albedo cook

7/29/2019 Albedo Cook

1/23

MODIS Albedo Subsets forSelected Field sites

Bob Cook, Steve Margle,Susan Holladay, and Lisa Olsen

Oak Ridge National LaboratoryOak Ridge, Tennessee, USA

2nd CEOS/WGCV/Land Product Validation (LPV)Workshop on Albedo Products

Vienna, AustriaApril 2829, 2005


2/23

2 ORNL DAAC

Collaborators / Contributors

Jeff Morrisette, Nazmi El Saleous(NASA GSFC)

Crystal Schaaf and Ranga Myneni (BostonUniversity)

Steve Running and Faith Ann Heinsch(University of Montana)

Giri Palanisamy and Tammy Beaty (ORNL)


3/23

3 ORNL DAAC

Goal

To provide subsets of MODIS LandProducts in a format and spatial scaleuseful to field investigators

Facilitates interaction between remotesensing scientists and field investigators

Easily compare satellite data with ground-based measurements

Used for validation of MODIS LandProducts


4/23

Subsets of Terra and Aqua MODIS Land Products for 280 sites

worldwide (field sites or flux towers) in an easy-to-use ASCII

format 7 km x 7 km centered on flux tower or field sites

Two annual products, four 8-day products, two 16-day product,

and calculated albedo, from 2000 to present

MODIS ASCII Subsets

MODIS ProductsSurface Reflectance

Surface Temperature

Land Cover

NDVI / EVI

LAI / fPAR

Net Photosynthesis

Annual NPP

Albedo

Reflectance BRDF

Adjusted


5/23

5 ORNL DAAC

MODIS Subset Sites: Albedo Related

BSRN Sites Toravere, Estonia Tateno, Japan

Payerne, Switzerland

Barrow, Alaska

S. Great Plains, Oklahoma

Fort Peck, Montana

Bondville, Illinois

Boulder Colorado

Penn State, Pennsylvania

Goodwin Creek, Mississippi

Other Sites Guzelyayla , Turkey Ovacik, Turkey

Arabia1, Saudi Arabia

Ngotto Forest, Cent.African Rep.

RAC, Central African Republic

Nile Delta, Eqypt

Novara, Italy

Po Valley, Italy

Hapex-Sahel, Niger

Lamto, Cote D'Ivoire

Nigeria, Nigeria Suchow, China

Mammoth Mountain, CA, USA

ARS-NE PLRC, PA, USA

Pleasant Plains, IL, USA

Allegheny Nat. Forest, PA, USA


6/23

6 ORNL DAAC

MODIS Subset Sites: Albedo Related

Greenland (Denmark) Crawford_Point 2

Crawford_Point 1

DYE-2

JAR1

JAR2

Saddle

South Dome

SM2

Summit

ETH/CU Swiss Camp


7/23

MODIS ASCII Subset Web Site: http://www.modis.ornl.gov/modis/


8/23


9/23


10/23


11/23

User-selectsoptical

depth andszn


12/2312 ORNL DAAC

Albedo Calculated from MODIS BRDF Product

MODIS BRDF Albedo Model Product (MOD43B1)contains parameters for calculating albedo forvisible, near-IR, and shortwave

Black Sky albedo

(parm 1, parm 2, parm 3, szn)

White Sky albedo

(parm 1, parm 2, parm 3)

Blue Sky albedo (white sky albedo, black sky albedo, optical

thickness)


13/23


14/2314 ORNL DAAC

Quality Assurance

Provide quality assurance data layers Including snow

Toravere BSRN, Estonia, January 1, 2005


15/2315 ORNL DAAC

Information at bottom of Grid Display


16/23

MODIS ASCII SubsetsWeb-Based Data Visualization: Grid

Toravere BSRN, Estonia


17/2317 ORNL DAAC


18/23

Pixel Values

Mean Value

of Pixels

Percent of

Pixels that met

QC Criteria

Visible Broadband Blue Sky Albedo (fraction)

MODIS ASCII SubsetsWeb-Based Data Visualization: Time Series

Toravere BSRN, Estonia

Year


19/2319 ORNL DAAC

Additional data compiled for albedo validation

Broadband Diffuse Irradiance Climatology forthe selected MODIS ASCII Subset Sites (n =254) Based on AERONET data

Prepared by Privette and Hoffman

Available from ORNLftp://daac.ornl.gov/data/eos_land_val/albedo/

Subsets of Optical Depth (MOD04) for 24 sites; Summit, ETH_CU_Swiss_Camp, Tateno,

Fort_Peck_Montana, Payerne, BARC, Barton_Bendish,BOREAS_BERMS, Jornada, Lake_Tahoe, Mandalgobi,Metolius_Old_Pine, Tapajos, North_Temperate_Lakes

Available from NASA GSFCftp://windhoek.nascom.nasa.gov/private/ichoku/MAPSS/
ftp://daac.ornl.gov/data/eos_land_val/albedo/ftp://windhoek.nascom.nasa.gov/private/ichoku/MAPSS/ftp://windhoek.nascom.nasa.gov/private/ichoku/MAPSS/ftp://daac.ornl.gov/data/eos_land_val/albedo/


20/23

20 ORNL DAAC

Future Plans: MODIS ASCII Subsets

Continue to offer subsets of Collection 4MODIS Land Products from Terra and Aqua

Add Continuous Vegetation Field subsets when

available Evaluate current sites and seek additional sites

for future processing / reprocessing (e.g.,Collection 5 in late-2005)

To have your field site added to the MODIS SubsetCollection, we need the geographic coordinates (tofour significant decimal places; 10s of meters) andyour commitment to share data


21/23

21 ORNL DAAC

1 minute uncertainty yields +/- 2 km or 25 pixels

Uncertainty of

+/- 1 minute

Need site location good to 0.0001 degree


22/23

22 ORNL DAAC

Future Plans: MODIS Subset Pilot

Tool to enable on-the-fly subsetting andvisualization

For any area in North America up to 200 x200 km

For pre-selected sites for the rest of theworld

Incorporate albedo calculation fromMOD43B parameters


23/23

MODIS ASCII Subsets Web Site

www.modis.ornl.gov/modis/

Contact: Bob Cook

ORNL DAAC

[email protected]

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