Novel Ultrasensitive Instrumentation for Trace Gas Measurements in the Field

72855-The understanding of atmospheric chemistry and pollution transport in the troposphere, on large and small spatial scales, is limited by the availability of reliable, sensitive, and accurate instrumentation that is easy to use and yields rapid, real-time results. This project will develop a novel, compact, and rugged instrument that sensitively and accurately measures the concentrations of important atmospheric trace gases (NO, NO2, NO3, N2O, CO) and the fluxes of N2O and CO. The instrument, based on a novel technology called Off-Axis Integrated Cavity Output Spectroscopy (ICOS) and on state-of-the-art diode lasers and quantum-cascade lasers, will be easy to use and will provide real-time measurements in the field and on board aircraft. Phase I designed, built, and tested an Off-Axis ICOS instrument using three diode lasers and a quantum cascade laser, to conduct measurements of the target species (NO2, NO3, N2O5, CO, N2O), based on absorption in the visible and infrared regions. By performing measurements on calibrated gas mixtures, the accuracy, precision and sensitivity of the instrument was established. A Phase II instrument, capable of operation in the field and on-board aircraft, was designed, and a detailed estimate of the cost of building and selling the instruments, was determined. Phase II will develop and test advanced prototype multi-gas analyzers capable of simultaneous measurements of NO2, NO3, N2O5, CO and N2O in the laboratory, in the field, and on an airplane. In addition, the instrument will be deployed in the Arctic for autonomous field measurements. Commercial Applications and Other Benefits as described by awardee: The instrumentation should find application in atmospheric studies, medical diagnostics to detect common diseases, homeland security, and the monitoring and control of several industrial processes.