HR: 17:00h
AN: C54A-04 [Abstracts]
TI: The Freshwater Flux to the Arctic via the Bering Strait
AU: * Woodgate, R A
EM: woodgate@apl.washington.edu
AF: Applied Physics Laboratory,
University of Washington, 1013 NE 40th Street, Seattle, WA 98105
United States
AU: Aagaard, K
EM: aagaard@apl.washington.edu
AF: Applied Physics Laboratory,
University of Washington, 1013 NE 40th Street, Seattle, WA 98105
United States
AB:
The freshwater flux to the Arctic via the Bering Strait has
long been estimated at 1670 km$^{3}$/yr, based on an annual
transport estimate of 0.8 Sv and a near-bottom mean salinity
of 32.5 psu, referenced to 34.8 psu (Aagaard & Carmack, 1989).
This is almost a third of the total freshwater input to the
Arctic Ocean.
We present 3 substantial modifications to this estimate.
1) The Alaskan Coastal Current - mooring data, ship data, and
satellite imagery indicate a warm, fresh, generally coastally trapped current is present in the strait for many months of the
year. The first year-round in situ measurements of the ca. 10 km wide current, indicate it alone may carry an additional ca.
400 km$^{3}$/yr of
freshwater into the Arctic Ocean.
2) Effects of stratification - summer CTD sections suggest
near-bottom measurements overestimate the mean salinity
by order 0.5 psu, resulting in a ca. 300 km$^{3}$/yr increase in the freshwater flux estimate.
3) Interannual variability - a 13-year time-series of
near-bottom moored measurements in the Bering Strait
indicates the interannual variability in mean salinity is
ca. 0.6 psu, resulting in a variability in the
freshwater flux of order 400 km$^{3}$/yr.
Combined, these measurements indicate that the prior
estimate of 1670 km$^{3}$/yr may be underestimating the
actual freshwater flux through the Bering Strait by
order 50%.
UR: http://psc.apl.washington.edu/BeringStrait.html
DE: 4207 Arctic and Antarctic oceanography
DE: 4215 Climate and interannual variability (3309)
DE: 4223 Descriptive and regional oceanography
DE: 4532 General circulation
DE: 1836 Hydrologic budget (1655)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting