Central California's warm waves a clue to changing coastal currents


  • Colin Schultz


A quarter of the way up the crest of the California coast, a giant L-shaped headland reaches out to a peak at Point Conception. To the north of the headland, winds blowing off the Pacific Ocean induce strong coastal upwelling, bringing cold ocean water to the surface. To the east of Point Conception, warm water traveling up the California coast gets trapped in the Santa Barbara Channel, its path blocked by upwelling to the west and Santa Cruz, Santa Rosa, and San Miguel islands to the south. Previous research showed that when a low-pressure system passes through the region, the upwelling-inducing winds can die down, freeing the warm water trapped in the Santa Barbara Channel to continue its poleward journey. Using satellite, high-frequency radar, and instrumented moorings to observe water temperature and current velocity, Washburn et al. determined the intricacies of these poleward propagating warm-water flows.