Abstract
The flow of warm and saline water from the Atlantic
Ocean, across the Greenland–Scotland Ridge, into the
Nordic Seas – the Atlantic inflow – is split into three separate
branches. The most intense of these branches is the inflow
between Iceland and the Faroe Islands (Faroes), which
is focused into the Faroe Current, north of the Faroes. The
Atlantic inflow is an integral part of the North Atlantic thermohaline
circulation (THC), which is projected to weaken
during the 21st century and might conceivably reduce the
oceanic heat and salt transports towards the Arctic. Since the
mid-1990s, hydrographic properties and current velocities of
the Faroe Current have been monitored along a section extending
north from the Faroe shelf. From these in situ observations,
time series of volume, heat, and salt transport have
previously been reported, but the high variability of the transport
has made it difficult to establish whether there are trends.
Here, we present results from a new analysis of the Faroe
Current where the in situ observations have been combined
with satellite altimetry. For the period 1993 to 2013, we find
the average volume transport of Atlantic water in the Faroe
Current to be 3.80.5 Sv (1 SvD 106 m3 s1/ with a heat
transport relative to 0 C of 12415TW (1TWD 1012 W).
Consistent with other results for the Northeast Atlantic component
of the THC, we find no indication of weakening. The
transports of the Faroe Current, on the contrary, increased.
The overall increase over the 2 decades of observation was
98% for volume transport and 189% for heat transport
(95% confidence intervals). During the same period, the salt
transport relative to the salinity of the deep Faroe Bank Channel
overflow (34.93) more than doubled, potentially strengthening
the feedback on thermohaline intensity. The increased
heat and salt transports are partly caused by the increased
volume transport and partly by increased temperatures and
salinities of the Atlantic inflow, which have been claimed
mainly to be caused by the weakened subpolar gyre.
Ocean, across the Greenland–Scotland Ridge, into the
Nordic Seas – the Atlantic inflow – is split into three separate
branches. The most intense of these branches is the inflow
between Iceland and the Faroe Islands (Faroes), which
is focused into the Faroe Current, north of the Faroes. The
Atlantic inflow is an integral part of the North Atlantic thermohaline
circulation (THC), which is projected to weaken
during the 21st century and might conceivably reduce the
oceanic heat and salt transports towards the Arctic. Since the
mid-1990s, hydrographic properties and current velocities of
the Faroe Current have been monitored along a section extending
north from the Faroe shelf. From these in situ observations,
time series of volume, heat, and salt transport have
previously been reported, but the high variability of the transport
has made it difficult to establish whether there are trends.
Here, we present results from a new analysis of the Faroe
Current where the in situ observations have been combined
with satellite altimetry. For the period 1993 to 2013, we find
the average volume transport of Atlantic water in the Faroe
Current to be 3.80.5 Sv (1 SvD 106 m3 s1/ with a heat
transport relative to 0 C of 12415TW (1TWD 1012 W).
Consistent with other results for the Northeast Atlantic component
of the THC, we find no indication of weakening. The
transports of the Faroe Current, on the contrary, increased.
The overall increase over the 2 decades of observation was
98% for volume transport and 189% for heat transport
(95% confidence intervals). During the same period, the salt
transport relative to the salinity of the deep Faroe Bank Channel
overflow (34.93) more than doubled, potentially strengthening
the feedback on thermohaline intensity. The increased
heat and salt transports are partly caused by the increased
volume transport and partly by increased temperatures and
salinities of the Atlantic inflow, which have been claimed
mainly to be caused by the weakened subpolar gyre.
| Original language | English |
|---|---|
| Pages (from-to) | 743-757 |
| Journal | Ocean Science |
| Volume | 11 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 2015 |
