I'll just toss this little essay out, it would benefit greatly from further development (or maybe abandonment):
Excessive heat accumulating in equator waters redistributes itself northward via the Gulf Stream (AMOC); however water volume entering the Arctic must be balanced by water volume leaving. That much was known in the nineteenth century.
Petermann's 1874 map envisioned the Gulf Stream reaching the central Arctic and creating a pocket of open water surrounded by land-based ice, with water volume balance restored by cold water exiting in the Labrador Current. The first half of this hypothesis wasn't abandoned until Nansen and Johansen set off for the pole from the frozen-in Fram in March 1895.
Modern oceanographic considerations (barotropic flow) instead force this branch of the Gulf Stream to follow shelf break bathymetry after rounding Svalbard. Although some Atlantic Water later returns centrally along the Lomonosov Ridge (still following bathymetry, now translocated continental shelf) the remnant core is by now too cool, deep and double-diffused to realize Petermann's hypothesis.
Open water is found north of Svalbard all year now as Gulf Stream (WSC) heat manages to come up somewhat from depth due in part to turbulent eddies over the Yermak Plateau. Return flow occurs primarily via an adjacent EGC countercurrent along east Greenland, with lesser and variable amounts returning through the Fram, CAA channels and the Bering Strait, but with volume numbers always quick to add up.
What then makes the Gulf Stream (WSC) turn right at Svalbard? It is being pushed from behind to move on but can't continue heading north (oceanographic theory) nor go left because it would be rebuffed by massive southward return flows of the EGC.
But if the EGC and the ice-melt freshwater it brings south have been tipped by ever-warming West Spitsbergen Current water into overall system instability, could flows, eddies or upwelling chimneys conceivably turn west advecting part of their flow, rounding north Greenland as we are perhaps seeing this week, with turbulent confusion in surface waters (and to some depth) at both the EGC crossing and the Lincoln Sea, with the Nares picking up the slack in return flow south? Indeed, several earlier current forks have occurred in the AMOC en route.
http://oceancurrents.rsmas.miami.edu/atlantic/spitsbergen.htmlhttps://www.npr.org/2018/04/13/602240020/atlantic-ocean-current-slows-down-to-1-000-year-low-studies-showThis, if it continues for a few weeks along the CAA as it appears to be doing, would lead to the anti-matter version of Petermann's idea, central ice surrounded on all sides by open water. Conceivably this might have happened to a limited extent in previous seasons (volume flow does slow in August per wipneus) but has not been noticeable because masked by more robust ice in earlier years and less diversion of WGC waters.
The gif below compares 2018 to prior Augusts for the years 2012-17, showing that the event this season has no counterpart in the earlier years available.
Here are three gateway papers (71+ cites) to the many many studies of this region, including Goszczko's 2018 review of regional Ekman transport, eddies and water chimneys:
The West Spitsbergen Current volume and heat transport from synoptic observations in summer
W Walczowski et al 28 June 2004 free full text
https://brage.bibsys.no/xmlui/bitstream/handle/11250/2366362/021202.pdf?sequence=1
Mesoscale eddies in the Fram Strait marginal ice zone during the 1983 and 1984 Marginal Ice Zone Experiments
J. A. Johannessen et al 30 June 1987
https://doi.org/10.1029/JC092iC07p06754 Cited by: 120
During the summer Marginal Ice Zone Experiment in Fram Strait in 1983 and 1984, fourteen mesoscale eddies, in both deep and shallow water, were studied between 78° and 81°N. Sampling combined satellite and aircraft remote sensing observations, conductivityâtemperatureâdepth observations, drift of surface and subsurface floats and current meter measurements. Typical scales of these eddies were 20â40 km. Rotation was mainly cyclonic with a maximum speed, in several cases subsurface of up to 40 cm sâ1. Observations further suggest that the eddy lifetime was at least 20 to 30 days. Five generation sources are suggested for these eddies. Several of the eddies were topographically trapped, while others, primarily formed by combined baroclinic and barotropic instability, moved as much as 10â15 km dâ1 with the mean current. The vorticity balance in the nontrapped eddies is dominated by the stretching of isopycnals accompanied by a change in the radial shear. In the most completely observed eddy south of 79°N the available potential energy exceeded the kinetic energy by a factor of 2. Quantitative estimates suggest that the abundance of these eddies enhances the ice edge melt up to 1â2 km dâ1.
A Comparative Study of Moored/Point and Acoustic Tomography/Integral Observations of Sound Speed in Fram Strait Using Objective Mapping Techniques
BD Dushaw and H Sagen 17 December 2015
https://doi.org/10.1175/JTECH-D-15-0251.1
Fram Strait, the passage between Spitsbergen and Greenland, is a significant âchoke pointâ for the general circulation of the worldâs oceans (Fieg et al. 2010; Schauer et al. 2008). This strait is the only deep connection between the Arctic and the worldâs oceans. Through this strait, warm, salty North Atlantic water flows northward in the West Spitzbergen Current, while cold, fresher water, together with considerable quantities of ice (Smedsrud et al. 2011), flows southward in the East Greenland Current. The transports of heat and salt between the Atlantic basin and the Arctic Basin by the deep and shallow current systems in Fram Strait are important aspects of ocean circulation, with profound impacts on the oceanâs climate.
The details of these current systems are, however, difficult to observe. Not only are the natural scales of variability small at these high latitudes but the powerful current systems have turbulent and recirculating features. These features influence and obscure transports of mass or heat. Eddy variability may be an important contributor to these transports.
The Fram Strait moored array (Fig. 1) has been deployed across the strait since 1997 to measure the properties of these current systems (Fieg et al. 2010; Schauer et al. 2008). Temperature, salinity, and current data from this array have been noted for their great variability (von Appen et al. 2015). Even with 16 moorings deployed along a 325-km line across the strait, however, the separation of the moorings (20â28 km) is a few times larger than the natural scales of variability, 4â10 km (Fieg et al. 2010; Nurser and Bacon 2014).
The moored array has therefore undersampled the ocean variability; the Fram Strait moored array forms an incoherent observing array. This situation has made it challenging to employ the moored array data directly to estimate heat flow (Schauer et al. 2008; Schauer and Beszczynska-Möller 2009), or as constraints on numerical ocean models through data assimilation. The high noise of the observations overwhelms the signals of interest to the ocean modelers and introduces the effects of aliasing. Other observing approaches, such as glider or conductivityâtemperatureâdepth (CTD) sections, have obvious, different sets of complications or deficiencies. It is clear that no one type of measurement offers a comprehensive solution to the observation problem in Fram Strait.