Circulation in the northwest Laptev Sea in the eastern Arctic Ocean: Crossroads between Siberian River water, Atlantic water and polynya-formed dense water
2017
This paper investigates new observations from the poorly understood region between the Kara
and Laptev Seas in the Eastern Arctic Ocean. We discuss relevant circulation features including riverine
freshwater, Atlantic-derived water, and polynya-formed dense water, emphasize Vilkitsky Strait (VS) as an
important Kara Sea gateway, and analyze the role of the adjacent 250 km-long submarine Vilkitsky Trough
(VT) for the Arctic boundary current. Expeditions in 2013 and 2014 operated closely spaced hydrographic
transects and 1 year-long oceanographic mooring near VT’s southern slope, and found persistent annually
averaged flow of 0.2 m s21 toward the Nansen Basin. The flow is nearly barotropic from winter through
early summer and becomes surface intensified with maximum velocities of 0.35 m s21 from August to
October. Thermal wind shear is maximal above the southern flank at 30 m depth, in agreement with
basinward flow above VT’s southern slope. The subsurface features a steep front separating warm (–0.58C)
Atlantic-derived waters in central VT from cold (<–1.58C) shelf waters, which episodically migrates across
the trough indicated by current reversals and temperature fluctuations. Shelf-transformed waters dominate
above VT’s slope, measuring near-freezing temperatures throughout the water column at salinities of
34–35. These dense waters are vigorously advected toward the Eurasian Basin and characterize VT as a
conduit for near-freezing waters that could potentially supply the Arctic Ocean’s lower halocline, cool
Atlantic water, and ventilate the deeper Arctic Ocean. Our observations from the northwest Laptev Sea
highlight a topographically complex region with swift currents, several water masses, narrow fronts,
polynyas, and topographically channeled storms.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
59
References
11
Citations
NaN
KQI