Biogeochemical Properties of Eddies in the California Current System

The California Current System is known for its high coastal biological production, contrasting with oligotrophic offshore waters. The resulting cross-shore gradient of biological and physical properties is perturbed by strong mesoscale eddy activity. Eddies that are formed at the coast move offshore, entraining and redistributing nearshore nutrients and planktonic organisms. However, the ecosystems within eddies often differ, potentially due to the age of the eddy, the time and the location of its formation, or its nature – cyclonic eddies (CE) vs. anticyclonic eddies (ACE). To characterize and quantify the ability of mesoscale eddies to affect local and regional planktonic ecosystems in the CCS we coupled the Regional Ocean Modeling system with a planktonic ecosystem model. Over a 10-year-long climatological model solution, we identified CE and ACE. Biogeochemical properties are quantified along their trajectories. This study highlights the differential role of CE and ACE: CE efficiently transport coastal planktonic organisms and maintain local production based on recycling and local vertical nitrate inputs, whereas ACE have enhanced exchange with surrounding waters, diluting the ecosystems within them.