A data-assimilative model reanalysis of the U.S. Mid Atlantic Bight and Gulf of Maine: Configuration and comparison to observations and global ocean models

•4D-Var data assimilation produces skillful 15-year coastal circulation analysis.•Climatological data assimilation corrects open boundary data biases.•Downscaling with data assimilation improves on global models in the coastal ocean.•Coastal satellite altimetry improves sea level variability across all time scales.•Bottom temperatures that impact fisheries are modeled well.