PROGRAM TITLE: High Latitude Dynamics, Arctic Sediment History ACTIVITY STREAM: Process Studies, Data SCIENCE ELEMENT:Earth Systems History DEPARTMENT OF DEFENSE OFFICE OF NAVAL RESEARCH (ONR) SCIENTIFIC MERIT: Arctic Past Climates and Sea Levels; geological and historical records document the natural variability of the physical environment, climate, and ecosystems on time scales from inter annual to millions of years. The record of these important events, changes , and focusing processes is contained in the marine sediments of the Arctic Ocean and the Marginal Seas (AOMS). Once deciphered, this paleo environmental and paleoclimate record will provide substantial information about the Earth's history for much of the past 90 million years, and describe the forcing function. ONR has a strong track record in Arctic research, especially acoustics stratigraphy, physical properties of sediments, and sedimentary processes. These programs relate directly to stated Navy needs in acoustic ASW and very conveniently match the goals of the USGCRP. For example, from the stratigraphy and the contained paleoceanography record, key climate questions that can be addressed are: -- characterization of the Arctic deep sea paleoenvironment; timing/characteristics of initial climate cooling and glaciation; timing, magnitude, and periodicity of high amplitude late Cenozoic climate oscillations which can occur within a decade; -- sea level fluctuation and resultant ice sheet movement; and paleoceanographic and paleontologic fauna and flora response to climate change. These goals evolved from several workshops, including: -- Arctic Oceans Research Strategy, 1990 -- Strategy for Integrated U.S. Arctic Research Programs, 1991 -- The Arctic Ocean Record: Key to Global Change (Initial Science Plan), 1992 -- PAGES Š Proposed Implementation Plans, 1992 STAKEHOLDERS: The paleoclimatic research effort will fall under the umbrella of PAGES (Past Global Changes Project, IGBP Core Program) and the Nansen Arctic Drilling Program, as well as US Agency Sites Program of USGS and CGS. ONR funded scientists have the lead role in the 1995 deep Arctic penetration cruise with the LOUIE ST. LAURANT (Canada), POLARSTERN (FRG), and POLAR SEA (USA). POLARSTERN will be equipped with a modified super corer (30 meters), and POLAR SEA will have WHOI box cores, hydraulic Bender cores (waterŠsediment fluff layer) and piston corer. In FY 96, cores will be analyzed on an international, multi disciplinary basis to address key questions described above. International plans are in place for drilling selected with a decadal time resolution in FY96. POLICY RELEVANCE: This research supports an IGBP Core Project (PAGES) and was identified as priority research issue by the Interagency Arctic Research Program. Past abrupt climate changes are documented in the deep ocean sediment record; this internationally partnered research will generate new data to describe past abrupt changes and the larger climate trends. PROGRAM CONTACT:Dr. G. Leonard Johnson, ONR Code 325, 800 N Quincy Street, Arlington, VA 22217-5000, (703) 696 4118