Verification of Mercator Ocean global ocean forecasts

Mercator Ocean, based in Toulouse, France, provides operational oceanography services, and is entrusted by the European Commission to implement the Copernicus Marine Environment Monitoring Service CMEMS. As part of these services, Mercator Ocean develops and operates ocean analysis and forecasting systems based on the Ocean General Circulation Model NEMO, assimilating satellite and in situ observations of the Global Ocean Observing System. The global ocean 10-day forecasts are updated daily, and their horizontal resolution is 1/12° (~9km), which allows describing accurately the largest mesoscale features in the ocean. Biogeochemical Ocean forecasts are also produced, at a coarser resolution (~ 25km), providing information on large categories planktons and nutrients which are the first levels of the trophic chain in the ocean. The verification of these physical and biogeochemical forecasts is based on standards developed by the GODAE/Oceanpredict community, and by the CMEMS product quality working group. In this presentation, we will discuss the metrics which are used, and their representativeness depending on the variable and on the reference observations that are available.  In particular, recent results from the comparison of several forecast lengths with observed velocities will be shown.