NOAA Environmental Modeling System - EMC
NOAA Environmental Modeling System
The NOAA Environmental Modeling System (NEMS) is a unified community modeling system that supports multiple modeling applications. This diagram shows the main components in NEMS, including physical components such as atmosphere and ice models, mediators (couplers), and the sub-components of the atmosphere. The NEMS architecture is based on the Earth System Modeling Framework (ESMF).
NEMS is a shared, portable, high performance software superstructure and infrastructure for use in operational prediction models at the National Centers for Environmental Prediction (NCEP). It is also part of the National Unified Operational Predication Capability (NUOPC) with Navy and the Air Force, and will eventually provide support to the community through the Developmental Test Center (DTC). Currently, the Global Forecast System (GFS, both the earlier spectral model and current FV3GFS) , the Global Ensemble Forecast System (GEFS), the B-grid version of the Nonhydrostatic Multiscale Model (NMM-B), and the Flow-following finite-volume Icosahedral Model (FIM) are placed together within NEMS.
NOTE : As of 2017, EMC ceased development of the Global Spectral Model (GSM) and the NMM-B model, which is used in several NCEP mesoscale modeling systems (NAM, SREF, HIRESW). NOAA has committed to a multi-year plan to use the Next Generation Global Prediction System (NGGPS) as the foundation upon which to build a Unified Forecast System (UFS) for the NCEP Production Suite. The envisioned end state is a simplified production suite under this unified framework using a single dynamic core (the Finite Volume Cubed-Sphere (FV3) for all temporal and spatial model scales which is both fully coupled and ensemble-based, and built within the NEMS framework. The replacement of GSM-based GFS with the FV3 version of the FV3GFS was accomplished in June 2019.
Past Operational Implementations of NEMS at NCEP
- NMM-B with nests for operational NAM
- Global Spectral Model in Global Forecast System
- Hurricanes in a Multi-scale Ocean coupled Non-hydrostatic model (HMON)
- NEMS GFS Aerosol Component (NGAC)
- NMM-B Members of the Short-Range Ensemble Forecast System (SREF)
- NMM-B members of High-Resolution Ensemble Forecast System (HREF) / HiresW
- FV3 version of Global Forecast System with NEMS framework (June 2019)
- FV3 version of the Global Ensemble Forecast System (September 2020)
- Limited-area FV3 version in the High-Resolution Ensemble Forecast System (HREF, May 2021)