MISR/MODIS intercomparisons and data fusion

MODIS Science Team Meeting23 March 2005

David J. Diner, MISR Principal Investigator

Jet Propulsion Laboratory,California Institute of Technology

and the MISR team

MISR characteristics

9 view angles at Earth surface:70.5º forward to 70.5º aftward

Four spectral bands at each angle:446 nm ± 21 nm 558 nm ± 15 nm672 nm ± 11 nm866 nm ± 20 nm

275 m sampling in all nadir bands and red band of off-nadir cameras1.1 km for the other channels

400-km swath: Complete zonal coverage 9 days at equator2 days at poles

7 minutes to observe each sceneat all 9 angles

Digitization: 14 bits

Standard products are processed andarchived at the NASA LangleyAtmospheric Sciences Data Center eosweb.larc.nasa.gov

Radiometry

MISR On-Board Calibrator

AirMISR

MISR lunarimages

Railroad Valley

LunarLake Vicarious calibrations and validations

over desert playas and dark water sites

MISR calibration

A comprehensive review of thesedata sources in 2003-2004 led todownward revision of the MISRradiances by 3% in the red and 2% in the NIR

MISR ocean aerosol optical depths prior to 2004 calibration revision

MISR-AERONET difference was ~0.05 at 558 nm

Similar differences were seen with airborne sunphotometer (AATS-14) data and with MODIS

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DIS

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MISR AODR. Kahn, W-H. Li, W. Abdou, L. Remer

Effect of recent product revisions on retrieved MISR AOD over water

AOD, old calibration

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AOD, 24 mixturesAOD, old dust models

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Calibration revisions New dust models

R. Kahn, O. Kalashnikova, D. Diner

Initial MISR-AERONET-AATS 14 comparisons suggest that the MISR ocean AOD bias has been eliminated

Medium-sized weakly-absorbing (1% hematite) grain-shaped dust models provide the best fit to MISR radiances over dust plumes

Comparison of revised radiometric scale with5 years of MISR vicarious calibration history

C. Bruegge, W. Abdou

An camera vicarious calibration results

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Blue Green Red NIR

06-Jun-2000: LL

30-Jun-2001: RRV

10-Jun-2002: Ivan

07-Jul-2003: BRD

22-Jul-2003: RRV

22-Jun-2004: RRV

10-Jun-2002: RRV

13-Jun-2003: RRV

29-Jun-2004: RRV

Mean

center of field of viewedge of field of view

MISR revised calibration compared to MODIS and other sensors

C. Bruegge, W. Abdou

Railroad Valley22-July-2003

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Wavelength (nm)

Radiance (W m-2 sr-1 um-1)

MISR

AirMISR

MERIS

MODIS

Landsat

VC MISR

MISR/MODIS radiance intercomparison in the Arctic

Arctic Ocean/Greenland/Baffin Bay/Baffin IslandTerra path 26—15 orbits from 2002

Red band

E. Clothiaux

MODIS image

Details of MISR/MODIS radiance intercomparison

MISR-MODIS difference (%)as function of radiance

MISR-MODIS difference (%)as function of location

MISR: 672 nmMODIS: 645 nmNot adjusted for spectral shift, ozone

E. Clothiaux

Terminator:long solar slant path

Dark, openwater

3% difference

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Aerosols and cirrus

MISR/MODIS standard product complementarity:MISR retrievals over brightsurfaces

R. Kahn, J. Martonchik, W. Abdou, B. Gaitley, D. Diner

Scattering angle (deg)

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O. Kalashnikova, R. Kahn, D. Diner

Synergistic sensitivities to aerosol particle properties

MODIS: broad spectral coverageenhances sensitivity to size, particularly coarse mode

MISR: multiangle dataprovides sensitivity to shape

MISR/MODIS cirrus case study at ARM Oklahoma site

MISR nadir view image

Millimeter wave radar reflectivity

Ice scattering properties from Yang et al. (2000)

S. McFarlane, R. Marchand, T. Ackerman

MISR is sensitive to particle shapeMODIS is sensitive to particle size

Ice scattering properties from Yang et al. (2000)

Cloud structure, heights, and detection

Morphological diversity of marine stratocumulus clouds

R. Davies

A. Horvath, R. Davies

Multiangle data provides a physical consistency check on MODIS 1-D cloud retrieval assumption

Cloud morphology, along with cloud microphysics, plays a major role in determining TOA bidirectional reflectance

Multiangle tests of cloud homogeneity

1-D theory fits MISR observations

1-D theory does not fit MISR observations

A. Horvath, R. Davies

Application to retrievals of cloud liquid water: MODIS/MISR/TMI fusion

Reasonable consistency (±25%) is obtained between MODIS and TRMM Microwave Imager (TMI) LWP for shallow, boundary layer clouds.

MISR is used as a check on the applicability of 1-D retrieval theory.

MODIS/TMI consistency is much poorer for deep clouds.

MISR 60º image of deep cloud

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view zenith angle (degree)

boundary layer clouds

MISR allTMI all TMI all +/- 15%

MISR overcast TMI overcast TMI overcast +/- 15%

TMI LWP (g/m2)

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boundary layerclouds

nadir only nadir+60°

cloud vertical extent no information 10.5 ± 0.8 km

extinction coefficient no information8 - 22 km-1

(higher at base)

cloud optical depth > 60 150 ± 30

Oblique views make it possible to scan down the sides of deep clouds:

MISR stereo retrievals of cloud top heights (CTH)

Trade wind cumuli: high sensitivity

Typhoon Sinlaku

MISR cloud heights --independent of radiometric calibration, atmospheric temperature profiles, cloud emissivity

0 2.5 5 km

ARM BarrowARM NauruARM SGP

Comparison of MISR stereo heights with radar/lidar

Clear-sky or opaque cloud topBroken boundary layer cloudsSemi-opaque cirrusThin cloud over other clouds (MISR determines the height of the lower cloud tops)Thin cloud over surface

MISR stereo heightRad

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MISR stereo heightMISR stereo height

R. Marchand, T. Ackerman

MISR/MODIS CTH comparisons

MISR and MODIS in good agreement for single-level mid-high clouds (accuracy ~500 m)

MISR performs well for low clouds, MODIS 11 m brightness temperatures problematic

Multi-layer situations problematic for MISR operational (near-nadir) stereo, altitude detected depends on high cloud optical depth

Typically MODIS CTH > MISR CTH (difference ~600 m)C. Naud, J-P. Muller, E. Clothiaux

ChilboltonARM SGP

Discriminating polar clouds from snow and ice with MISR

L. Di Girolamo, M. Wilson, C.Moroney

-0.5 0.5 1.5 2.5BDAS

0.0 0.2 0.4 0.6 0.8Red BRF (nadir)

Red band bidirectional reflectance factor

Band-differencedangular signature

Antarctica, 2 April 2001

Angular reflectance signature

Stereoscopically-derivedcloud-top height

Bidirectional reflectance factor

Arctic, near Queen Elizabeth Islands, 28 August 2000

Stereo

Strength of MISR/MODIS fusion for polar clouds

Overall classification accuracies relative to “expert” labels

MODIS: 86% [detects the highest cloud, whether optically thick or thin]

MISR stereo only: 75% [locates the first (from space) optically thicksurface; thin clouds problematic for near-nadir stereo]

MISR stereo + angular signatures: 92%

MISR + MODIS: 95-97%

Terra CERES-MISR-MODIS fusion Capitalizes on excellent separation of clouds from ice for understanding polar radiation budget

CALIPSO and CloudSat synergy can be used to quantify cloud optical depths giving rise to MODIS high cloud/MISR low cloud detections

T. Shi, B. Yu, A. Braverman, D. Groff, E. Clothiaux

Arctic Ocean/Greenland/Baffin Bay/Baffin IslandTerra path 26—15 orbits from daylight season of 2002

Fires and smoke

TOMS Aerosol Index (AI)Direct height retrieval ofUT/LS smoke from theChisholm fire, 29 May 2001

MISR

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are needed to see this picture.

MODIS

M. Fromm, D. Diner, C. Moroney, C. Averill

near-nadirstereo

obliquestereo

MODIS fire/MISR stereo fusion for wildfire studies

Southern California, 26 October 2003

MODIS:Thermal channelspinpoints fire locations

MISR:Oblique views enhanceplume sensitivity

Stereo retrieves plume heights

Provides smoke injectiondata for CTMs

Vegetation

Example of MISR surface directional reflectance retrieval

J. Martonchik

MISR/MODIS land surfaceproduct intercomparisons

Land surface albedo(B. Pinty, S. Liang, H. Fang)

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LAI

Days (Year 2000)MODIS MISR days 1 2 3 4 5 6 7 8

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

SALSA San Pedro (Shrubland/Woodland)

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FPAR

Days (Year 2000)MODIS MISR days 1 2 3 4 5 6 7 8

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

SALSA San Pedro (Shrubland/Woodland)

LAI/FPAR over sparsely vegetated land (shrubs account for 25% of global vegetation) (R. Myneni, Y. Knyazikhin, J. Hu)

Bell-shaped BRF:Tree crowns ofmedium-high densityagainst bright background

Bowl-shaped BRF:Sparse vegetationand dense,closed canopies

B. Pinty, N. Gobron, J-L. Widlowski, M. Verstraete

MISR/MODIS synergy/fusion over land surfaces

MISR along-track multiangle data provide independent structural information

MISR/MODIS fusion studies:B. Braswell et al.: Amazon deforestation and regrowthM. Chopping et al.: Woody biomass incursion into arid grasslands

Map: Australian Surveying and Land Information Group

Conclusions

Simultaneous broad spectral coverage from MODIS and wide angular coverage from MISR makes a uniquely valuable combination:

Having independent retrievals of related parameters from each sensor using different methodologies is a key element of a robust observing system.

Data fusion capitalizes on complementary sensitivities to aerosol, cloud, and surface properties.

MISR/MODIS data fusion is currently being done in research mode

Products using joint retrievals can be considered—AerosolsPolar cloudsFiresLand surface

Some of these were described in the Terra extension proposal (Senior Review).

Joint data analysis tool development would also be a great benefit to the scientific community.