The article of record as published may be found at http://dx.doi.org/10.1002/jgrc.20400The network comprising 61 high-frequency radar systems along the U.S. West Coast
(USWC) provides a unique, high resolution, and broad scale view of ocean surface
circulation. Subinertial alongshore surface currents show poleward propagating signals with
phase speeds of O(10) and O(100–300) km d 1 that are consistent with historical in situ
observations off the USWC and that can be possibly interpreted as coastally trapped waves
(CTWs). The propagating signals in the slow mode are partly observed in southern
California, which may result from scattering and reflection of higher-mode CTWs due to
curvature of shoreline and bathymetry near Point Conception, California. On the other hand,
considering the order of the phase speed in the slow mode, the poleward propagating signals
may be attributed to alongshore advection or pressure-driven flows. A statistical regression
of coastal winds at National Data Buoy Center buoys on the observed surface currents
partitions locally and remotely wind-forced components, isolates footprints of the
equatorward propagating storm events in winter off the USWC, and shows the poleward
propagating signals year round.National Research Foundation (NRF)Ministry of EducationHuman Resources Development of the Korea Institute of Energy Technology Evaluation and Planning (KETEP)Ministry of Trade, Industry and EnergyRepublic of Koreano. 2013R1A1A2057849no. 2011403020004
