HR: 16:45h
AN: B44A-03    [Abstracts]
TI: Monitoring Phenological Trends From Satellite Imagery
AU: * Reed, B
EM: reed@usgs.gov
AF: SAIC, USGS EROS Data Center 47914 252nd St., Sioux Falls, SD 57198 United States
AU: Brown, J
EM: jfbrown@usgs.gov
AF: SAIC, USGS EROS Data Center 47914 252nd St., Sioux Falls, SD 57198 United States
AU: Whalen, A
EM: awhalen@usgs.gov
AF: SAIC, USGS EROS Data Center 47914 252nd St., Sioux Falls, SD 57198 United States
AB: While there is convincing evidence that global climate change is taking place, there is still considerable controversy over the magnitude and consequences of any changes. One of the primary manifestations of climate change is the effect on patterns of vegetation growth; the timing of the growing season, the vigor of vegetation, and vegetation composition. The satellite data record provides an objective view of vegetation activity by measuring surface reflectance values at regular time intervals. Time-series analyses of satellite data can provide information on emerging trends of vegetation dynamics that may be related to global change. The objective of this project is to conduct a trend analysis of vegetation dynamics in the conterminous United States, as measured by satellite data, to assess regions of changing vegetation activity, and to evaluate the regions to determine the driving forces of these changes. To assess vegetation dynamics we analyze phenological metrics (e.g., time of start of season , end of season, duration of season, and seasonally integrated greenness) derived from satellite data and evaluate trends in these metrics by studying the climate record, agricultural statistics, and land cover data bases to assess the driving forces of the trends. The types of trends that we identify include trends toward earlier/later start and end of season, longer/shorter growing seasons, and greater/lesser vegetation production. Early results indicate geographically specific drivers across various ecoregions of the US.
DE: 1694 Instruments and techniques
DE: 1640 Remote sensing
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting