Patterns of upwelling and relaxation around Monterey Bay based on long-term observations of surface currents from high frequency radar

A five-year record of surface current observations from HF radar in the region around Monterey Bay are used to describe the dominant circulation patterns under upwelling- and downwelling-favorable wind forcing. Conditional averages based on local wind observations reveal more structure and intensity in the circulation patterns than do traditional temporal averages. The predominant upwelling circulation pattern in the region is found to reach full strength after about three days of persistent upwelling-favorable wind forcing. In the opposite phase under downwelling-favorable winds, the circulation patterns differ between summer and winter with evidence for strong connectivity between the offshore waters and the coastline around Monterey Bay in summer that is not present in winter.