RADONMEAS

Radon Measurements of Atmospheric Mixing (RAMIX)

1 November 2006 - 31 March 2008

Lead Scientist: Marc Fischer

Observatory: SGP (Southern Great Plains)

Uncertainty in vertical mixing between the surface layer, boundary layer, and free troposphere leads to significant uncertainty in determining regional carbon exchange from measurements of atmospheric CO2 mixing ratios. Radon (222Rn) provides a valuable tracer of atmospheric mixing because it is emitted relatively ubiquitously from the land surface and has a short enough half life (3.8 days) to allow characterization of mixing processes based on vertical profile measurements. In this collaborative IOP with NOAA-CMDL, we measured atmospheric 222Rn concentrations from the SGP 60 m tower with the objectives of 1) estimating the time averaged atmospheric mixing between the different atmospheric layers and during selected convective events, and 2) using the measured mixing rates to estimate regional CO2 exchange. To accomplish these objectives, the continuous tower-based measurements were combined with planned airborne concentration 222Rn measurements and surface 222Rn flux measurements and modeling (separately supported by the ARM/LBNL Carbon Project and NOAA-CMDL).