© Author(s) 2009. This work is distributed under the Creative Commons Attribution 3.0 License. Atmospheric Chemistry and Physics

Abstract. Long term methane flux measurements have been mostly performed with plant or soil enclosure techniques on specific components of an ecosystem. New fast response methane analyzers make it possible to use the eddy covari-ance (EC) technique instead. The EC technique is advanta-geous because it allows continuous flux measurements inte-grating over a larger and more representative area including the complete ecosystem, and allows fluxes to be observed as environmental conditions change naturally without distur-bance. We deployed the closed-path Fast Methane analyzer (FMA) from Los Gatos Research Ltd and demonstrate its performance for EC measurements at a Ponderosa pine plan-tation at the Blodgett Forest site in central California. The fluctuations of the CH4 concentration measured at 10 Hz ap-pear to be small and their standard deviation is comparable t