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Kara S ea freshwater transport through V ilkitsky S trait: Variability, forcing, and further pathways toward the western A rctic O cean from a model and observations
Author(s) -
Janout Markus A.,
Aksenov Yevgeny,
Hölemann Jens A.,
Rabe Benjamin,
Schauer Ursula,
Polyakov Igor V.,
Bacon Sheldon,
Coward Andrew C.,
Karcher Michael,
Lenn YuengDjern,
Kassens Heidemarie,
Timokhov Leonid
Publication year - 2015
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2014jc010635
Subject(s) - oceanography , baroclinity , hydrography , outflow , arctic , current (fluid) , geology , forcing (mathematics) , ocean current , climatology , environmental science
Siberian river water is a first‐order contribution to the Arctic freshwater budget, with the Ob, Yenisey, and Lena supplying nearly half of the total surface freshwater flux. However, few details are known regarding where, when, and how the freshwater transverses the vast Siberian shelf seas. This paper investigates the mechanism, variability, and pathways of the fresh Kara Sea outflow through Vilkitsky Strait toward the Laptev Sea. We utilize a high‐resolution ocean model and recent shipboard observations to characterize the freshwater‐laden Vilkitsky Strait Current (VSC), and shed new light on the little‐studied region between the Kara and Laptev Seas, characterized by harsh ice conditions, contrasting water masses, straits, and a large submarine canyon. The VSC is 10–20 km wide, surface intensified, and varies seasonally (maximum from August to March) and interannually. Average freshwater (volume) transport is 500 ± 120 km 3 a −1 (0.53 ± 0.08 Sv), with a baroclinic flow contribution of 50–90%. Interannual transport variability is explained by a storage‐release mechanism, where blocking‐favorable summer winds hamper the outflow and cause accumulation of freshwater in the Kara Sea. The year following a blocking event is characterized by enhanced transports driven by a baroclinic flow along the coast that is set up by increased freshwater volumes. Eventually, the VSC merges with a slope current and provides a major pathway for Eurasian river water toward the western Arctic along the Eurasian continental slope. Kara (and Laptev) Sea freshwater transport is not correlated with the Arctic Oscillation, but rather driven by regional summer pressure patterns.