February 17th, 2026
Key Findings
- A 10-km resolution Northeast Pacific Ocean modeling system (NEP10k) was developed to provide historical context for marine resource assessments.
- The model is based on the Modular Ocean Model (MOM6) and is coupled with the Carbon, Ocean Biogeochemistry and Lower Trophics (COBALT) model, representing ocean circulation, sea ice, and lower-trophic biogeochemistry.
- A 27-year hindcast simulation (1993–2019) shows that the model reproduces observed patterns in temperature, salinity, nutrients, oxygen, carbonate chemistry, and chlorophyll across the region.
- The model simulates the Bering Sea summer cold pool and the timing and strength of seasonal upwelling along the U.S. West Coast.
- Performance is reduced in regions with narrow shelves and complex seafloor topography, such as the southern California Bight; finer-resolution (~5 km) configurations are under development to address these limitations.
Elizabeth J. Drenkard, Charles A. Stock, Andrew C. Ross, Yi-Cheng Teng, Theresa Cordero, Wei Cheng, Alistair Adcroft, Enrique Curchitser, Raphael Dussin, Robert Hallberg, Claudine Hauri, Katherine Hedstrom, Albert Hermann, Michael G. Jacox, Kelly A. Kearney, Rémi Pagès, Darren J. Pilcher, Mercedes Pozo Buil, Vivek Seelanki, and Niki Zadeh. Geoscientific Model Development. DOI: 10.5194/gmd-18-5245-2025
Ocean conditions along the U.S. West Coast influence fisheries, marine ecosystems, and coastal economies. These conditions vary across the Northeast Pacific, from the eastern Bering Sea and Gulf of Alaska to the California Current System, which presents challenges for regional ocean modeling.
In this study, the authors describe the development of the NEP10k, designed specifically for this region. The model is based on the MOM6–COBALT framework and spans the eastern Bering Sea, Gulf of Alaska, California Current System, and adjacent offshore waters. It is driven by historical atmospheric and ocean data and represents ocean circulation, sea ice, and lower-trophic biogeochemistry. The modeling system is part of NOAA’s Changing Ecosystem and Fisheries Initiative.
Model performance was evaluated using a 27-year hindcast simulation (1993–2019), with comparisons to satellite observations, ocean measurements, and reanalysis datasets. The model reproduces key seasonal and regional patterns in temperature, salinity, nutrients, oxygen, carbonate chemistry, and chlorophyll. In the eastern Bering Sea, it simulates the summertime cold pool and tracks observed changes in its extent (see Figure). Along the U.S. West Coast, the model captures the timing and strength of seasonal upwelling that brings colder, nutrient-rich water to shelf ecosystems. The model also reproduces observation-based estimates of long-term changes in dissolved oxygen. The evaluation identifies limitations. While the 10-km grid resolves open-ocean and broad shelf processes, performance is reduced in regions with narrow shelves and complex seafloor topography, including the southern California Bight. The model underestimates some year-to-year variability in satellite-derived chlorophyll and shows regional biases in stratification and phytoplankton variability. Higher-resolution (~5 km) configurations and additional process-based analyses are under development to examine these issues.
The NEP10k modeling system provides a regional framework for analyzing historical ocean conditions and supporting applications that require consistent physical and biological information across the Northeast Pacific. This work supports NOAA’s efforts to advance ocean science and improve the accuracy of ocean and ecosystem forecasts.
Modeled Ocean Conditions and Ecosystem Features in the Northeast Pacific
