Subseasonal-to-Seasonal Predictions with the Navy Global Coupled Model (Invited Presentation)

The Navy Earth System Predictability Capability model (Navy-ESPC) is being developed at the Naval Research Laboratory to provide global environmental information to meet Navy and Department of Defense (DoD) operations and planning needs from the upper atmosphere to under the sea. This modeling system currently consists of coupling the NAVy Global Environmental Model (NAVGEM) atmosphere model to the Global Ocean Forecasting System version 3.1 (GOFS 3.1), which consist of HYbrid Coordinate Ocean Model (HYCOM) and the Community Ice CodE (CICE). This system is being developed to meet Navy needs for high-resolution global environmental forecasts on timescales from days to months. The design and implementation of the coupled architecture uses the Earth System Modeling Framework (ESMF) with the National Unified Operational Prediction Capability (NUOPC) standard in order to maximize flexibility in adopting future models. This presentation will describe the Navy-ESPC model, the loosely coupled data assimilation, ensemble technique, and compare results against stand-alone atmosphere and ocean/ice models and other operational models. In particular, we will focus on Subseasonal to Seasonal (S2S) predictions of in the atmosphere. We will diagnostics of the MJO, NAO, AAO, AO, PNA, and others. The Navy-ESPC prediction of these indices is comparable to other operational centers for individual forecasts with the MJO predictability out to about 20 days and other indices to about 10. We will also discuss the limitations of ensemble design and future work to address these limitations.