PARENT SESSION
Oral Session #44: Global Change and Climate Change.
Presiding: C. Wessman
Tuesday, August 6. 1:00 PM to 4:45 PM. Grand Ballroom West, Radisson.

Statistically based assessment of aircraft CO₂ flux measurements and NDVI in Arctic Alaska .

Lin, Chii-Dean Joey^*,1, Oechel, Walter², Steffey, Duane¹, Zulueta, Rommel², Verfaille, Joe², Gamon, John³, ¹ Department of Mathematics & Computer Sciences, San Diego, CA² Global Change Research Group, San Diego, CA³ Department of Biology, Los Angeles, CA

ABSTRACT- Aircraft based measurements of net ecosystem CO₂ flux, reflectance, and microclimate were made on the North Slope of Alaska during the 2000 and 2001 growing seasons. These measurements were made at 10 meters above the surface over a N-S transect running from north of Barrow to south of Atqasuk, a distance of approximately 150 km. An east-west transect was also flown. Here we use statistical approaches to estimate the size and position of the aircraft footprint by optimizing the correlation between flux measurements and NDVI, after accounting for the effects of wind speed and direction. Additionally, we determine the optimal averaging interval for flux analysis, and the optimal pixel size for NDVI. We compare the results using the statistically determined footprint with that calculated using standard programs. Initial results indicate a high level of information in NDVI measured at approximately 100 m intervals in interpreting fluxes averaged at intervals of from 1-15 km.

KEY WORDS: Fluxes, Optimization, NDVI, Eddy Covariance