The California Current System: A multiscale overview and the development of a feature-oriented regional modeling system (FORMS)

• Main Authors: Gangopadhyaya, Avijit, Lermusiaux, Pierre F.J., Rosenfeld, Leslie, Robinson, Allan R., Calado, Leandro, Kim, Hyun Sook, Leslie, Wayne G., Haley, Patrick J. Jr.
• Other Authors: Naval Postgraduate School (U.S.)
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2021
• Subjects: Pacific; North Atlantic
• Online Access: https://hdl.handle.net/10945/68925

17 USC 105 interim-entered record; under review. Over the past decade, the feature-oriented regional modeling methodology has been developed and applied in several ocean domains, including the western North Atlantic and tropical North Atlantic. This methodology is model-independent and can be utilized with or without satellite and/or in situ observations. Here we develop new feature-oriented models for the eastern North Pacific from 36◦ to 48◦N – essentially, most of the regional eastern boundary current. This is the firsttime feature-modeling has been applied to a complex eastern boundary current system. As a prerequisite to feature modeling, prevalent features that comprise the multiscale and complex circulation in the California Current system (CCS) are first overviewed. This description is based on contemporary understanding ofthe features and their dominant space and time scales of variability. A synergistic configuration of circulation features interacting with one another on multiple and sometimes overlapping space and time scales as a meander-eddy-upwelling system is presented. The second step is to define the feature-oriented regional modeling system (FORMS). The major multiscale circulation features include the mean flow and southeastward meandering jet(s) of the California Current (CC), the poleward flowing California Undercurrent (CUC), and six upwelling regions along the coastline. Next, the typical synoptic width, location, vertical extent, and core characteristics of these features and their dominant scales of variability are identified from past observational, theoretical and modeling studies. The parameterized features are then melded with the climatology, in situ and remotely sensed data, as available. The methodology is exemplified here for initialization of primitiveequation models. Dynamical simulations are run as nowcasts and short-term (4–6 weeks) forecasts using these feature models (FM) as initial fields and the Princeton Ocean Model (POM) for dynamics. The set of simulations over a ...