Biogeochemical tracers in Arctic rivers: Linking the Pan-Arctic Watershed to the Arctic Ocean (PARTNERS) - NSF-Arctic System Science (2002 - 2007)
This NSF funded project was awarded to the Marine Biological Laboratory in Woods Hole and combines an international and multidisciplinary team of scientists to investigate the seasonal and annual variations in the discharge of the six largest Arctic rivers (Ob, Yenisey, Lena, Kolyma, Yukon, and Mackenzie).  Next to the seasonal changes in discharge of a variety of organic and inorganic compounds we want to identify and quantify tracers in the rivers that can be used to detect environmental changes in the rivers as well as throughout the Arctic Ocean. This is the first project to return real seasonal information from these high latitude rivers which have never been sampled during the low-flow winter season due to the harsh climate. My responsibilities in this project are to determine the concentrations of lignin phenols and carbohydrates in bulk DOM and DOM fractions harvested by ultrafiltration and solid phase extraction (SPE). I will also determine the optical properties of the river samples to develop a specific in situ fluorescence probe to be used in the Arctic Ocean.

Tracing biogeochemical fluxes and water mass exchanges on the Eurasian Shelves - NSF-Arctic Natural Sciences (2004-2007)

The Arctic ocean is characterized by lateral exchanges with the surrounding continents and other ocean basins. This has a major influence on water mass distribution and biogeochemical fluxes in the Arctic Ocean. During ice-breaker cruises we will investigate the exchange of DOM between the extended shelf and the open Arctic Ocean by combining the measurements of optical properties and dissolved organic constituents with other oceanographic tracers and volume transport estimates. For higher spatial resolution we employ an in situ fluorescence probe to trace the terrestrial component of DOM. Initial results suggest that a significant amount (20-50%) of the river discharge is exported from the Arctic Ocean in the East Greenland Current.  Central questions for the future include the role of sea ice formation for the horizontal and vertical distribution of water masses and DOM in the Arctic Ocean interior. A number of cruises on the ice breakers Polarstern and Oden (BERINGIA 2005) are planed for the summer/fall 2005 to the Canadian Archipelago and across the central Arctic Ocean to address shelf - basin exchanges. This project involves numerous collaborations with colleagues from the University of South Carolina, the University of Connecticut, the University of Washington, and the University of Texas, and the National Environmental Research Institute of Denmark. The crossing of the Arctic Ocean is a unique opportunity to enhance our understanding of the Arctic Ocean System. The Numerous collaborations will introduce a variety of newly developed methods to the Arctic Ocean for the first time.