This project will conduct comprehensive biogenic volatile organic compound (BVOC) emission measurements for an Arctic tundra ecosystem with the goals of understanding the impact of BVOC emissions on atmospheric chemistry and the effects of global change factors in the Arctic on BVOC emissions. The project has three experimental components which span spatial and temporal scales to achieve these goals. (1) A comprehensive species characterization campaign will identify Arctic plants that are important BVOC emitters. (2) An intensive field campaign will use micrometeorological techniques to measure isoprene and ozone fluxes above a tundra ecosystem near the Toolik Field Station in collaboration with an on-going project studying ecosystem carbon balance, and these data will be used with a photochemical model to study impacts on atmospheric chemistry. (3) Leaf-level and chamber enclosure measurements at existing global change factor manipulation sites will allow for predictions of how ecosystem BVOC emissions will change in the future.
The project will bring two underrepresented minority students, one from the Central Valley in California and the other from urban Chicago, to the Toolik Field Station in Alaska for undergraduate research. The principal investigator has an on-going collaboration with the Peggy Notebaert Nature Museum of the Chicago Academy of Sciences to communicate global climate change themes to high school teachers, and he will incorporate the field experiences from this proposal into his teaching materials. In addition, results of the research will be communicated to the broader scientific community through publication in peer-reviewed journals and presentations at meetings where these cross-disciplinary research results can be shared.
Funding related to this project supported two field trips to the Toolik Lake field station to make observations regarding the flux of biogenic volatile organic compounds (BVOC) from the Arctic tundra to the atmosphere. The principal investigator and one graduate student traveled to Toolik Lake, located approximately 100 miles south of the Arctic Ocean, for several weeks during June and July of 2010 and 2011. This specific work is a collaboration between scientists at California State University Sacramento (CSUS) in Sacramento, California, and scientists at DePaul University in Chicago, Illinois. Ecosystem level flux measurements of isoprene show that the Arctic tundra is a significant source of isoprene and reactive carbon to the Arctic atmosphere. A simple atmospheric model incorporating isoprene's chemistry suggests that oxidation chemistry within the Arctic tundra's boundary layer would be doubled if isoprene emissions were not present at measured flux rates. Leaf level measurements indicate that willow (S. pulchra) is the dominant isoprene emitter on the Arctic tundra. Other data collected during the field campaign indicate that levels of other BVOC emissions are quite low. No significant BVOC emissions were found from individual plant species. Ground enclosures showed that some species of moss may be a significant source of isoprene to the Arctic atmosphere. Very little data exists regarding emissions of BVOCs from Arctic vegetation. These measurements demonstrate that BVOC emissions should be included when considering the chemistry of the Arctic atmosphere.
