HR: 16:00h
AN: B54A-01 INVITED     [Abstracts]
TI: Large-Scale Disturbance Events in Terrestrial Ecosystems Detected using Global Satellite Data Sets
AU: * Potter, C
EM: cpotter@mail.arc.nasa.gov
AF: NASA Ames Research Center, Mail Stop 242-4, Moffett Field, CA 94035 United States
AU: Tan, P
EM: ptan@cse.msu.edu
AF: Michigan State University, Computer Science, East Lansing, MI 48824 United States
AU: Kumar, V
EM: kumar@cs.umn.edu
AF: University of Minnesota, Computer Science, Minneapolis, MN 55455 United States
AU: Klooster, S
EM: sklooster@mail.arc.nasa.gov
AF: California State University Monterey Bay, NASA/ARC, Seaside, CA 93955 United States
AB: Studies are being conducted to evaluate patterns in a 19-year record of global satellite observations of vegetation phenology from the Advanced Very High Resolution Radiometer (AVHRR), as a means to characterize large-scale ecosystem disturbance events and regimes. The fraction absorbed of photosynthetically active radiation (FPAR) by vegetation canopies worldwide has been computed at a monthly time interval from 1982 to 2000 and gridded at a spatial resolution of 8-km globally. Potential disturbance events were identified in the FPAR time series by locating anomalously low values (FPAR-LO) that lasted longer than 12 consecutive months at any 8-km pixel. We can find verifiable evidence of numerous disturbance types across North America, including major regional patterns of cold and heat waves, forest fires, tropical storms, and large-scale forest logging. Based on this analysis, an historical picture is emerging of periodic droughts and heat waves, possibly coupled with herbivorous insect outbreaks, as among the most important causes of ecosystem disturbance in North America. In South America, large areas of northeastern Brazil appear to have been impacted in the early 1990s by severe drought. Amazon tropical forest disturbance can be detected at large scales particularly in the mid 1990s. In Asia, large-scale disturbance events appear in the mid 1980s and the late 1990s across boreal and temperate forest zones, as well as in cropland areas of western India. In northern Europe and central Africa, large-scale forest disturbance appears in the mid 1990s.
UR: http://geo.arc.nasa.gov/sge/casa/
DE: 1615 Biogeochemical processes (4805)
DE: 1620 Climate dynamics (3309)
DE: 1640 Remote sensing
DE: 0315 Biosphere/atmosphere interactions
DE: 0325 Evolution of the atmosphere
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting