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| Titel |
Freshwater sources, distribution, and temporal variability in the Canadian Basin of the Arctic Ocean: Results from US Arctic GEOTRACES 2015 and comparison with 1994 and 2005 sections |
| VerfasserIn |
Angelica Pasqualini, Peter Schlosser, Robert Newton, Tobias Koffman, William M. Smethie |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250146319
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| Publikation (Nr.) |
 EGU/EGU2017-10339.pdf |
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| Zusammenfassung |
| We present and discuss freshwater components calculated from measurements of stable
isotopes of water, salinity and nutrients along the US Arctic Geotraces section completed
across the Canadian Basin of the Arctic Ocean in 2015. Samples were collected at 66
CTD/rosette stations (22 GEOTRACES and 44 repeat hydrography program) along
two transects extending from the continental shelf to the North Pole roughly along
longitudes 180˚ W and 150˚ W. Stable isotope measurements (H218O/H216O and
2HHO/H2O ratios) were performed on 1020 water samples covering the entire water
column at GEOTRACES stations and the upper 500 m at Repeat Hydrography
stations.
In combination with salinity and nutrient data, the oxygen isotope ratios were
used to calculate the individual freshwater components for the upper Arctic Ocean
(mixed layer through Atlantic Water layer) including Pacific Water, Meteoric Water
and Sea Ice Meltwater. The fractions are integrated through the water column to
obtain inventories of the individual freshwater components. The water column is
characterized by sea ice meltwater and meteoric water in the upper 50 to 100 meters. Below
this layer Pacific water dominates the freshwater budget along the 2015 Arctic
GEOTRACES section. The water column below ca. 100 meters also carries the signal of
brine rejection during sea ice formation, reflected in negative sea ice meltwater
fractions.
The 2015 results are placed into the context of the 1994 and 2005 Arctic Ocean Sections
and discussed in the framework of the processes governing the dynamics of the upper layers
in the Arctic Ocean. |
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