SeaWiFS monitors ocean plant life by measuring the amount of chlorophyll in the ocean. Large phytoplankton blooms tend to coincide with natural phenomena that drive that nutrient-rich water to the surface. The process is called upwelling. Winds coming off principal land masses push surface layers of water away from the shore. Into the resulting wind-driven void deeper water underneath the surface layers rushes in toward the coast, bringing with it nutrients for life to bloom. This upwelling fuel the growth of marine phytoplankton which, along with larger seaweeds, nourishes the incredible diversity of creatures found along the northern and central California coast.