1 / 24

J. Livingston (1) , O. Torres (2) , P. Russell (3) , J. Redemann (4) , R. Johnson (3) ,

Comparison of airborne sunphotometer and OMI retrievals of aerosol optical depth during MILAGRO/INTEX-B 2006. J. Livingston (1) , O. Torres (2) , P. Russell (3) , J. Redemann (4) , R. Johnson (3) , R. Bergstrom (4) , Qin Zhang (4) , B. Veihelmann (5) , R. Braak (5) , A. Smirnov (2) ,

tacita
Télécharger la présentation

J. Livingston (1) , O. Torres (2) , P. Russell (3) , J. Redemann (4) , R. Johnson (3) ,

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. Comparison of airborne sunphotometer andOMI retrievals of aerosol optical depth during MILAGRO/INTEX-B 2006 J. Livingston(1),O. Torres(2), P. Russell(3), J. Redemann(4), R. Johnson(3), R. Bergstrom(4), Qin Zhang(4), B. Veihelmann(5), R. Braak(5), A. Smirnov(2), B. Holben(6), L. Remer(6), K. S. Schmidt(7), O. Coddington(7), P. Pilewskie(7) (1) SRI International, Menlo Park, CA, USA (2) University of Maryland, Baltimore County (UMBC)/NASA Goddard, Greenbelt, MD, USA (3) NASA Ames Research Center, Moffett Field, CA, USA (4) Bay Area Environmental Research Institute (BAERI), Sonoma, CA, USA (5) Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands (6) NASA Goddard Space Flight Center, Greenbelt, MD, USA (7) Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA http://geo.arc.nasa.gov/sgg/INTEX-B/index.html email: John.M.Livingston@nasa.gov 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  2. Jetstream 31 (J31) instrument payload and flight overview for MILAGRO/INTEX-B 2006 • Airborne, satellite, and ground-based AOD comparisons • AATS-14, OMI (UV and MW retrievals), & MODIS over water (3 cases) -10 March (Aqua, Aura) -03 March (Aqua, Aura) (no coincident MODIS retrieval due to sun glint) -17 March (Aqua, Aura) • AATS-14, OMI, & AERONET over Mexico City (1 case) -19 March (Aura) • Summary/Conclusions Outline 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  3. AATS-14Ames Airborne Tracking Sunphotometer SSFRSolar Spectral Flux Radiometer CARCloud Absorption Radiometer POSPosition & Orientation System RSPResearch Scanning Polarimeter NavMetMet Sensors & Nav/Met Data System Jetstream 31 in MILAGRO/INTEX-B: Instrument Locations 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  4. NASA Ames Airborne Tracking Sunphotometer: AATS-14 • 1. Measures direct solar beam transmission: • 353.5 380.0 449.0 499.4 525.0 • 605.7 675.1 778.4 864.5 939.7 • 1019.1 1241.3 1557.8 2139.0 nm • Yields: • aerosol optical depth & columnar water vapor (ozone under certain conditions) • aerosol extinction & water vapor (ozone) concentration when aircraft flies profiles • Size: • Telescope dome 8" OD (hemisphere) atop 5" H pedestal. (Total H: 9" above A/C skin), Inside A/C: 12" D x 18" H cylinder. • Weight: • 131.6 lbs 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  5. Low altitude horizontal transect at time of satellite overpass for satellite sensor validation J31 flight patterns:Coordinated satellite, in-situ and radiative missions OMI/Aura CALIPSO CloudSat GLORY POLDER/Parasol MODIS/Aqua MISR, MODIS/Terra B200 DC-8 C-130 J31 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  6. Four J31 flight tracks coincident with OMI overpasses 3 Mar 17 Mar 10 Mar 19 Mar 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  7. True Color Image (Aqua), 10 March, 19:55-20:00 UT OMI 13x24km2 MODIS 10x10 km2 J31 low altitude transect J31 flight track color coded by altitude Aura/OMI overpass ~15 minutes after Aqua at 20:13 UT AOD Comparisons, OMI - MODIS - AATS INTEX-B/MILAGRO, 2006 MODIS 19:40-20:01 UT 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  8. AOD Comparisons, OMI - MODIS - AATS INTEX-B/MILAGRO, 10 March 2006 OMI UV OMI MW MODIS J31 low altitude transect 19:40-20:01 UT J31 low altitude transect 19:40-20:01 UT 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  9. AOD Comparisons, OMI - MODIS - AATS INTEX-B/MILAGRO, 10 March 2006 MODIS % cloud 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  10. 10 March 2006 (over water) AATS-14 J31/AATS measurements AOD extrema along transect 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  11. 10 March 2006 (over water) AATS-14 MODIS c005 AOD extrema along transect 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  12. 10 March 2006 (over water) OMI MW c002 OMI UV c002 AATS-14 MODIS c005 AOD extrema along transect OMI MW & near-UV AOD c002 retrievals significantly exceed MODIS and AATS values. 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  13. 10 March 2006 (over water) Likely cloud contaminated OMI MW c003 AATS-14 MODIS c005 AOD extrema along transect OMI UV c003 OMI near-UV AOD c003 retrievals are much lower than c002 retrievals and yield a non-absorbing aerosol. 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  14. Aqua MODIS 03 March 2006 19:50-19:55 UT True Color Image Cloud Mask J31 low altitude transect 18:50-19:02 UT 19:23- 19:29 UT 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  15. Aqua MODIS 17 March 2006 20:00-20:05 UT True Color Image Fraction of Cloud J31 low altitude transect 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  16. 03 March 2006 (over water) 17 March 2006 (over water) Aqua overpass: 20.07 UT Aura overpass: 20.12 UT Aura overpass: 20.32 UT OMI MW c002 OMI MW c002 OMI UVc002 OMI UVc002 no MODIS AOD retrievals coincident with J31/AATS due to sun glint MODIS c005 AATS-14 AATS-14 OMI MW c003 OMI MW c003 MODIS c005 OMI UV c003 OMI UVc003 AATS-14 AATS-14 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  17. Photo from DC-8 over Mexico City, 19 Mar 2006 Courtesy of Cam McNaughton (Univ. of Hawaii) 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  18. 19 March 2006 J31 flight to Mexico City OMI grid cells AERONET sites at T0, T1 & T2 (rendezvous with C-130, B200, DC-8) 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  19. 19 March 2006 (over land) Aura overpass: 20.11 UT J31 ~450-750 m above surface MW OMI MW c003 “Visibility poor; eyes burning in cockpit…” UV T2 J31 track OMI UV c003 AERONET T1 AATS AATS AOD: high variability, flat l depend. 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  20. UV J31 track MW T0 MEX 19 March 2006(over land) Aura overpass: 20.11 UT “Much clearer as we approach T0.” J31 ~450 m above surface OMI MW c003 OMI UV c003 AERONET at T0 AATS AOD: AATS less variability, slightly more l dependence than at T2,T1 Do AODs retrieved by OMI exceed sunphotometer AODs because of an incorrect assumption of surface reflectivity? 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  21. SSFR T0 Surface Albedo Retrievals for 06 & 10 March; OMI Retrieval Surface Albedo Assumptions for 19 March T0 surface albedo* SSFR 15 March T0 surface albedo* SSFR 06 March OMI MW 19 March OMI UV 19 March *Coddington et al., Measurements of areal resolved surface spectral albedo, a sensitivity analysis, and validation of MODIS land albedo product during MILAGRO, submitted to J. Geophys. Res., 2007. 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  22. Single Scattering Albedos for 19 March 2006 and from SSFR/AATS Measurements in Previous Field Campaigns MFRSR T2: 19 Mar 06 [Barnard-Volkamer] OMIMW T0: 19 Mar 06 ACE Asia dust/urban* OMI UV T0: 19 Mar 06 PRIDE Saharan dust* AERONET T0: 19 Mar 06 *Bergstrom et al., Spectral absorption properties of atmospheric aerosols, Atmos. Chem. Phys. Discuss., 7, 10669-10686, 2007. 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  23. Aerosol Absorption Optical Depth for 19 March 2006 OMI MW AERONET T0 OMI UV ACE Asia dust/urban PRIDE Saharan dust AATS 2007 AGU Fall Meeting, A12A-01, 10 December 2007

  24. During MILAGRO/INTEX-B 2006, AATS-14 acquired near-surface AOD measurements coincident with four Aura OMI overpasses: 3 over the Gulf of Mexico and 1 over Mexico City. • Aqua-MODIS AOD retrievals are available for 2 of the 3 over-water AATS/OMI events, and these agree well with the corresponding AATS AOD spectra. For the Mexico City event, AATS AOD spectra agree with coincident surface-based AERONET retrievals at the T0 site. • For all 4 AATS/OMI coincidences during MILAGRO/INTEX-B, OMI near-UV and MW AOD retrievals using C002 radiance data significantly exceed AATS AODs. When C003 radiance data are used for the 3 over-water cases, OMI MW retrievals change very little, but OMI near-UV retrievals decrease markedly and yield a non-absorbing aerosol model. Retrievals for the Mexico City case show little difference between C002 and C003. • AATS/OMI differences may be due to enhanced absorption in the UV due to organic aerosol, any remaining OMI instrument calibration issues, incorrect aerosol height assumption, incorrect surface albedo assumption over Mexico City, or cloud contamination over the Gulf of Mexico. • For the 19 March Mexico City data set, OMI near-UV AOD retrievals near T2 agree well with AERONET AODs. Near T0, OMI near-UV AAOD retrievals and estimated AATS AAOD spectra agree better than do the OMI near-UV and AATS AOD spectra. However, comparisons of OMI MW and estimated AATS AAOD spectra show little improvement in agreement over the OMI MW and AATS AOD comparisons. • Inversions of AERONET direct sun and almucantar measurements acquired at the T0 site in Mexico City on 19 March near (~20 min before and 40 min after) the time of Aura overpass yield SSA values (0.733 and 0.758) at 441 nm that are significantly less than the OMI retrievals. The corresponding AERONET AAOD value of 0.073 falls between corresponding OMI UV and MW retrievals of AAOD. Summary/Conclusions 2007 AGU Fall Meeting, A12A-01, 10 December 2007

More Related