HR: 17:45h
AN: OS22D-08    [PDF]
TI: Clues to Coral Reef Ecosystem Health: Spectral Analysis Coupled with Radiative Transfer Modeling
AU: * Guild, L
EM: lguild@mail.arc.nasa.gov
AF: NASA Ames Research Center, MS 242-4 Ecosystem Science and Technology Branch, Moffett Field, CA 94035-1000 United States
AU: Ganapol, B
EM: GANAPOL@cowboy.ame.arizona.edu
AF: University of Arizona, Departments of Aerospace and Mechanical Engineering and Hydrology and Water Resources, Tucson, AZ 85721-0020 United States
AU: Kramer, P
EM: pkramer@rsmas.miami.edu
AF: University of Miami, Rosentiel School of Marine and Atmospheric Sciences 4600 Rickenbacker Cswy, Miami, FL 33149
AU: Armstrong, R
EM: neptune@caribe.net
AF: University of Puerto Rico, Department of Marine Sciences Isla Magueyes Field Statio La Parguera, Lajas, PR 00667 United States
AU: Gleason, A
EM: art.gleason@miami.edu
AF: University of Miami, Rosentiel School of Marine and Atmospheric Sciences 4600 Rickenbacker Cswy, Miami, FL 33149
AU: Torres, J
EM: jtorres@caribe.net
AF: University of Puerto Rico, Department of Marine Sciences Isla Magueyes Field Statio La Parguera, Lajas, PR 00667 United States
AU: Johnson, L
EM: ljohnson@mail.arc.nasa.gov
AF: CSU Monterey Bay, MS 242-4 NASA Ames Research Center, Moffett Field, CA 94035-1000 United States
AU: Garfield, N
EM: garfield@sfsu.edu
AF: San Francisco State University, Romberg Tiburon Center 3152 Paradise Dr., Tiburon, CA 94920 United States
AB: Coral reefs are among the world's most productive and biologically rich ecosystems and are some of the oldest ecosystems on Earth. Coralline structures protect coastlines from storms, maintain high diversity of marine life, and provide nurseries for marine species. Coral reefs play a role in carbon cycling through high rates of organic carbon metabolism and calcification. Coral reefs provide fisheries habitat that are the sole protein source for humans on remote islands. Reefs respond immediately to environmental change and therefore are considered "canaries" of the oceans. However, the world's reefs are in peril: they have shrunk 10-50% from their historical extent due to climate change and anthropogenic activity. An important contribution to coral reef research is improved spectral distinction of reef species' health where anthropogenic activity and climate change impacts are high. Relatively little is known concerning the spectral properties of coral or how coral structures reflect and transmit light. New insights into optical processes of corals under stressed conditions can lead to improved interpretation of airborne and satellite data and forecasting of immediate or long-term impacts of events such as bleaching and disease in coral. We are investigating the spatial and spectral resolution required to detect remotely changes in reef health by coupling spectral analysis of in situ spectra and airborne spectral data with a new radiative transfer model called CorMOD2. Challenges include light attenuation by the water column, atmospheric scattering, and scattering caused by the coral themselves that confound the spectral signal. In CorMOD2, input coral reflectance measurements produce modeled absorption through an inversion at each visible wavelength. The first model development phase of CorMOD2 imposes a scattering baseline that is constant regardless of coral condition, and further specifies that coral is optically thick. Evolution of CorMOD2 is towards a coral-specific radiative transfer model that includes coral biochemical concentrations, specific absorptivities of coral components, and transmission measurements from coral surfaces.
UR: http://geo.arc.nasa.gov/sge/coral-health/
DE: 1600 GLOBAL CHANGE (New category)
DE: 1640 Remote sensing
DE: 4815 Ecosystems, structure and dynamics
DE: 4847 Optics
DE: 4853 Photosynthesis
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting