OS048-04
Impacts of Wave-Coupling in the Unified Forecast System Seasonal to Subseasonal Model

Wednesday, 16 December 2020: 07:12
Virtual
Jessica Meixner1, Brandon G Reichl2, Shrinivas Moorthi1, Jiande Wang3, Lydia B Stefanova3, Denise Worthen4, Bin Li3, Jun Wang1, Alistair Adcroft5, Robert Hallberg6, Stephen Griffies7 and Avichal Mehra8, (1)NOAA/NWS/NCEP/EMC, College Park, MD, United States, (2)NOAA Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States, (3)IMSG at NOAA/NWS/NCEP/EMC, College Park, MD, United States, (4)IMSG/National Centers For Environmental Prediction-Environmental Modeling Center, College Park, MD, United States, (5)Princeton University, Princeton, NJ, United States, (6)NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States, (7)Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States, (8)National Centers For Environmental Prediction-Environmental Modeling Center, College Park, MD, United States
Recorded Presentation
Abstract:
In this talk we examine the wave-coupling impacts in the Unified Forecast System (UFS) Subseasonal to Seasonal model which is being developed for operational implementation in the Global Ensemble Forecast System (GEFS) v13 in FY2024. In this atmosphere-ocean-ice-wave coupled model the wave model receives 10m wind speed, currents and ice fractions from the atmosphere, ocean and ice models and in turn sends a sea-state dependent surface roughness length to the atmosphere and Stokes drift to the ocean for sea-state dependent Langmuir mixing. The atmospheric model is comprised of the Finite Volume Cubed Sphere (FV3) dynamical core and the Common Community Physics Package (CCPP) for the physics driver, with GFS physics and GFDL microphysics. The other model components are the Modular Ocean Model (MOM6), the Los Alamos Sea Ice Model (CICE5) and the WAVEWATCH III (WW3) wave model.

A series of prototype models are being created for model development and then benchmark studies of 35 day free forecasts initialized on the first and fifteenth of every month for seven years (April 2011- March 2018) are made. The impacts of including a wave model is determined by comparing the latest prototype with wave-coupling to a prior prototype in which the roughness length is calculated in the atmospheric model and the ocean model employs a parameterized Langmuir mixing, providing a realistic assessment of the impacts of including an active wave model in a global coupled system for seasonal-to-subseasonal time range.

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