Bio@Noon – Dr. Sophie Clayton – California Current System

Dr. Sophie Clayton, November 18, 2020

Eddies and filaments mediate biogeochemical and ecological succession of coastal upwelled waters in the California Current System.

The California Current System is characterized by an equatorward flowing eastern boundary current, as well as seasonal wind-driven coastal upwelling which supplies nutrient-rich waters to the surface and drives high coastal productivity. The transport of these upwelled waters offshore is mediated by mesoscale eddies and submesoscale filaments. In this study, we sampled a series of submesoscale and mesoscale features to characterize the chemical and biological evolution of upwelled waters as they are transported from the coastal zone offshore. The features sampled included a filament of freshly upwelled waters, a “young” cyclonic eddy (~1 month old), an “old” cyclonic eddy (~10 months old) and an anticyclone. We combine observations of dissolved inorganic nutrients, trace metals, phytoplankton community composition and photophysiology. We find that upwelled nutrients (including trace metals) are differentially drawn down as they are transported away from the coast. This is also reflected in changes in the composition of the phytoplankton community, as well as pronounced shifts in the photophysiological status of the phytoplankton community.