HR: 15:45h
AN: B33D-08    [Abstracts]
TI: Are the terrestrial long-term satellite observations from NOAA AVHRR adequate to justify the Earth Science conclusions that have been based on them?
AU: * Prince, S D
EM: sprince@geog.umd.edu
AF: Geography Department, University of Maryland Rm 2181 LeFrak Hall, College Park, MD 20742-8225 United States
AB: The NOAA Advanced Very High Resolution Radiometer suffers from many disadvantages compared with more recent instruments, yet vegetation and other land surface observations have been made by these instruments for the entire globe since 1981, and they will not be replaced until sometime after 2008 - resulting in at least a 28 year record. The problems of the AVHRR include the lack of post-launch sensor calibration for its visible and near infrared channels; the gradual changes in equatorial crossing time through each satellite's duty cycle so the solar zenith angle of the observations change; the ephermeris and orbital data that are poor by modern standards, which affects the precision possible in mapping the data; the transmission of only a subsample of the measured surface reflected radiances for each pixel; and the few, rather broad spectral bands included in the available channels, which allow only limited atmospheric correction. Notwithstanding these handicaps, significant Earth system science conclusions have already been based on the AVHRR record and these are likely to increase as the length of its record extends. The conclusions relate to global, biome and agricultural primary production; interannual fluctuations in absorption of photosynthetically active radiation and leaf area index; impacts of ENSO on primary production; phenology; and changes in land cover. Such conclusions will be reviewed and their status considered in the light of the signal-noise relationships within the existing AVHRR record and recommendations made on the limits of interpretation possible with existing data sets. The aim will be to establish goals for improvements in post-processing of the long-term AVHRR data set.
DE: 3322 Land/atmosphere interactions
DE: 3360 Remote sensing
DE: 1894 Instruments and techniques
DE: 1640 Remote sensing
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting