 |
| Titel |
Tides stir up deep Arctic heat |
| VerfasserIn |
Mattias Green, Tom Rippeth, Ben Lincoln, Yueng Lenn, Sheldon Bacon, Arild Sundfjord |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250104349
|
| Publikation (Nr.) |
 EGU/EGU2015-11582.pdf |
|
|
|
|
|
| Zusammenfassung |
| The Arctic is warming at twice the rate of the rest of the planet. One of the largest sources
of heat to the Arctic Ocean is the warm salty Atlantic water (AW) which enters
through the Fram Strait and circulates at intermediate depth round the Arctic basin.
The heat contained in the AW is sufficient to entirely melt the Arctic sea ice but
is insulated from the surface by a layer of colder fresher water. Across much of
the Arctic Ocean there is insufficient turbulence to drive vertical mixing, and so
heat fluxes are a result of double diffusion (DD) and are consequently weak (< 0.1
WÂm-2). Here we present a new pan-Arctic series of direct measurements of TKE
dissipation rate. The new measurements show enhanced turbulent mixing, and hence
heat fluxes, over much of the continental slope around the Arctic boundary. The
rate of TKE dissipation is found to increase with the bathymetric slope and vary
longitudinally with the largest values to the north of Svalbard resulting in enhanced
diapycnal heat fluxes over this region (20 WÂm-2). The observed 2-order of magnitude
longitudinal variation in TKE dissipation rate correlates with the rate of dissipation of
tidal energy, estimated from the local difference between the work done by the tide
generating force and the tidal energy flux divergence from the TPXO8 inverse tidal
solution. This correlation leads to the conclusion that the enhanced mixing observed
over the continental shelf break north of Svalbard is a result of tidal processes. |
|
|
|
|
|
|