Aircraft-derived regional scale CO2 fluxes from vegetated drained thaw-lake basins and interstitial tundra on the Arctic Coastal Plain of Alaska

摘要

The landscape surface of the Barrow Peninsula of Alaska is a mosaic of small ponds, thaw lakes, different aged vegetated drained thaw-lake basins (VDTLBs), and interstitial tundra which have been dynamically formed by both short-and long-term processes. We used a combination of tower-and aircraft-based eddy covariance measurements to characterize the spatial and temporal patterns of CO2, latent, and sensible heat fluxes along with MODIS NDVI, and were able to scale the aircraft-based CO2 fluxes to the 1802km(2) Barrow Peninsula region. During typical 2006 summer conditions, the midday hourly CO2 flux over the region was -2.04 x 10(5) kgCO(2)h(-1). The CO2 fluxes among the interstitial tundra, Ancient, and Old VDTLBs, as well as between the Medium and Young VDTLBs were not significantly different. Combined, the interstitial tundra and Old and Ancient VDTLBs represent similar to 67% of the Barrow Peninsula surface area, accounting for similar to 59% of the regional flux signal. Although the Medium and Young VDTLBs represent similar to 11% of the surface area, they account for a large portion, similar to 35%, of the total regional flux. The remaining similar to 22% of the surface area are lakes and contributed the remaining similar to 6% of the total regional flux. Previous studies treated vegetated areas of the region as a single surface type with measurements from a few study sites; doing so could underestimate the regional flux by similar to 22%. Here, we demonstrate that aircraft-based systems have the ability to cover large spatial scales while measuring the turbulent fluxes across a number of surfaces and combined with ground-and satellite-based measurements provide a valuable tool for both scaling and validation of regional-scale fluxes.