PARENT SESSION
Poster Session # 5: GIS and Remote Sensing.
Monday, August 4 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.
SpecNet: Integrating optical remote sensing with ecosystem flux measurements at FLUXNET sites.
Gamon, John*,1, Rahman, Faiz2, Sims, Daniel1, Huemmrich, Karl3, Oechel, Walter4, 1 Center for Environmental Analysis (CEA-CREST), Los Angeles, CA2 Department of Geography, Muncie, IN3 Code 923.4, Greenbelt, MD4 Global Change Research Group, San Diego, CA
ABSTRACT- Ecosystem carbon flux is often measured by eddy covariance, providing temporally rich (but spatially poor) measurements of carbon and water vapor flux at selected terrestrial ecosystems. On the other hand, remote sensing provides a synoptic view of the world, yet has difficulty providing temporally continuous data at a scale that can be related to flux measurements. SpecNet (Spectral Network) is designed to better integrate optical remote sensing with ecosystem flux data at flux tower (FLUXNET) sites as a basis for cross-ecosystem analysis of carbon and water vapor flux. A unique feature of SpecNet is the provision of repeated optical sampling at a scale that closely matches that of the flux tower footprint. Here we report initial results comparing optical and flux data from several SpecNet sites, including Alaskan tundra, Californian chaparral, and deciduous forest. This combined analysis of optical and flux data reveals contrasting and dynamic ecosystem behavior that reflects underlying limitations to ecosystem productivity. For example, water limitations are apparent in both Arctic and chaparral ecosystems. Statistical analyses suggest optimal sampling and aggregation methods for optical and flux data that best reveal temporally changing flux patterns. These results demonstrate the complementary nature of optical and flux sampling, and provide a basis for improving remotely sensed estimates of carbon and water vapor flux from terrestrial ecosystems.
Key words: remote sensing, FLUXNET, ecosystem carbon flux, eddy covariance