1. Spatially Complete Global Surface Albedos Derived from Terra/MODIS Data Michael D. King, 1 Eric G. Moody, 1,2 Crystal B. Schaaf, 3 and Steven Platnick 1 1 NASA Goddard Space Flight Center 2 L3-Communications GSI 3 Boston University  Operational MODIS surface albedo data product (MOD43B3/MCD43B3) –0.47, 0.56, 0.67, 0.86, 1.24, 1.64, 2.1 µm, 0.3-5.0, 0.7-5.0, 0.3-0.7 µm –1 km spatial resolution (sinusoidal projection stored as 10° x 10° tiles) –16-day periodicity (001, 017, …, 353)  Limitations –Spatial and temporal gaps due to cloud cover and seasonal snow  Motivation –Ancillary input for ground-based (AERONET), airborne, and satellite remote sensing –Land surface and climate modeling –Global change research projects

2. Conditioned MOD43B3 Albedo Maps = 0.858 µm

3. IGBP Ecosystem Classification (MOD12Q1) 0 Water 5 Mixed Forests 6 Closed Shrublands 11 Permanent Wetlands 12 Croplands 1 Evergreen Needleleaf Forest 2 Evergreen Broadleaf Forest 3 Deciduous Needleleaf Forest 4 Deciduous Broadleaf Forest 7 Open Shrublands 8 Woody Savannas 9 Savannas 10 Grasslands 13 Urban and Built-Up 14 Cropland/Natural Veg. Mosaic 15 Snow and Ice 16 Barren or Sparsely Vegetated

4. Grasslands7.30% Equal Area IGBP Ecosystem Classification Statistics Evrg. Broad Forest 10.38% Evrg. Needle Forest 4.19% Barren / Desert 13.00% Urban 0.17% Crop Mosaic 3.34% Permanent Snow 11.31% Cropland 10.09% Wetlands 0.33% Savanna 6.63% Woody Savanna 6.32% Open Shrubs 18.86% Closed Shrubs 0.63% Other Veg 13.93 % Mixed Forest 4.85% Decd. Broad Forest 1.19% Decd. Needle Forest 1.40%

5.  Compute regional ecosystem statistics –0.5°, 1-5°, 10°, 10°x20°, 10°x30° box sizes  Obtain pixel-level and regional ecosystem statistical phenological trends –Curves will have different magnitudes –Shapes will be consistent  Impose shape of curves onto pixel level data –Only 10-15% of pixels have adequate coverage to obtain phenology –Maintains pixel level detail with appropriate phenology  Select curve that has best representation –Representation of existing pixel data –Completeness of trend –Bias towards smaller statistical box sizes  Fill missing values with selected curve General Methodology

6. Phenological Curves for Deciduous Broadleaf Forest Vermont, USA Phenological Curves Phenological Curves with Offset Applied

7. Continental United States July 12-27, 2002

8.  Cloud and snow cover obscure full decay state  Over hemisphere average of high latitudes –Unique ecosystem and wavelength extrema percent change –Compute % change from pixels with adequate representation  For each pixel/statistical curve –Pin winter endpoints with value computed from Percent change Percent change Summer extrema Summer extrema  Then apply General Methodology Seasonal Snow Methodology

9. Phenological Curve for Mixed Forest Northern Russia

10. Europe and Western Asia December 3-18, 2002

11.  Clouds obscure trends over large regions –Usually full growth stage is obscured –Even 10°x30° boxes may not observe complete temporal trend  Compute 1 statistical curve per ecosystem class –5°-15° Latitude belts Centered around pixel’s latitude Centered around pixel’s latitude –Yearly phenological behavior curves Instead of 2 half year curves Instead of 2 half year curves  Impose shape of curve onto existing pixel data Persistent Cloud Methodology

12. Missing Season Asian Monsoon

13. Indian Subcontinent during Monsoon June 10-26, 2002

14. Limited Yearly Data Tropical Cloudiness

15. South America during Rainy Season June 10-26, 2002

16. Africa in the Presence of Persistent Clouds December 3-18, 2002

17. Spatially Complete Albedo Maps = 0.858 µm

18. Spectral Variability by Ecosystem Class June 26 - July 11, 2001

19. Temporal Variability by Ecosystem Class January - July 2001 Cropland Ecosystem Urban Ecosystem

20.  2001-2005 (v4) spatially complete albedo maps –Maps and QA stored in 1-minute rectangular coordinates –First seven MODIS wavelengths and 3 broadband –White- and black-sky albedo values  2001-2005 (v4) statistics of filled albedo maps –0.5°, 1°, 2°, 3°, 4°, 5°, 10° box sizes –Statistics computed in boxes and by ecosystem class in boxes  Statistics of snow albedos –Hemispheric averages of MOD43B3 validated data  IGBP ecosystem classification map –Maps and QA stored in 1-minute rectangular coordinates Available Products

21. Land Surface Albedo Data Distribution modis-atmos.gsfc.nasa.gov  Acquiring data –Anonymous FTP Via website Via website Direct link Direct link –Available Albedo maps Albedo maps Albedo QA maps Albedo QA maps Albedo statistics Albedo statistics Ecosystem map Ecosystem map Snow albedo statistics Snow albedo statistics NDVI NDVI Images and movies Images and movies

22.  Used near real-time ice and snow extent (NISE) dataset –Distinguishes land snow and sea ice (away from coastal regions) –Identifies snow Projected onto an equal-area 1’ angle grid Projected onto an equal-area 1’ angle grid  Aggregate snow albedo from MOD43B3 product –Surface albedo flagged as snow Aggregate only snow pixels whose composite NISE snow type is >90% and flagged as snow in any 16-day period Aggregate only snow pixels whose composite NISE snow type is >90% and flagged as snow in any 16-day period –Hemispherical multiyear statistics Separate spectral albedo by ecosystem (MOD12Q1) Separate spectral albedo by ecosystem (MOD12Q1)  Results represent ‘average’ snow conditions –Additional sources of variability include snow depth, snow age, grain size, contamination (soot), and, in the case of black-sky albedo, solar zenith angle Spectral Albedo of Snow

23. Snow Albedo by IGBP Ecosystem Northern Hemisphere Multiyear Average (2000-2004)

24. Spatially Complete White-Sky Albedo January 1-16, 2002 0.6 0.8 0.0 0.2 Surface Albedo (0.86 µm) 0.4 Snow-free Snow-covered

25.  Spatially complete surface albedo datasets have been generated –Uses high-quality operational MODIS surface albedo dataset –Imposes phenological curve and ecosystem-dependent variability –White- and black-sky albedos produced for 7 spectral bands and 3 broadbands  See modis-atmos.gsfc.nasa.gov for data access and further descriptions, and – –Moody, E. G., M. D. King, S., Platnick, C. B. Schaaf, and F. Gao, 2005: Spatially complete global spectral surface albedos: Value-added datasets derived from Terra MODIS land products. IEEE Trans. Geosci. Remote Sens., 43, 144-158.  Spectral albedo of snow –Hemispheric averages of MOD43B3 validated data –Separated by ecosystem class and NISE classification –Additional variability due to snow depth, age, grain size, and contamination not accessible from MODIS data alone, and hence not incorporated Summary and Conclusions