Beaufort Gyre

The Beaufort Gyre is a wind-driven ocean current located in the Arctic Ocean polar region. The gyre contains both ice and water. It accumulates fresh water by the process of melting the ice floating on the surface of the water.

Conditions in the Arctic have favored sea ice loss in recent years during the Northern Hemisphere summers. At the end of the 20th century, analyses of increasing Pacific Surface Water temperatures led to the discovery of a connection between these rising temperatures and the onset of severe loss of Arctic sea ice in the Beaufort Sea. A reason for the existence of this link was proposed: “...delayed winter ice formation allows for more efficient coupling between the ocean and wind forcing.” These dynamical mechanisms are observed in the spin-up and circulation of the Beaufort Gyre.

Housed in the western part of the Arctic Ocean is the Beaufort Gyre, whose growing reservoir of freshwater is shrouded in mystery. In recent years, this increasing freshwater content (FWC) has been the focal point of many studies, particularly those concerning coupled ocean-atmosphere dynamics. The majority of the Arctic’s freshwater content resides in the Beaufort Gyre. Although biased toward the Northern Hemisphere summer months, observations from submarines, ships, and stations on drifting ice suggest that the gyre has been expanding over the past two decades. Researchers have employed coupled sea-ice-ocean general circulation models in order to thoroughly analyze these observations. Model results show that Ekman transport plays an integral role in the variability of freshwater in the gyre, and thus in the Arctic Ocean. The prevailing rotational direction of the Beaufort Gyre is clockwise, following the prevailing wind circulation of the Polar High. Coriolis veers moving objects to the right in the northern hemisphere and 'to the right" is inwards in a clockwise rotating system. This is why anything floating, including fresher water tends to move toward the centre of the system. Indeed, there is a slight bulge in the centre of the Beaufort gyre when it is rotating in its predominant clockwise direction. If, as is speculated, as the Arctic Ocean becomes a heat collector resulting in a low pressure, counter clockwise rotating system, the Beaufort Gyre can be expected to follow suit and send the fresher water outward to be captured by the transpolar current. This could well bring up the saltier, slightly warmer Atlantic water which lies under the floating, fresher Arctic water.

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