9400256 Lewin Research supported by this grant is under the auspices of the Arctic Systems Science (ARCSS) Global Change Research Program and is jointly sponsored by the Division of Ocean Sciences and the Office of Polar Programs. The research will be centered around a unique and intensive, multidisciplinary research expedition to parts of the Arctic Ocean that have never been extensively studied. The 1994 U.S./Canada Arctic Ocean Section is a collaborative effort with Canada that will involve approximately 60 scientists on a Canadian and a U.S. icebreaker during summer 1994. NSF-funded projects will focus on hydrography, biology, paleo-, and sea-ice studies. Data collected will be amongst the first ever from several regions of the Arctic Ocean and will be highly relevant to improving our understanding of how the Arctic is an indicator ofchanging global climate conditions and how it affects the physical, chemical, and biological features of the more temperate oceans and regions. This collaborative research effort between investigators at the Univ. of Washington and Oregon State University represents a critical component of the AOS biology program. The project will measure standing stocks and production rates of planktonic and ice-algae. These parameters will be determined along the cruise track and will be the first such measurements from parts of the Arctic Ocean. In addition to phytoplankton abundances, primary production, new and regenerated nitrogen production, mesozooplankton stocks, and spatial distribution of particulate organic matter and dissolved organic matter will be determined. These studies will be used to evaluate the magnitude of Arctic basin productivity and the major pathways for the flow of carbon. This work in conjunction with other collaborative efforts will lead to a greater understanding of the role of primary production, fate of photosynthetically fixed carbon, and the relative importance of autotrophic and heterotrophic processes in transforming and transpo rting particulate and dissolved forms of carbon to, within, and from the Arctic Ocean system. ***