HR: 16:25h
AN: C54A-02 INVITED     [Abstracts]
TI: Studies of the distribution and mean residence times of freshwater in the Arctic Ocean using stable isotopes of water and tritium/He-3
AU: * Peter, S
EM: schlosser@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Rt 9W , Palisades, NY 10964-8000 United States
AU: * Peter, S
EM: schlosser@ldeo.columbia.edu
AF: Department of Earth and Environmental Engineering, Columbia University, New York City, NY 10027 United States
AU: Newton, B
EM: bnewton@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Rt 9W , Palisades, NY 10964-8000 United States
AU: Ekwurzel, B
EM: ekwurzel@hwr.arizona.edu
AF: University of Arizona, University of Arizona, Tucson, Az 85721-0011 United States
AU: Spieler, A
EM: spieler@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Rt 9W , Palisades, NY 10964-8000 United States
AB: Arctic freshwater plays a major role in determining the stratification of the water column within the Arctic Ocean, the Nordic seas and parts of the northernmost North Atlantic. Variability in freshwater storage and export from the Arctic Ocean to the formation regions of deep water in the Nordic seas and the North Atlantic contributes to variability in the preconditioning of surface waters that feed deep convection; as well as to salinity variations in large water bodies found in the Nordic seas and the North Atlantic. Thus, knowledge of the Arctic freshwater balance is a precondition for full description and understanding of the driving forces behind deep water formation and its variability in the Nordic seas and the northern North Atlantic. Since the early 1980's stable isotopes of water have been used to separate the individual components contributing to the freshwater balance of the Arctic Ocean. Additionally, transient tracers such as tritium and its decay product, He-3 have been used to estimate the mean residence times of the freshwater stored in the surface layers of the Arctic Ocean. Here we present stable isotope sections and isopycnal distributions and use them, together with nutrient data, to separate freshwater contributed to the upper waters of the Arctic Ocean by meteoric water (mainly river runoff), Pacific inflow through Bering Strait, and sea ice meltwater. Limited repeat sections are used to study temporal variability in the freshwater distribution. Additionally, we apply tritium/He-3 ages to estimate the mean residence times of the freshwater stored in the upper layers of the Arctic Ocean. Finally, we compare the observed freshwater components to model simulations of a (varying) freshwater distribution in the Arctic Ocean.
DE: 4808 Chemical tracers
DE: 4820 Gases
DE: 4870 Stable isotopes
DE: 4532 General circulation
DE: 1836 Hydrologic budget (1655)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting