Measurements of landscape-scale CO ₂ fluxes at two ameriflux sites using a new vertical profiling method

CO ₂ is the most important greenhouse gas and its modulation by the biosphere is of fundamental importance to our understanding of global climate change. A new technique for vertical profiling of CO ₂ and meteorological parameters from the ground to 3 km was proposed. Vertical profiling of CO ₂ mixing ratios allowed estimates of landscape-scale fluxes characteristic of ≈ 100 sq km of an ecosystem. The method made use of a powered parachute as a platform and a new Tedlar™ bag air sampling technique. Air samples were returned to the ground where measurements of CO ₂ mixing ratios were made with high precision (≤ 0.1%) and accuracy (≤ 0.1%) using a conventional CO ₂ analyzer. Laboratory studies that characterize the accuracy and precision of the bag sampling technique as well as diffusion through the Tedlar™ bag wall were described. The technique was in field studies near two Ameriflux sites and the data used to calculate fluxes. This is an abstract of a paper originally presented at the 225th ACS National Meeting (New Orleans, LA 3/23-27/2003).