Doug Vandemark (University of New Hampshire, United States); Julia Levin (Rutgers University, United States); John Wilkin (Rutgers University, United States)

The study investigates the accuracy of gridded altimeter-derived upper ocean current datasets along the NW Atlantic shelf oceans using long-term in situ surface and near-surface current measurements. The assessment focuses upon two operational multi-mission altimeter-based ocean surface current products, GlobCurrent and OSCAR. A central focus is on the applicability of such open ocean products for some aspects of regional coastal process studies. The in situ data utilized come from platforms within the US Integrated Ocean Observing System (US-IOOS), including the Gulf of Maine (GoM) moored network of buoy ADCP upper ocean current time series as well as HF radar data from Northeast Regional Association of Coastal Ocean Observing Systems (NERACOOS) and a Mid-Atlantic Bight (MAB) HF Radar (CODAR) network from the Mid-Atlantic Regional Coastal Ocean Observing System (MARCOOS). The latter provides daily spatial surface current coverage across the shelf from Cape Cod, MA to Cape Hatteras, NC. For the application aspects, several questions central to regional shelf dynamics at monthly to seasonal time scales are being assessed. These concern the relative rate of remote water mass inflows to the GoM and modulation of upstream shelf flows that appear to control seasonal and inter-annual hydrographic variability in the GoM and perhaps down to the Mid-Atlantic Bight. We intend to comprehensively document the quality of gridded altimeter-based ocean surface current products in comparison to ground truth and process study results obtained using coastally-processed along track altimeter data used in recent regional investigations.