Regional Carbon Fluxes and Atmospheric Carbon Dynamics in the Southern Great Plains during the 2007 Mid Continent Intensive of NACP

In June 2007, an intensive regional campaign will take place in the Southern Great Plains (SGP) to estimate land-atmosphere exchanges of CO2, water, and energy at 1 to 100 km scales. The primary goals of this North American Carbon Program (NACP) campaign are to evaluate top-down and bottom-up estimates of regional fluxes and to understand the influence of moisture gradients, surface heterogeneity, and atmospheric transport patterns on these fluxes (and their estimation). The work will be integrated with the Cloud and Land Surface Interaction Campaign (CLASIC), centered on the US DOE Atmospheric Radiation Measurement Program SGP region. CLASIC will focus on interactions among the land surface, convective boundary layer, and cumulus clouds, and will utilize an array of atmospheric measurements. Carbon and meteorological data streams and logistical resources will be available to other NACP researchers. Carbon flux and concentration data will be collected from tower and airborne platforms. Eddy flux towers will be deployed in the four major land cover types, distributed over the region's SE to NW precipitation gradient. In addition, CO2, water, and energy fluxes will be observed with the Duke Helicopter Observation Platform (HOP) at various heights in the boundary layer, including in the surface layer (the few meters near the surface). Two aircraft will carry precise CO2 measurement systems and NOAA12-flask packages for carbon cycle gases and isotopes. Continuous CO2 and CO concentrations, NOAA flasks, and isotope diel flasks (14C, 13C, and 18O) will also be collected from a centrally located 60 m tower. Flights are planned to constrain simple boundary layer budget models and to conduct Lagrangian air mass following experiments. A distributed model of land surface fluxes will be run off line and coupled to MM5 with tracer capability. In addition to characterizing the influence of the land surface on the atmosphere, the aircraft data (in combination with observations of atmospheric dynamics) will provide a very well characterized southern boundary condition to the Mid-Continent Intensive.