Abstract
AbstractThe poleward flow of Atlantic Water in the Nordic Seas forms the upper limb of the meridional overturning circulation driving an important heat transport. The Norwegian Atlantic Front Current along the Mohn Ridge between the Greenland and Norwegian Seas is characterized for the first time, using repeated sections over 14 months from autonomous underwater gliders and two research cruises. The Norwegian Atlantic Front Current follows the 2,550‐m isobath with a width of 38 ± 2 km and absolute geostrophic velocities peaking at 0.56 ± 0.03 m s−1. The mean transport of Atlantic Water is 3.2 ± 0.2 Sv (equivalent to temperature transport of 71 ± 5 TW). Seasonal variability was observed with a magnitude of 0.8 Sv and maximum values in the fall. The deep currents at 1,000 m explained most of this seasonal variation and were anticorrelated with time‐integrated wind stress curl over the Lofoten Basin. Part of this flow might recirculate within the Lofoten Basin, while the rest continues toward the Arctic.
Highlights
Ocean circulation plays a key role in the climate system by redistributing heat from low to high latitudes (Ganachaud & Wunsch, 2000)
The Norwegian Atlantic Front Current along the Mohn Ridge between the Greenland and Norwegian Seas is characterized for the first time, using repeated sections over 14 months from autonomous underwater gliders and two research cruises
The ocean currents carrying warm Atlantic Water (AW) in the Nordic Seas are organized in two poleward branches (Orvik & Niiler, 2002) (Figure 1a): the barotropic Norwegian Atlantic Slope Current (NwASC) and the baroclinic Norwegian Atlantic Front Current (NwAFC)
Summary
Ocean circulation plays a key role in the climate system by redistributing heat from low to high latitudes (Ganachaud & Wunsch, 2000). South of the Vøring Plateau at the Svinøy section (63◦ N), continuous measurements since 1995 set the NwASC annual transport to 4.2–4.4 Sv (Orvik & Skagseth, 2003; Orvik et al, 2001) (Sv = 106 m3 s−1) This barotropic branch is relatively well constrained by observations. Similar baroclinic transport calculations using limited surveys gave 2.4 Sv over the Mohn Ridge (Gascard et al, 2004), 2.6 Sv (Walczowski et al, 2005) and 3 Sv (van Aken et al, 1995) over the Knipovich Ridge While these transports are roughly consistent, all exclude the barotropic contribution which was suggested to be important using theoretical arguments (Orvik, 2004), limited deep current profiling (Walczowski et al, 2005), and Geophysical Research Letters. The NwAFC at the Mohn Ridge is a key contributor to redistribution of the AW heat toward the Arctic and must be monitored
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
