1 / 23

MODIS AEROSOL PRODUCTS: Status and Future Lorraine Remer and Yoram Kaufman And the aerosol team

MODIS AEROSOL PRODUCTS: Status and Future Lorraine Remer and Yoram Kaufman And the aerosol team. MODIS aerosol validation 2000-2002. AERONET sites. ocean. ocean land both. 66% of MODIS aerosol retrievals over ocean fall within expected uncertainty. 71% of MODIS aerosol retrievals

knox-mccarthy
Télécharger la présentation

MODIS AEROSOL PRODUCTS: Status and Future Lorraine Remer and Yoram Kaufman And the aerosol team

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MODIS AEROSOL PRODUCTS: Status and Future Lorraine Remer and Yoram Kaufman And the aerosol team

  2. MODIS aerosol validation 2000-2002 AERONET sites ocean ocean land both 66% of MODIS aerosol retrievals over ocean fall within expected uncertainty 71% of MODIS aerosol retrievals over land fall within expected uncertainty land

  3. MODIS aerosol validation 2000-2002 No filtering out of dust retrievals. 271 co-located points with t > 0.15 from ~500 points for all t. 62% fall with ±0.10 µm

  4. Yoram Kaufman

  5. Yoram Kaufman

  6. Version 4 What’s new?

  7. Version 4 Introduces a highly absorbing model over land. Ichoku et al. (2003)

  8. Over land, For slant view path, we relax dark target criteria. At nadir, r2.1 < 0.25 At edges, r2.1 < 0.40 However, we decrease QA flag to 0.

  9. NEW OLD

  10. Over Ocean: - Changes in cloud mask. Still based on spatial variability, but cleaner application of spatial masking and added absolute threshold of r0.47 < 0.40. - Call backs for heavy dust. r0.47/ r0.66 determines if dust or cloud. - Retrieving heavy dust over glint. Again r0.47/ r0.66 determines if dust

  11. 10 Nov 2001 NEW Heavy dust…. Call back and retrieval over glint OLD However, lots of cirrus in the image Right or wrong? Jury is still out. QA = 0

  12. Applications to aerosol radiative forcing.

  13. Aerosol size: proxy for separating natural from man-made aerosol (aerosol forcing) Red = fine Green = coarse Aerosol size: defines scattering properties that will determine flux backscattered to space (aerosol forcing) Image by Reto Stockli, Earth Observatory

  14. Aerosol radiative forcing (using off line model) t large mostly fine SMOKE! t small mostly coarse SALT! F toa = 10 Wm-2 F sfc= -26 Wm-2 Chou radiation model AERONET/in situ statistics Ichoku et al. 2002

  15. Aerosol Radiative Forcing (MODIS/CERES) Christopher and Zhang (2002) MODIS L3 Sept 2000 AOT 0.55 µm AOT 0.55 µm Requirement: No clouds in CERES footprint. CERES analysis may miss SAFARI smoke over adjacent ocean - spatial resolution (30 km) - visible channel cloud mask Results are biased to very clear sky SWARF Wm-2 MODIS’s 500 m resolution and spatial variability cloud mask, will not miss important heavy aerosol events nor aerosols in cloud “holes”.

  16. AOT Flux Deriving Flux from satellite more accurate than deriving AOT Aerosol radiative forcing (directly from MODIS)

  17. Success! 1. More accurate t retrievals overocean(cut error in half) 2.First attemptat operational t retrievals overland 3. Both land/ocean t retrievals aremeeting expectations 4. Retrieval ofquantitative sizeinformation over ocean 5. Separation of aerosol intonatural and man-made components 6. Improved measurement-based estimates ofradiative forcing. 3 options: off-line model, CERES, directly from MODIS 7. Bettercloud discriminationandretrievals closer to clouds. (MODIS: 500 m resolution; AVHRR: 4 km; TOMS:17 km)

  18. The Future Yoram has resigned from the MODIS science team. Lorraine will be writing the maintenance and refinement proposal, with the hope of becoming a team member. Didier will continue as a non-funded foreign team member.

  19. Proposed: 1. Continue to examine aerosol models and make changes as needed. SAFARI

  20. 2. Introduce empirical phase functions in ocean algorithm to better derive size in dust regimes.

  21. 3. Re-evaluate Land Algorithm from the beginning. - cloud masking over land - Alternative: Path Radiance method NO assumptions of rsfc0.66 = 0.5* r2.1 rsfc0.47 = 0.25* r2.1 - Alternative: True inversion (like ocean algorithm) input: r 0.47, r0.66 and r2.1 output: t0.55, rsfc2.1 , h

  22. 4. New data formats - A level 2 gridded product An atmospheric product doesn’t need to be consistently registered to the ground on subsequent days, but a land product does… Aerosol radiative forcing has characteristics of both atmosphere and land. - A MODIS aerosol product derived inherently within the CERES footprint. To be processed at Langley using the 1 km MODIS L1b product already there. Possibility of including a MISR-MODIS inversion in this joint product.

  23. We will submit 5 proposals on April 15 - Maintenance/Refinement (PI-Remer, Kaufman, Tanré) - Observationally based aerosol direct radiative forcing. (PI-Kaufman, Remer, Chin, Dubovik) - Remote sensing of aerosol absorption and direct radiative forcing (PI-Martins) - Applications of fire radiative energy (PI- Ichoku, Kaufman, Hao) - Applications of aerosol product for operational Air Quality forecasting (PI-Chu, Remer, Sykzman)

More Related