On the intermediate depth waters of the Arctic Ocean
Abstract
The intermediate depth waters of the Arctic Ocean are supplied from the North Atlantic through Fram Strait and over the Barents Sea. Water flowing into the Arctic Ocean by these two paths results in two branches of apparent equal strength (≈2 Sv): the Fram Strait branch with relatively warm water flowing in by way of the West Spitsbergen Current, and the Barents Sea branch with water that has been cooled and made less saline in the Barents Sea. The two branches meet north of the Kara Sea, creating interleaving and inversions that diminish along their flow paths. The intermediate depth waters from these two sources may be further transformed by sinking shelf plumes, water made dense by freezing and ice growth on the shallow shelves. The descending density flows cool the Atlantic Layer and redistribute heat downwards. A calculation shows how the introduction of the dense shelf water penetrating the Atlantic Layer can explain the characteristics observed in the Canadian Basin water column. Clues to the circulation of the intermediate depth waters are provided by changes in the shapes of the Θ-S curves at different locations and by chlorofluorocarbon and silicate distributions. In the Eurasian Basin, the residence times of the intermediate depth waters given by chlorofluorocarbon concentrations are of the order of a decade, with the deeper layers being the oldest. In the Canadian Basin, the residence times are twice as long for similar depths. Several loops are identified in the Eurasian Basin, and similar flow pattern in the Canadian Basin is suggested based on properties of outflowing Canadian Basin water near the Morris Jesup Plateau.
- Publication:
-
Geophysical Monograph Series
- Pub Date:
- 1994
- DOI:
- 10.1029/GM085p0033
- Bibcode:
- 1994GMS....85...33R