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T2 T1 (biomass burning aerosol) (dust) Findings (1) OMI and AATS AOD retrievals have been analyzed...
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T2 T1 (biomass burning aerosol) (dus t) Findings (1) OMI and AATS AOD retrievals have been analyzed for four spatially and temporally near-coincident events during MILAGRO/INTEX-B: three over the Gulf of Mexico and one over the Mexico City metropolitan area. (2) For the March 10 coincidence, the OMAERO algorithm retrieves a biomass burning aerosol and the corresponding AOD retrievals significantly exceed AATS and MODIS values in all 7 OMI grid cells, of which at least 4 were cloud-free. When the retrieval was restricted to weakly absorbing (sulfate) aerosol models, AODs decreased and the agreement with AATS and MODIS improved significantly. (3) The OMAERUV algorithm retrieves a non-absorbing sulfate aerosol model for all 3 over-water events, and AOD retrievals significantly underestimate AATS values for all cloud-free grid cells on March 10. (4) On March 19, AATS measured a wide range of AOD at altitudes ~480 m above the T2 site ~70 km NE of the Mexico City metropolitan area. AATS spectra were flat, indicative of dust. Corresponding OMAERUV AOD retrievals agree with AERONET AOD spectra, which exceed the AATS values that were not corrected for AOD below the J31 aircraft. OMAERO AOD spectra significantly exceed the sunphotometer and OMAERUV values. (5) AATS AOD spectra ~420 m above the T0 site near the heart of Mexico City agree with AERONET measurements and exhibit a steeper wavelength dependence (~0.6-0.7). OMAERUV retrievals slightly exceed and OMAERO retrievals significantly exceed the AATS and AERONET AODs. (6) Preliminary analysis of measurements acquired on June 30, 2008 during ARCTAS Abstra ct During the fall 2007 Aura Science Team Meeting, we presented comparisons of aerosol optical depths retrieved from spatially and temporally near-coincident measurements acquired during March 2006 during MILAGRO/INTEX-B (Megacity Initiative-Local And Global Research Observations/Phase B of the Intercontinental Chemical Transport Experiment) by the NASA Ames Airborne Tracking Sunphotometer (AATS) and by Aura OMI. Results were shown for three AATS/OMI coincidences over the Gulf of Mexico, two of which also included Aqua MODIS AOD retrievals, and one over the Mexico City area. We showed OMAERUV results derived from the OMI Collection 002 radiances, and preliminary OMAERO results derived from the Collection 003 radiances. In this presentation, we update those comparisons using the final archived OMAERO and OMAERUV retrievals derived from the Collection 003 radiances. In addition, we show a preliminary comparison of AATS, OMI, and MODIS AOD retrievals from measurements acquired over the boreal forests of Canada during the summer 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field deployment. During ARCTAS, AATS was flown aboard the NASA P-3B research aircraft together with a variety of other remotely sensing atmospheric radiation instruments and in situ particle and gas sensors. Data were obtained in clear air and through forest fire smoke plumes directly over and at various distances downwind of boreal forest fires. Comparison of Airborne Sunphotometer and OMI Retrievals of Aerosol Optical Depth during MILAGRO/INTEX-B and ARCTAS J. Livingston 1 , J. Redemann 2 , Y. Shinozuka 3 , P. Russell 3 , O. Torres 4 , B. Veihelmann 5 , R. Braak 5 , R. Johnson 3 , S. Ramachandran 3,6 , L. Remer 7 , R. Levy 7,8 , A. Smirnov 7,8 , B. Holben 7 , C. McNaughton 9 , Q. Zhang 2 , S. Ramirez 2 1 SRI International, Menlo Park, CA, 2 Bay Area Environmental Research Institute, Sonoma, CA, 3 NASA Ames Research Center, Moffett Field, CA, 4 Center for Atmospheric Sciences, Hampton University, Hampton, VA, USA, 5 Royal Netherlands Meteorological Institute (KNMI), DeBilt, The Netherlands, 6 Physical Research Laboratory, Ahmedabad, INDIA, 7 NASA Goddard Space Flight Center, Greenbelt, MD, USA, 8 Science Systems and Applications, Inc., Lanham, MD USA, 9 University of Hawaii, Honolulu, HI USA MILAGRO (March 2006):4 AATS/OMI Coincidences 10 March 2006 3 March 2006 17 March 2006 ARCTAS (Summer 2008): 3 AATS/OMI Coincidences MODIS values represent mean for all MODIS grid cells intersecting the OMAERUV grid cell; vertical bars delineate range of AODs. AATS and OMI values are interpolated to 466 nm. 19 March 2006 T0 T2 AATS AAOD estimated using Bergstrom et al. SSA () smoke smoke weakly absorbing smok e weakly absorbing weakly absorbing smoke smoke smoke smoke smoke smoke Highlighted cells probably cloud- contaminated. Note: cloud-clearing turned off for OMAERO retrievals. AATS and OMAERO AOD Spectra 30 June 2008: PRELIMINARY RESULTS MODIS AOD MODIS % cloud P-3B flight track color-coded by AATS AOD (451 nm) OMAERUV (470 nm) OMAERO MODIS smoke plume AATS and OMAERUV AOD Spectra MODIS cloud percentages suggest cells highlighted in yellow are cloud-contaminated. AATS did not measure large AODS along P-3B track across the western end of dark blue OMI grid cell, but MODIS AOD on the eastern end is elevated, so larger OMI AODs seem consistent. sulfat e smoke smoke sulfat e sulfa te sulfat e smoke smoke MODIS % cloud grid cell J31 low altitude (~60 m ASL) flight track grid cell grid cell OMAERO OMAERUV MODIS >90 J31 low altitude transect Photo from DC-8 toward Mexico City AATS AAOD estimated using Bergstrom et al. SSA () biomass burning aerosol dust OMAERUV OMAERO AERONET sites at T2, T1, T0 J31 flight track color-coded by GPS altitude Aura overpass: 20.11 UT June 30 July 3 July 9 OMAERO (no BBDD): Retrieval restricted to weakly absorbing aerosol models (no biomass burning or desert dust allowed). Aura overpass: 20.21 UT biomass burning non- absorbing sulfate J31 low altitude transect Aura overpass: 20.11 UT biomass burning aerosol non- absorbing sulfate J31 low altitude transect Note high MODIS cloud fractions over the flight track and the eastern portion of the OMI retrieval grid cells. MODIS %cloud J31 low altitude flight track 19.420-19.526 UT Aura overpass: 20.32 UT biomass-burning weakly absorbing non-absorbing sulfate OMAERO retrieval in dark blue cell is likely cloud-contaminated. Even OMI retrievals in cyan cells may be cloud- contaminated. For OMAERUV retrievals, vertical bars show estimated uncertainties. For AATS, circles represent the mean and vertical bars give the range of AODs within the OMI grid cell. AATS measurement uncertainties are not shown, as they are smaller than the circles. AATS, OMAERO, and OMAERUV all observed an AOD gradient increasing from N to S over the northern half of the J31 track, despite differences in AOD magnitudes and in the magnitude of the AOD gradient. MODIS AOD retrievals are plotted with color-coded solid circles; vertical bars give the expected uncertainty for an over-land retrieval. Black squares show the AATS AOD means for all cloud-free measurements acquired along the segment of the aircraft track that intersects the particular MODIS grid cell; vertical bars delineate the range of AODs measured in the cell. AATS measurement uncertainties are not shown, as they are smaller than the square symbols. AATS and MODIS AOD Spectra Blue envelope shows expected uncertainty in MODIS over-water AOD retrievals. MODIS retrievals in olive-colored grid cell with 79% cloud; omitted in rms and bias statistics.
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Transcript of T2 T1 (biomass burning aerosol) (dust) Findings (1) OMI and AATS AOD retrievals have been analyzed...
T2
T1
(biomass burning aerosol)
(dust)
Findings
(1) OMI and AATS AOD retrievals have been analyzed for four spatially and temporally near-coincident events during MILAGRO/INTEX-B: three over the Gulf of Mexico and one over the Mexico City metropolitan area.
(2) For the March 10 coincidence, the OMAERO algorithm retrieves a biomass burning aerosol and the corresponding AOD retrievals significantly exceed AATS and MODIS values in all 7 OMI grid cells, of which at least 4 were cloud-free. When the retrieval was restricted to weakly absorbing (sulfate) aerosol models, AODs decreased and the agreement with AATS and MODIS improved significantly.
(3) The OMAERUV algorithm retrieves a non-absorbing sulfate aerosol model for all 3 over-water events, and AOD retrievals significantly underestimate AATS values for all cloud-free grid cells on March 10.
(4) On March 19, AATS measured a wide range of AOD at altitudes ~480 m above the T2 site ~70 km NE of the Mexico City metropolitan area. AATS spectra were flat, indicative of dust. Corresponding OMAERUV AOD retrievals agree with AERONET AOD spectra, which exceed the AATS values that were not corrected for AOD below the J31 aircraft. OMAERO AOD spectra significantly exceed the sunphotometer and OMAERUV values.
(5) AATS AOD spectra ~420 m above the T0 site near the heart of Mexico City agree with AERONET measurements and exhibit a steeper wavelength dependence (~0.6-0.7). OMAERUV retrievals slightly exceed and OMAERO retrievals significantly exceed the AATS and AERONET AODs.
(6) Preliminary analysis of measurements acquired on June 30, 2008 during ARCTAS indicate that the AATS, OMI, and MODIS AOD retrievals appear to paint a consistent picture through the smoke plume, despite differences in the retrieved OMI aerosol models and in retrieved AODs outside the smoke.
AbstractDuring the fall 2007 Aura Science Team Meeting, we presented comparisons of aerosol optical depths retrieved from spatially and temporally near-coincident measurements acquired during March 2006 during MILAGRO/INTEX-B (Megacity Initiative-Local And Global Research Observations/Phase B of the Intercontinental Chemical Transport Experiment) by the NASA Ames Airborne Tracking Sunphotometer (AATS) and by Aura OMI. Results were shown for three AATS/OMI coincidences over the Gulf of Mexico, two of which also included Aqua MODIS AOD retrievals, and one over the Mexico City area. We showed OMAERUV results derived from the OMI Collection 002 radiances, and preliminary OMAERO results derived from the Collection 003 radiances. In this presentation, we update those comparisons using the final archived OMAERO and OMAERUV retrievals derived from the Collection 003 radiances.
In addition, we show a preliminary comparison of AATS, OMI, and MODIS AOD retrievals from measurements acquired over the boreal forests of Canada during the summer 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field deployment. During ARCTAS, AATS was flown aboard the NASA P-3B research aircraft together with a variety of other remotely sensing atmospheric radiation instruments and in situ particle and gas sensors. Data were obtained in clear air and through forest fire smoke plumes directly over and at various distances downwind of boreal forest fires.
Comparison of Airborne Sunphotometer and OMI Retrievals of Aerosol Optical Depth during MILAGRO/INTEX-B and ARCTAS
J. Livingston1, J. Redemann2, Y. Shinozuka3, P. Russell3, O. Torres4, B. Veihelmann5, R. Braak5, R. Johnson3, S. Ramachandran3,6, L. Remer7, R. Levy7,8, A. Smirnov7,8, B. Holben7, C. McNaughton9, Q. Zhang2, S. Ramirez2
1SRI International, Menlo Park, CA, 2Bay Area Environmental Research Institute, Sonoma, CA, 3NASA Ames Research Center, Moffett Field, CA, 4Center for Atmospheric Sciences, Hampton University, Hampton, VA, USA, 5Royal Netherlands Meteorological Institute (KNMI), DeBilt, The Netherlands, 6Physical Research Laboratory, Ahmedabad, INDIA, 7NASA Goddard Space Flight Center, Greenbelt, MD, USA, 8Science Systems and Applications, Inc., Lanham, MD USA, 9University of Hawaii, Honolulu, HI USA
MILAGRO (March 2006):4 AATS/OMI Coincidences
10 March 2006
3 March 2006 17 March 2006
ARCTAS (Summer 2008): 3 AATS/OMI Coincidences
MODIS values represent mean for all MODIS grid cells intersecting the OMAERUV grid cell; vertical bars delineate range of AODs. AATS and OMI values are interpolated to 466 nm.
19 March 2006
T0
T2
AATS AAOD estimated using Bergstrom et al. SSA ()
smokesmoke
weakly absorbing smokeweakly absorbing
weakly absorbing
smoke
smokesmokesmoke
smoke
smoke
Highlighted cells probably cloud-contaminated.
Note: cloud-clearing turned off for OMAERO retrievals.
AATS and OMAERO AOD Spectra
30 June 2008: PRELIMINARY RESULTS
MODIS AOD
MODIS % cloud
P-3B flight track color-coded by AATS AOD (451 nm)
OMAERUV
(470 nm)
OMAERO
MODIS
smoke plume
AATS and OMAERUV AOD Spectra
MODIS cloud percentages suggest cells highlighted in yellow are cloud-contaminated.
AATS did not measure large AODS along P-3B track across the western end of dark blue OMI grid cell, but MODIS AOD on the eastern end is elevated, so larger OMI AODs seem consistent.
sulfate smoke
smokesulfate sulfate
sulfate
smoke smoke
MODIS % cloud
grid cell
J31 low altitude (~60 m ASL) flight track
grid cell
grid cell
OMAEROOMAERUV
MODIS
>90
J31 low altitude transect
Photo from DC-8 toward Mexico City
AATS AAOD estimated using Bergstrom et al. SSA ()
biomass burning aerosol
dust
OMAERUV
OMAERO
AERONET sites at T2, T1, T0
J31 flight track color-coded by GPS altitude
Aura overpass: 20.11 UT
June 30
July 3
July 9
OMAERO (no BBDD): Retrieval restricted to weakly absorbing aerosol models (no biomass burning or desert dust allowed).
Aura overpass: 20.21 UT
biomass burning
non-absorbing sulfate
J31 low altitude transect
Aura overpass: 20.11 UT
biomass burning aerosol
non-absorbing sulfate
J31 low altitude transect
Note high MODIS cloud fractions over the flight track and the eastern portion of the OMI retrieval grid cells.
MODIS %cloud
J31 low altitude flight track 19.420-19.526 UT
Aura overpass: 20.32 UT
biomass-burning
weakly absorbing
non-absorbing sulfate
OMAERO retrieval in dark blue cell is likely cloud-contaminated. Even OMI retrievals in cyan cells may be cloud-contaminated.
For OMAERUV retrievals, vertical bars show estimated uncertainties. For AATS, circles represent the mean and vertical bars give the range of AODs within the OMI grid cell. AATS measurement uncertainties are not shown, as they are smaller than the circles. AATS, OMAERO, and OMAERUV all observed an AOD gradient increasing from N to S over the northern half of the J31 track, despite differences in AOD magnitudes and in the magnitude of the AOD gradient.
MODIS AOD retrievals are plotted with color-coded solid circles; vertical bars give the expected uncertainty for an over-land retrieval. Black squares show the AATS AOD means for all cloud-free measurements acquired along the segment of the aircraft track that intersects the particular MODIS grid cell; vertical bars delineate the range of AODs measured in the cell. AATS measurement uncertainties are not shown, as they are smaller than the square symbols.
AATS and MODIS AOD Spectra
Blue envelope shows expected uncertainty in MODIS over-water AOD retrievals.
MODIS retrievals in olive-colored grid cell with 79% cloud; omitted in rms and bias statistics.
