This award supports the development field-capable instrumentation capable of high frequency (10 Hz) sampling of isotopic fluxes of carbon dioxide (12CO2 and 13CO2). Study of atmospheric gases, atmospheric chemistry, and global carbon cycle would greatly benefit from the availability of instrumentation capable of accurate, precise, and high-speed measurements of isotopic fluxes. The instrumentation will enable long-term measurement of net ecosystem exchange (NEE) of carbon with concurrent, real-time partitioning of NEE into its photosynthetic and respiratory components when coupled to existing high frequency eddy covariance (EC) micrometeorological techniques. The interdisciplinary development team includes a physicist expert in use of lasers in stable isotope analysis, an ecosystem modeler with extensive field experience, and a plant ecophysiologist specializing in leaf-level photosynthetic gas exchange. The team will expand the capabilities of a new laser-based stable carbon isotope analysis system (acronym LARA) and to perform validating field experiments. The LARA technique is based on the existence of large isotope shifts in molecular spectra, the use of fixed frequency isotopic lasers and sensitive detection via the laser optogalvanic effect. The effort will involve the participation of post doctoral associates, graduate and undergraduate students of physics, biological and environmental science and high school interns who will be trained in optical science, measurement science, biometeorology, environmental physics and ecology. Undergraduate and graduate courses taught by the faculty participants will include trips to the field site and exercises utilizing data gathered during the project.
