9415789 WINDOM Processes affecting material transport to the oceans from Arctic- Subarctic Watersheds, from direct groundwater discharge and through Lagoon Systems A number of gaps exist in the understanding of biogeochemical processes associated with the transport of material across the land-sea boundary. Among these gaps are lack of data on: 1) small watersheds of different morphoclimatic zones and their ability/efficiency, relative to larger watersheds, to transport materials to the oceans, 2) transport of material through lagoonal estuarine systems, the mixing rates of which are slow and the mixing zones large, and 3) inputs of material to coastal waters in groundwater. Research is proposed to address these gaps through investigations on three types of under-studied systems with the following objectives: A) To obtain a better understanding of products resulting from arctic-subarctic weathering, the fate of these materials (primary trace elements) in the freshwater-seawater mixing zone and relative contribution of fluxes to the ocean from smaller rivers of this morphoclimatic zone. These studies will be carried out in the Anadyr river-estuary system in Northeastern Russia. B) To identify the major biogeochemical interactions that control trace element fluxes through a lagoonal estuary, taking advantage of the slow mixing rate/long residence times of materials in such systems to obtain better resolution of solute-master variable relationships during mixing in the low salinity region. The Patos Lagoons, in Southern Brazil will provide the field site for these investigators. C) To determine the composition and concentrations of subterranean weathering products associated with the Floridan Aquifer and to investigate biogeochemical processes that influence the fate of trace elements upon entering the marine environment. Freshwater springs, which discharge directly into coastal waters of the West Florida shelf, and the adjacent coastal waters will pr ovide the site for these studies.
