Formaldehyde and Hydrogen Peroxide Instrument for Flight Based Measurements

Hydrogen peroxide formation represents a loss of gas phase HOx and results in the transfer of atmospheric oxidative capacity to the liquid phase. Measurements of formaldehyde and H2O2 are vital to fully elucidate the atmospheric mechanisms associated with ozone formation and the formation of inorganic and secondary organic aerosol throughout the atmosphere. Tunable infrared differential absorption spectroscopy allows selective and sensitive measurements of many low molecular weight trace gas species. The ability to detect HCHO from an aircraft platform using pulsed quantum cascade lasers has been demonstrated (300 pptv Hz-¿. This proposal will apply these methods to the detection of H2O2. A novel approach to increase sensitivity is proposed by developing a continuous wave light source with an improved linewidth. Realization of the improvements proposed in this research program will lead to a single instrumentation package with detection sensitivity of 125 pptv Hz ¿ ¿ for H2O2 and 50 pptv Hz-¿ for formaldehyde.