Eddy covariance imaging of diffuse volcanic CO sub(2) emissions at Mammoth Mountain, CA, USA

Use of eddy covariance (EC) techniques to map the spatial distribution of diffuse volcanic CO sub(2) fluxes and quantify CO sub(2) emission rate was tested at the Horseshoe Lake tree-kill area on Mammoth Mountain, California, USA. EC measurements of CO sub(2) flux were made during September-October 2010 and ranged from 85 to 1,766 gm super(-2) day super(-1). Comparative maps of soil CO sub(2) flux were simulated and CO sub(2) emission rates estimated from three accumulation chamber (AC) CO sub(2) flux surveys. Least-squares inversion of measured eddy covariance CO sub(2) fluxes and corresponding modeled source weight functions recovered 58-77% of the CO sub(2) emission rates estimated based on simulated AC soil CO sub(2) fluxes. Spatial distributions of modeled surface CO sub(2) fluxes based on EC and AC observations showed moderate to good correspondence (R super(2)=0.36 to 0.70). Results provide a framework for automated monitoring of volcanic CO sub(2) emissions over relatively large areas.