Skillful multiyear predictions of ocean acidification in the California Current System

The California Current System (CCS) sustains valuable fisheries yet is highly vulnerable to ocean acidification due to upwelling of carbon-enriched waters. Using a novel suite of retrospective, initialized ensemble forecasts with an Earth system model (CESM-DPLE), the study predicts the evolution of surface pH anomalies in the CCS. The forecast system skillfully predicts observed surface pH variations one year in advance over a persistence baseline, with potential skill up to five years. Predictive skill arises mainly from initializing dissolved inorganic carbon (DIC) anomalies that are transported into the CCS. Results demonstrate the potential for Earth system models to provide skillful multiyear predictions of ocean acidification at large scales in the CCS and to supply boundary conditions for higher-resolution regional forecasting systems.

Riley X. Brady, Nicole S. Lovenduski, Stephen G. Yeager, Matthew C. Long, Keith Lindsay