12.4
Relationship between CO2 Flux and CO2 Concentration at a Boreal Forest
D. Chan, MSC, Toronto, ON, Canada; and K. Higuchi, A. Shashkov, D. Worthy, J. Chen, J. Liu, and C. W. Yuen
On the diurnal time scale, eddy correlation CO2 flux measurements have footprints of about 1 km2, while CO2 concentration measurements have footprints of the order of 1000 km2. Therefore it is necessary to understand the relationship between the CO2 flux and concentration measurements to scale up the small scale flux measurements to the regional scale concentration measurements. In this study, we examined the flux-concentration relationship in the atmospheric boundary layer (ABL) at a boreal forest site in Saskatchewan, Canada; using a combination of flux measurements, aircraft profile concentration measurements, and coupled biosphere-atmosphere model. The results suggest that in the night time with typically low wind speed, the CO2 concentration in the shallow stably stratified ABL is dominated by the local CO2 flux. While the daytime CO2 concentration in the deep well-mixed ABL is strongly influenced by atmospheric transport, and the atmospheric transport is driven by mesoscale and synoptic scale processes. Therefore, understanding of the mesoscale and synoptic scale atmosphere-biosphere interaction is important in the flux-concentration relationship. .
Session 12, Carbon dioxide exchange 3
Thursday, 26 August 2004, 1:30 PM-4:30 PM
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