Novel instrumentation will be developed to measure the fluxes of trace gases between the atmosphere and the biosphere. The measurement systems, based on disjunct eddy flux methods, will be applicable to both tower based and airborne platforms. A complete airborne flux system will be maintained at Purdue University and made available to the biosphere/atmosphere science community. The technology will also be made available for duplication for different applications. The Disjunct Eddy Sampler (DES) will be coupled with an Fourier-Transform Infrared (FTIR) system capable of quantifying stable carbon isotope ratios. These measurements provide a means to partition the net ecosystem exchange of carbon dioxide into its gross components, photosynthetic uptake by vegetation and respiratory emissions by plants and soils. The DES system will also be employed to quantify fluxes of volatile organic compounds (VOCs) by combining it with a proton transfer reaction mass spectrometer (PTR-MS). Emphasis in this application will be in determining landscape scale fluxes. The third application area will be to couple the DES with nitrogen detectors for determination of deposition rates of atmospheric nitrogen containing species.
The development of this instrumentation will provide undergraduate and graduate research training opportunities. All team members are participants in the NSF IGERT program at the University of Michigan Biological Station and intend to involve IGERT students in this project.
Scientifically, the broader impact of this work will be in the area of biosphere-atmosphere exchange which is an integral part of all biogeochemical cycles. The determination of accurate transfer rates for inorganic and organic species between terrestrial and atmospheric reservoirs is a critically important need to enable reliable prediction of the future state of global climate and the oxidative capacity of the atmosphere.
