2

CAMM model performance assessed during DODO2. Steph Woodward – climate model dust scheme Glenn Greed – implementation of dust in the CAMM model – Running of operational forecasts for use in DODO2 flight planning Mark Harrison – NAME model forecasts

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CAMM model performance assessed during DODO2

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  1. CAMM model performance assessed during DODO2 Steph Woodward – climate model dust scheme Glenn Greed – implementation of dust in the CAMM model – Running of operational forecasts for use in DODO2 flight planning Mark Harrison – NAME model forecasts Jim Haywood – Analysis of aircraft data Sundar Christopher – Satellite retrievals/validation

  2. Description of the CAMM: • Non-hydrostatic • Two-time level semi-implicit semi-Lagrangian scheme • Charney-Philips staggering in the vertical • Arakawa C grid in the horizontal • Data assimilation (4-D var) satellite, sonde, surface, and data from commercial aircraft

  3. Description of the CAMM: • Domain:- • Resolution: 0.18°x0.18° resolution (~20km) • 38 levels in the vertical • 13 levels in the boundary layer.

  4. Description of the dust scheme: • Dust scheme based on Woodward (2001) • 6 size bins in the range 0.03-30μm radius • Dust emission is based on the scheme by Marticorena and Bergametti (1995) • Dust flux a function of: clay, silt, and sand fraction, vegetative fraction, soil moisture, friction velocity threshold, and surface layer friction velocity. • Convection, turbulent mixing, gravitational settling accounted for • Dry and wet deposition

  5. Description of the dust optical properties: • Mie scattering • Spherical particles • 6-wavebands in the solar spectrum • 9- wavebands in the long-wave • AOD diagnostic developed at 0.55μm

  6. Modifications when moving from climate model: • Soil data set in climate model - Wilson and Henderson-Sellers (1985) at 3.75o replaced by International Geosphere Biosphere Programme (IGBP, Loveland and Belward, 1998) at 1kmx1km.

  7. Additional modifications: • The threshold friction velocities were reduced by 0.15ms-1 and is now defined for all particle sizes spanning 0.06 to 2000μm diameter (rather than 0.06 to 60μm as in W2001). • Horizontal dust flux calculations now include sand particles. The vertical flux is still assumed to consist only of particles between .06 and 60μm. • A correction to the dust uplift code have also been introduced which inhibits emissions of dust from steep slopes.

  8. CASE STUDY – AUG 23rd

  9. The dust forecast from the 21st August

  10. The dust forecast from the 21st August

  11. The dust forecast from the 21st August

  12. The dust forecast from the 21st August Tropical storm Debbie Dust storm within range of BAe146

  13. A t+9 forecast: Tropical storm Debbie Dust storm within range of BAe146

  14. The problems of model validation are shown by the MISR coverage:

  15. Therefore correlative methods of MISR-OMI are developed (Christopher et al):

  16. Comparison of dust event with Dakar AERONET

  17. Flight pattern on the 23rd August 2006

  18. Comparison of the vertical profile from aircraft against the CAMM vertical profiles for two aircraft deep profiles.

  19. MONTHLY MEAN COMPARISONS

  20. Can also look at the monthly means:

  21. Monthly mean comparisons:

  22. AERONET monthly means:

  23. Conclusions: Case study: • The CAMM model shows SKILL up to (and beyond?) 42hours. • The horizontal position and vertical extent of the dust is well represented • The optical depth is reasonably well represented Monthly means: • The OMI/MISR comparisons show a reasonable agreement • AERONET shows a reasonable agreement

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