Surface Heat Flux Corrections for Global Ocean Forecasts
Zulema D Garraffo1, Patrick J Hogan2, Avichal Mehra3, Ilya Rivin4, Bhavani Balasubramaniyan4, Todd D Spindler4, Hae-Cheol Kim1 and Shastri Paturi1, (1)IMSG at NOAA/NWS/NCEP/EMC, College Park, MD, United States, (2)US Naval Research Laboratory, Oceanography Division, Stennis Space Center, MS, United States, (3)NOAA/NWS/NCEP/EMC, College Park, MD, United States, (4)IMSG, NCEP / Environmental Modeling Center, College Park, MD, United States
Abstract:
RTOFS (Real Time Ocean Forecast System) - Global is the first global eddy resolving ocean forecast system implemented operationally at NOAA/NWS/NCEP in close collaboration with US Navy. Recently upgraded version 1.1 (which was developed and validated at NRL) uses the Hybrid Coordinates Ocean Model (HYCOM) at 1/12 degree coupled with Los Alamos Community sea ICE model (CICE). The forecast system runs once a day and produces forecasts from the daily initialization fields produced at NAVOCEANO (NAVal OCEANographic Office) which use NCODA (Navy Coupled Ocean Data Assimilation), a 3DVAR data assimilation methodology (Cummings and Smedstad, 2013). After a two-day spin up with hourly NCEP’s Global Data Assimilation System (GDAS) atmospheric fluxes with the ocean model in forecast mode, the daily forecast cycle is forced with 3-hourly momentum, radiation and precipitation fluxes from NCEP’s Global Forecast System fields for the next eight days. Following flux-corrections efforts at NRL (Metzger et al. 2013, NRL report), heat flux corrections are computed for the RTOFS v1.1 configuration. To assess sensitivity to upgrades in GFS/GDAS and HYCOM, these radiative corrections are compared with forecasts produced with other versions of NCEP forcing. Impacts of flux corrections in SST errors will be discussed.
