HR: 0800h
AN: B51B-0195    [Abstracts]
TI: Phenology Monitoring in Alaska with GLOBE Data, AVHRR NDVI and the CLAVR Algorithm
AU: * Robin, J
EM: jrobin@ltpmail.gsfc.nasa.gov
AF: University of Maryland-College Park, Geography Department, College Park, MD 20742 United States
AU: Dubayah, R
EM: dubayah@umd.edu
AF: University of Maryland-College Park, Geography Department, College Park, MD 20742 United States
AU: Sparrow, E
EM: ffebs@aurora.uaf.edu
AF: University of Alaska-Fairbanks, Department of Plant, Animal, and Soil Sciences, Fairbanks, AK 99775 United States
AU: Levine, E
EM: elissa@ltpmail.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Biospheric Sciences Branch, Greenbelt, MD 20771 United States
AB: Since 1999, GLOBE students have made over 75,000 phenology measurements at or near their schools and have reported annual dates for bud burst, green-up, leaf growth, and green-down for selected trees, shrubs, and grasses. Students in Alaska have collected nearly half the phenology data. This data set, largely untapped for scientific purposes, provides an exceptional means to validate satellite-derived phenology for Alaska. In this research we analyze the efficacy of phenology monitoring using maximum AVHRR Normalized Difference Vegetation Index (NDVI) composites, both 7 and 14 day, with the CLAVR (Clouds from AVHRR) cloud detection algorithm. Phenology metrics for Anchorage and Fairbanks were calculated from AVHRR. Metrics included start, end, and length of growing seasons for 2001 through 2004. Corresponding field measurements and observations made by GLOBE students in or near Anchorage and Fairbanks were used to validate the derived phenology metrics. Overall, the students' data showed that budburst occurred earlier in 2003 and 2004 while the derived AVHRR phenology metrics showed earlier budburst for 2002 and 2004. This research provides important lessons regarding how well maximum NDVI compositing of AVHRR data and the CLAVR algorithm perform in northern regions (latitudes 60 degrees and greater). These results are applicable to the future National Polar-Orbiting Operational Environmental Satellite System (NPOESS) monthly gridded NDVI product from the Visible Infrared Imager Radiometer Suite (VIIRS), the AVHRR NDVI product successor.
DE: 0434 Data sets
DE: 0480 Remote sensing
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1640 Remote sensing (1855)
DE: 1865 Soils (0486)
SC: Biogeosciences [B]
MN: Fall Meeting 2005