9508333 Chapin A Doctoral Dissertation Award to the University of California Berkeley will support a project to determine the mechanisms by which different plant growth forms integrate to control water and energy balance at the ecosystem level in Arctic tundra on the Alaskan North Slope. This study is important because it will provide an explanation of how plant growth form properties can be scaled up to ecosystem level water and energy fluxes. The study will take place in conjunction with a larger Global Climate Change study that is examining the regional flux of greenhouse gases from the tundra. This project provides a unique opportunity to determine the role of plant growth habit on energy balances in the climatically sensitive Arctic tundra within the context of the regional output/uptake of greenhouse gases. The study amy provide new information on ecosystem response to climatically-induced changes of greenhouse gases. *** 9422292 Gawarkiewicz Investigators at the Woods Hole Oceanographic Institution will undertake research to increase the complexity of computer model simulations of the formation of dense high-salinity water that leaves the Arctic continental shelf and flows to the deep Arctic Ocean. The flows are capable of carring nutrients and sediments from the continental shelf to the deeper ocean and may play a major role in the transfer of heat between the atmosphere and deep ocean. Fluctations in the formation of the cross-shelf flow could affect the transfer of heat from warm deep water in the Arctic Ocean that is produced in the Atlantic Ocean. Heat from that warm deep flow controls the formation of sea ice in the climatically sensitive Arctic Ocean. The improved computer models will for the first time take into account the effects of coastal currents, topographic complexities, and water-mass stratification of the continental slopes so that the models may begin to approach real world conditions. The improved models are necessary to understand how the Arctic ocean-atmosphere-ice system operates to affect, and be affected by, global climates. *** ??
