MERCATOR OCEAN JOURNA: 
SEPTEMBER 2021 
methods and model parametrization choices. The four 
members and their daily 3D mean and standard deviation 
were exploited to derive envelopes of estimates for several 
global ocean monitoring indicators (o0cean heat Ccontent 
(OHC) and Ssteric Ssea lLevel, nino3.4 indices, Ssea lice 
eExtent, ocean volume and heat transports ...) published in 
the Ocean State Report. The signal-to-noise ratio highlights 
the most robust spatial structures on the OHCcean Heat 
Content trend maps (https://marine.copernicus.eu/ 
access-data/ocean-monitoring-indicators/global-trend- 
mMap-ocean-heat-content). Figure 4 illustrates, for instance, 
uncertainty of the sea ice extent in the Arctic Ocean 
computed from 1993 to 2018. The trend and interannuaı 
variability are similar between the four estimates based or 
avallable global reanalysies. Uncertainty decreased over 
time thanks to iImprovement of assimilated data set. 
Northern Hemisphere Sea Ice Extent 
13.0 
% 
= 
CZ 
7 125 
120 
11.5 
DD 
U 
A 
11.0 
10.5 
GLORYS2V4 5m 1 FOAM 
C-GLORS a MEAN 
=» ORAS5 
‚9 
„09% 
„0 
„09 
„1 
„0% 
„09° 
„SS 
„0 
„0 
„0 
„8 
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Ve 
ear SE 
„N 
40° 
„8 
2 
4 
4805 
„8 
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48 
‚igure k&: Sea ice extent ocean monitoring indicator in the Arctic Ocean computed with the four global reanalysis available in the multi 
3yvstem ensemble product (GREP)}. 
2. STATUS AT THE END OF COPERNICUS 1 
—“ 
During Copernicus 1 a lot of developments have been 
performed to improve and to optimise existing systems, to 
develop new products and new systems and to improve 
the consistency of existing systems in terms of resolution; 
time extension for reanalysis; or forecast length; available 
variables; model configuration; and parameterisations 
Current near real time forecasting systems provide 
physical, waves, sea ice and biogeochemistry products 
with the following main characteristics and evolution 
during Copernicus 1: 
- GLOBAL 1/12° physical forecasting system (GLO12v3); 
based on NEMO model assimilating SLA, T/S profiles, 
SST, SIC; forced by ECMWF operational analysis and 
forecast and providing physical and sea ice 10-day daily 
forecast; is available since November 2016 on 1/12° 
regular arid. In April 2019, a new Surface and Meraged 
Ocean Currents (SMOC) product was developed and, 
ın March 2020, 3D 6-hourly frequency products were 
added in the catalogue, 
GLOBAL 1/4° biogeochemical forecasting system 
(GLO4v2); based on PISCES model assimilating Ocean 
Colour satellite observations; forced by GLO12v3 and 
providing 14-day weekly forecast; is available on 1/4° 
-egular grid since July 2019, 
GLOBAL 1/10° wave forecast (WAVEv2); based on 
MFWAM model assimilating SWH and directional wave 
spectra from Sentinel-1; forced by ECMWF operationa. 
analysis and forecast and GLO12v3 surface current and 
providing daily 5-day forecast; is available on 1/12° 
regular grid since April 2018. In December 2020, the 
forecast length was extended to 10-day. 
The global reanalysis systems are consistent with the 
near real time systems, using the same models and data 
assimilation methods and providing the same varlables. 
The, main characteristics and evolution during Copernicus 
1 are the following: