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Dust: Data and Sources

Dust: Data and Sources. Dr Richard Washington University of Oxford Dr Martin Todd University College London. Prof Andrew Goudie University of Oxford Dr Mike Bithell University of Cambridge. Outline. Dust Data Surface based synops (from GCOS, 117 stations, 3hrly 1980-2000)

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Dust: Data and Sources

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  1. Dust: Data and Sources Dr Richard Washington University of Oxford Dr Martin Todd University College London Prof Andrew Goudie University of Oxford Dr Mike Bithell University of Cambridge

  2. Outline • Dust Data • Surface based synops (from GCOS, 117 stations, 3hrly 1980-2000) • Surface based synops (from local Met Agencies) • TOMS AI data • IDDI • Shuttle Photographs, NOAA images etc • Climate Data and Trajectory modelling • Reanalysis Data (NCEP and ERA-15) 3D winds • 25 point forward trajectory clusters • every 6 hours for 10days, 1979-1998 • Determine regional transport corridors • Re-circulation • Interannual variability

  3. Nr Missing Months 1980-2000

  4. Nr Missing Months 1980-2000

  5. Nr Missing Months 1980-2000

  6. Nr Missing Months 1980-2000

  7. GCOS Data Compared with locally Obtained Data

  8. In Salah visibility 80-00

  9. Outline • Dust Data • Surface based synops (from GCOS, 117 stations) • Surface based synops (from local Met Agencies) Niger, Chad, Algeria, Mali, Mari • TOMS AI data • IDDI • Shuttle Photographs, NOAA images etc • Climate Data and Trajectory modelling • Reanalysis Data (NCEP and ERA-15) 3D winds • 25 point forward trajectory clusters • every 6 hours for 10days, 1979-1998 • Determine regional transport corridors • Re-circulation

  10. Niger visibility 70-00

  11. N’Djamena, Chad: Haze Vs Obs Rainfall By season

  12. Bilma, Niger: sandstorms Vs TOMS by season

  13. North African Surface Dust storms Correlation TOMS 1980-2000

  14. Bilma surface visibility Vs TOMS (march 1980-2000)

  15. Outline • Dust Data • Surface based synops (from GCOS, 117 stations) • Surface based synops (from local Met Agencies) Niger, Chad, Algeria, Mali, Mari • TOMS AI data • IDDI • Shuttle Photographs, NOAA images etc • Climate Data and Trajectory modelling • Reanalysis Data (NCEP and ERA-15) 3D winds • 25 point forward trajectory clusters • every 6 hours for 10days, 1979-1998 • Determine regional transport corridors • Re-circulation

  16. REOF2 of TOMS AI monthly anomalies for the period 1980-05/93 and 1997-2000

  17. REOF3 of TOMS AI monthly anomalies for the period 1980-05/93 and 1997-2000

  18. REOF5 of TOMS AI monthly anomalies for the period 1980-05/93 and 1997-2000

  19. REOF6 of TOMS AI monthly anomalies for the period 1980-05/93 and 1997-2000

  20. REOF7 of TOMS AI monthly anomalies for the period 1980-05/93 and 1997-2000

  21. REOF8 of TOMS AI monthly anomalies for the period 1980-05/93 and 1997-2000

  22. Apr Potential Sand Flux overlay TOMS q = 2.61 U3*pg –1 (1-U*/U*)(1+U*/U*)2

  23. SahelTOMS (white contours), potential sand flux (black contours), with DEM (colour). LTM for JFM 80-00.

  24. Central AsiaTOMS (white contours), potential sand flux (black contours), with DEM (colour). Long term mean for 80-00.

  25. Correlation of monthly visibility anomalies at Nouakchott (Mauritania) with global NCEP derived potential sand flux for 1980-2000

  26. Correlation of monthly visibility anomalies at Bobo-Dioulasso (Burkina Faso) with global NCEP derived potential sand flux for 1980-2000

  27. Outline • Dust Data • Surface based synops (from GCOS, 117 stations) • Surface based synops (from local Met Agencies) Niger, Chad, Algeria, Mali, Mari • TOMS AI data • IDDI • Shuttle Photographs, NOAA images etc • Climate Data and Trajectory modelling • Reanalysis Data (NCEP and ERA-15) 3D winds • 25 point forward trajectory clusters • every 6 hours for 10days, 1979-1998 • Determine regional transport corridors • Re-circulation

  28. Djouf region Bodele

  29. Parcel trajectory climatology May (1979-98) Bodele depression (17.5N, 17E) 54% of trajectories cross the 15W meridian 27% of trajectories remain over N. Africa 21% of trajectories remain over Sahara (> 15N)

  30. Parcel trajectory climatology June (1979-98) Bodele depression (17.5N, 17E) 79% of trajectories cross the 15W meridian 13% of trajectories remain over N Africa 9% of trajectories remain over Sahara (> 15N)

  31. Parcel trajectory climatology Dec (1979-98) Bodele depression (17.5N, 17E) 66% of trajectories cross the 15W meridian 23% of trajectories remain over N. Africa 6% of trajectories remain over Sahara (> 15N)

  32. Dust Recycling potential May July June Dec

  33. Parcel trajectory climatology May (1979-98) Bodele depression (17.5N, 17E) Mean 0-15N

  34. Parcel trajectory climatology Dec (1979-98) Bodele depression (17.5N, 17E) Mean 0-15N

  35. TOMS AI over Bodele region (15-17N, 16-18E) mean May 1991 May 1989

  36. May 1991 Height (hPa) Lat. Long.

  37. May 1989 Height (hPa) Lat. Long.

  38. Djouf region

  39. TOMS AI over Djouf region (17.5-22.5N, 2.5-7.5W)

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