RE 
BERTINO, L.'. ALI, A.?. CARRASCO, A.?. LIEN, V.S.". MELSOM, A.} 
Nansen Environmental and Remote Sensing Center, Bergen, Norway - *MET Norway, Bergen, Norway - MET Norway, Oslo, Norway 
“Institute of Marine Research, Bergen, Norway 
OVERVIER” 
During the 2015-2021 period, the Copernicus Marine 
Service has diversified its Arctic portfolio of modeling 
products. The addition of waves, tides and ocean carbon 
variables satisfies more adequately user needs in the 
industry, academia and public sectors. Many validation 
metrics have also been introduced, providing more intuitive 
forecast quality measures. The resolution of several 
products has increased, such as ice forecasts horizontal 
resolution thanks to a standalone sea ice model based on 
a new rheology. At the end of the Copernicus 1 period the 
products are using the model and assimilation systems 
TOPAZ, neXtSIM and WAM. 
1. MAIN ACHIEVEMENTS 2015-2021 
When Copernicus Services started in 2015, the Arctic 
MFC provided four forecasts and reanalyses products of 
physical and biogeochemical variables. These products 
were based on the TOPAZ system, which leverages 
Ensemble Kalman Filter (EnKF) data assimilation 
applied to satellite ocean observations (SLA, SST), sea 
ice observations (concentration and drift) and in situ T/S 
profiles (from Argo and Ice-Tethered Profilers) in a coupled 
oahysical-biogeochemical model. Using an advanced EnKF 
assimilation algorithm in operational settings is still today 
a unique achievement. 
The HYbrid vertical Coordinate Ocean Model (HYCOM) was 
the ocean model, coupled to the CICE sea ice model using 
an Elasto-Viscous-Plastic rheology and coupled online to 
the NORWECOM biogeochemical model. All products had a 
resolution of 12.5 km or coarser - interpolated to a polar 
stereographic projection - and 28 hybrid z-isopycnic layers, 
interpolated to 12 “Levitus” vertical levels. There was no 
nesting between Global and Arctic systems 
1.1 Waves 
A pan-Arctic operational wave forecast product (see domain 
on Figure 1) has been first setup using the WAM model 
zode from the MyWave FP7 project. The code has been 
modified by MET Norway to allow wave propagation under 
sea ice (Sutherland et al., 2019). Sea ice concentration, ice 
thickness and surface currents are all extracted from the 
Arctic MFC physical forecast. In 2019, the model horizonta 
resolution increased from 8 km to 3 km and two forecasts 
were run daily with an horizon of 5 and 10 days respectively. 
A wave hindcast was later added to the CMEMS catalogue 
at 3 km resolution with an updated version of WAM. It 
included new physics, a mean wavenumber and mean 
“frequency reformulation as well as a new method to 
detect freak waves. The code has been enhanced as wel 
by correcting wave growth in very high winds and by 
allowing wave propagation under sea ice. A sub-grid scale 
aarametrization of “obstructions” is used. On the surface, 
NAMis forced by hourly winds merging the ERA5 reanalysis 
and a local refinement (shown as the rectangle in Figure 1} 
by a 2.5 km non-hydrostatic convection-permitting model 
"he wave products are exploited for navigation purposes. 
support to offshore operations and downscaling to coasta 
wave models, among other uses. The 3 km resolution 
products provides high enough quality to fill the mandate 
of the Norwegian preparedness services (search and 
rescue, oil spill response) and superseded pre-existing 
national systems