Development and Code Infrastructure of The Coastal Modeling Framework Based on Unified Forecast System (UFS-Coastal)

As a part of the ongoing effort of NOAA to simplify its Modeling Production Suite and migrate to Unified Forecast System (UFS), a new application that aims to support forecast requirements of coastal applications is being developed at the Coastal Marine Modeling Branch (CMMB, NOAA/NOS/OCS). The new application, named as UFS Coastal (UFS-Coastal) mainly shares the same infrastructure with the UFS Weather Model and its components along with specialized coastal ocean model components such as ADCIRC, FVCOM, ROMS, SCHISM and the Parametric Hurricane Modeling System (PaHM). The new application is flexible enough to combine different components of the modeling system through the use of ESMF/NUOPC (Earth System Modeling Framework/National Unified Operational Prediction Capability) layer to meet specific application requirements. For instance, the UFS Weather Model provided CDEPS (Community Data Models for Earth Prediction Systems) data component capability can be combined along with the active ocean model component to isolate two-way interactions and complex feedbacks in the air-sea interface and to enable better understanding of storm surge and their effects. Moreover, the ESMF/NUOPC based CMEPS (Community Mediator for Earth Prediction Systems) mediator component can be also used to define complex interactions among different model components like mapping and merging of exchange fields to provide a flexible coupling infrastructure.

It also enables testing and use of state-of-art coupling technologies such as exchange grid approach to calculate atmosphere-ocean fluxes and coupling through the nested domains without any major development. Sharing the same infrastructure with UFS Weather Model is also critical to reduce redundancy and improve efficiency across different applications and facilitates the use of new features developed in one application with the others like UFS-Coastal. To this end, this study aims to introduce the details of the newly developed UFS-Coastal application along with its capabilities and components to the earth system modeling community that might have interest in using it for scientific or forecasting purposes.