Development of a Fourier-Transform Infrared Gas Analyzer to Measure Carbon Isotopes of CO2.

79737B Only half of the estimated carbon delivered to the atmosphere by human activities in the 1990s remains there. The "missing" carbon was absorbed by terrestrial ecosystems and oceans, thus mitigating human perturbations to the carbon cycle. Carbon isotopes play a central role in understanding this terrestrial carbon sink at a variety of scales, but instrumentation to directly measure carbon isotope fluxes is needed. To meet the needs of carbon scientists for field-deployable instrumentation, this project will design, manufacture, and market a fast-response, Fourier-transform, infrared gas analyzer for continuous, unattended eddy covariance measurements of isotopic carbon fluxes. Compared to present methods, the gas analyzer will be small, rugged, low power, and cost effective. Phase I will: (1) define the gas analyzer's required performance, (2) model its predicted performance, (3) complete a preliminary design, (4) build a lab prototype, and (5) test the lab prototype. Commercial Applications and other Benefits as described by the awardee: The gas analyzer¿s field deployment and comparative low cost should make isotopic measurements available to more carbon cycle scientists.