Building a dynamic middleware framework to couple 2D ocean circulation models to the National Water Model
Abstract
The National Water Model (NWM) simulates the hydrologic cycle using physical and conceptual representations of processes over the entire continental United States. However, representing total water levels in complex coastal areas still proves to be a challenge for the NWM. Here, we use the D-Flow Flexible Mesh (D-Flow FM) as a "middleware" framework that allows for the transition of 2D oceanic circulation and wave models, such as the Advanced Circulation Ocean Model (ADCIRC) and WAVEWATCH III (WW3), to the NWM inland hydraulic grid using a coupling framework called NOAA Environmental Modeling System (NEMS).
We developed the NEMS infrastructure and modeling framework for D-Flow FM, NWM, ADCIRC, and WW3 model components to simulate coastal zone flooding events and total water levels for the purpose of the Consumer Option for an Alternative System to Allocate Losses (COASTAL) Act of 2012. NEMS is built using the Earth System Modeling Framework (ESMF) software, which allows model components to independently use grid interpolation methods, time management tools, and wrappers on a standard interface. The National Unified Operational Capability (NUOPC) Fortran code adapter (i.e. cap) enables models to effectively build dependencies to standardize a model's main program and exchange variable fields between model components. We created a NUOPC cap for the NWM and D-Flow FM models to interoperate with the already developed ADCIRC and WW3 NUOPC caps for the COASTAL Act. To fully couple NWM and D-Flow FM model components, revisions to internal source code routines and NEMS field exchanges were warranted to allow D-Flow FM to ingest ocean circulation model fields as well as NWM route link features. The NEMS workflow structure contained within the COASTAL Act modeling framework was evaluated for a handful of Named Storm (tropical cyclone) scenarios covering the contiguous United States, Hawaii, and Puerto Rico/US Virgin Islands. Considering the stability and skill of the D-Flow FM model coupled with 2D ocean circulation models and the NWM, we can now use this modeling framework between the NWM and D-Flow FM as an extension for NWM forecasting schemes over the coastal zones. With the NextGen Water Modeling Framework now in development, we can implement D-Flow FM as a model component for a given watershed within the hydrofabric of the NWM.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.H45I1498D