Variability and Redistribution of Heat in the Atlantic Water Boundary Current North of Svalbard


Contact
Markus.Janout [ at ] awi.de

Abstract

We quantify Atlantic Water heat loss north of Svalbard using year-long hydrographic and current records from three moorings deployed across the Svalbard Branch of the Atlantic Water boundary current in 2012–2013. The boundary current loses annually on average 16W m−2 during the eastward propagation along the upper continental slope. The largest vertical fluxes of >100W m−2 occur episodically in autumn and early winter. Episodes of sea ice imported from the north in November 2012 and February 2013 coincided with large ocean-to-ice heat fluxes, which effectively melted the ice and sustained open water conditions in the middle of the Arctic winter. Between March and early July 2013, a persistent ice cover-modulated air-sea fluxes. Melting sea ice at the start of the winter initiates a cold, up to 100-m-deep halocline separating the ice cover from the warm Atlantic Water. Semidiurnal tides dominate the energy over the upper part of the slope. The vertical tidal structure depends on stratification and varies seasonally, with the potential to contribute to vertical fluxes with shear-driven mixing. Further processes impacting the heat budget include lateral heat loss due to mesoscale eddies, and modest and negligible contributions of Ekman pumping and shelf break upwelling, respectively. The continental slope north of Svalbard is a key example regarding the role of ocean heat for the sea ice cover. Our study underlines the complexity of the ocean’s heat budget that is sensitive to the balance between oceanic heat advection, vertical fluxes, air-sea interaction, and the sea ice cover.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Peer revision
Peer-reviewed
Publication Status
Published
Eprint ID
52593
DOI 10.1029/2018JC013814

Cite as
Renner, A. H. H. , Sundfjord, A. , Janout, M. A. , Ingvaldsen, R. B. , Beszczynska‐Möller, A. , Pickart, R. S. and Pérez‐Hernández, M. D. (2018): Variability and Redistribution of Heat in the Atlantic Water Boundary Current North of Svalbard , Journal of Geophysical Research: Oceans, 123 (9), pp. 6373-6391 . doi: 10.1029/2018JC013814


Download
[img]
Preview
PDF
Renner_et_al-2018-Journal_of_Geophysical_Research_Oceans.pdf

Download (3MB) | Preview

Share


Citation

Research Platforms
N/A

Campaigns


Actions
Edit Item Edit Item