The first part of this talk contains an overview of two projects focused on measurements of tropospheric trace gases in the marine boundary layer. Both studies rely on the Differential Optical Absorption Spectroscopy (DOAS) measurement technique and the development of low noise/high sensitivity instrumentation to detect halogen oxides and volatile organic compounds (VOCs) at volume mixing ratios <10 pptv. The first of these studies utilizes a ground-based passive remote sensing instrument that was developed for measuring bromine monoxide (BrO) and iodine monoxide (IO) in order to investigate the potential role of halogen species in atmospheric mercury oxidation at mid-latitudes. In the second of these studies, a cavity enhanced DOAS instrument was developed to measure glyoxal (the smallest alpha-dicarbonyl) fluxes over the open ocean to aid in our understanding of potential sources of VOCs in a pristine remote environment.
The second part of this talk details a project that is currently underway which seeks to expand the spectroscopic measurement applications of frequency comb instrumentation to open path field measurements of methane. The proposed project includes the development of a fieldable dual frequency comb instrument capable of measuring trace enhancements of methane (~1 ppbv on top of 2 ppmv background) which used in conjunction with atmospheric modeling and inversion techniques will allow the instrument to locate and size small methane leaks on oil and gas operation sites.