Automated HCl laser monitor for long term and flight deployments

TECHNICAL ABSTRACT: Tropospheric oxidation capacity is dominated by HOx photochemistry, however halogen atoms and oxides significantly affect these chemical cycles. A sensitive and robust measurement of gaseous HCl is critically important to improve our understanding of halogen chemistry and its impacts on the spatial and temporal oxidation capacity of the atmosphere. In Phase I, we met all of our goals. We demonstrated a novel trace gas monitor that can sensitively (15 ppt noise at 1 Hz) and continuously monitor HCl without inlet artifacts. Our patented active passivation technique was extended from HNO3 to HCl, enabling HCl sampling with minimal surface interactions despite its stickiness. During Phase II we will improve the HCl monitor to provide more stable flight operation, develop an inlet switching system to measure reactive chlorine (ClNO2 and Cl2) and deploy the instrument for extended testing at a field site that is expected to show halogen photochemistry.SUMMARY OF ANTICIPATED RESULTS: The proposed instrument will be invaluable to the research market, governments agencies and academic institutions that research halogen cycling. Additional commercial opportunities exist in industrial fence line monitoring. The effort invested to make the instrument autonomous and flight ready will improve all of our trace gas monitors and will increase sales; almost all users would prefer an instrument that requires little or no user intervention and training