Evolution of chemical, biological, and physical water properties in the northern California Current in 2005: Remote or local wind forcing?

The spring onset of persistent upwelling‐favorable winds was later than usual in the northern California Current system in 2005, resulting in delayed provision of inorganic nutrients to the upper waters of the coastal ocean. This study uses water column measurements to illustrate the evolution of temperature, salinity, nitrate and chlorophyll a prior to and after the onset of persistent local upwelling‐favorable winds, including recovery to “typical” conditions. Warm, nutrient‐ and chlorophyll‐depleted surface conditions similar to those in an El Niño were observed from Vancouver Island to central Oregon, and extended to depths greater than 500 m. Return to typical conditions was more rapid than suggested by time‐integrated local wind stress but consistent in timing with “remote” forcing of water properties in this region by upwelling‐favorable winds off northern California. Alongshore advection also likely contributed to the observed recovery, but was much less effective than upwelling.