Observations of the Surface Circulation over the Mid Atlantic Bight Continental Shelf

What is understood about the mean and seasonal flow off the Mid Atlantic Bight has been gathered with point measurements that span on average of a single year. The spatial structure and interannual variability of the flow can be resolved further. The mean and seasonal surface circulation of the Mid Atlantic Bight was measured using eight years of High Frequency radar data (2007-2014). The data was binned into seasonal and annual time frames and analyzed. The mean surface flow over the eight year study period is 3-6 cm/s down shelf and offshore to the south. There is an intensification seaward of the 50 m isobath to a speed 6-9 cm/s. When the water reaches Cape Hatteras to the south it is then advected towards the northeast by the Gulf Stream. The surface current asymptotes at 9 cm/s shoreward of the 100 m isobath, which matches the measurements of the Oleander Project. The data was compared on a seasonal cycle and the fall of 2009 displayed a surface current that was twice the magnitude of the eight-year record. This higher than normal surface current also coincided with an extreme event of sea-level rise along the northeast coast of North America in 2009-2010. The measurements show good agreement with the model of Lentz (2008) and help fill in the sparsity and unevenness of the acoustic current measurements.