Intercomparison of Formaldehyde Measurements during BEACHON ROCS 2010

The BEACHON (Biosphere-hydrosphere-atmosphere-interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen) long term research initiative was established to shed light on sources, sinks and the atmospheric fate of organic aerosol and precursor gases. The BEACHON-Rocky mountain Organic Carbon Study (BEACHON-ROCS) focused on the biosphere-atmosphere exchange of reactive organic gases in a rural coniferous forest northwest of Colorado Springs, CO, during August 2010. Formaldehyde (HCHO) is an important tracer of VOC oxidation as it is formed during atmospheric oxidation of biogenic VOCs such as isoprene and other terpenes. Here we present measurements of formaldehyde conducted by two independent instruments, the Madison Fiber Laser Induced Flourescence (FILIF) Instrument and a Proton Transfer Reaction Time of Flight mass spectrometer (PTR-TOF-MS). Both instruments simultaneously measured HCHO concentrations at high temporal resolution potentially allowing for eddy covariance flux calculations. The comparison between FILIF and PTR-TOF-MS suggests generally good agreement.