Synchronicity of the Gulf Stream path downstream of Cape Hatteras and the region of maximum wind stress curl.

The Gulf Stream, a major ocean current in the North Atlantic ocean is a key component in the global redistribution of heat and is important for marine ecosystems. Based on 27 years (1993-2019) of wind reanalysis and satellite altimetry measurements, we present observational evidence that the path of this freely meandering jet after its separation from the continental slope at Cape Hatteras, aligns with the region of maximum cyclonic vorticity of the wind stress field known as the positive vorticity pool. This synchronicity between the wind stress curl maximum region and the Gulf Stream path is observed at multiple time-scales ranging from months to decades, spanning a distance of 1500 km between 70 and 55W.

Modes of North Atlantic Western boundary current variability at 36° N.

The surface-intensified, poleward-flowing Gulf Stream (GS) encounters the equatorward-flowing Deep Western Boundary Current (DWBC) at 36° N off Cape Hatteras. In this study, daily output from a data-assimilative, high-resolution (800 m), regional ocean reanalysis was examined to quantify variability in the velocity structure of the GS and DWBC during 2017-2018. The validity of this reanalysis was confirmed with independent observations of ocean velocity and density that demonstrate a high level of realism in the model's representation of the regional circulation.

Continuous Flow of Upper Labrador Sea Water around Cape Hatteras.

Six velocity sections straddling Cape Hatteras show a deep counterflow rounding the Cape wedged beneath the poleward flowing Gulf Stream and the continental slope. This counterflow is likely the upper part of the equatorward-flowing Deep Western Boundary Current (DWBC). Hydrographic data suggest that the equatorward flow sampled by the shipboard 38 kHz ADCP comprises the Upper Labrador Sea Water (ULSW) layer and top of the Classical Labrador Sea Water (CLSW) layer.

Direct interaction between the Gulf Stream and the shelfbreak south of New England.

Sea surface temperature imagery, satellite altimetry, and a surface drifter track reveal an unusual tilt in the Gulf Stream path that brought the Gulf Stream to 39.9°N near the Middle Atlantic Bight shelfbreak--200 km north of its mean position--in October 2011, while a large meander brought Gulf Stream water within 12 km of the shelfbreak in December 2011. Near-bottom temperature measurements from lobster traps on the outer continental shelf south of New England show distinct warming events (temperature increases exceeding 6°C) in November and December 2011.