MERCATOR OCEAN JOURNA: 
SEPTEMBER 2021 
Production Centres (Monitoring and Forecasting Centres 
[MFCs] and Thematic Assembly Centres for ocean 
observations [TACs]) achieve operational production of 
reanalyses (RAN) and reprocessed observational products 
(REP L3/L4 and delayed-time quality controlled in situ) 
using delayed time quality-controlled input observations 
and boundary conditions (e.g., reanalysed atmospheric 
forcing). Each centre possesses the expertise, and can 
make specific scientific choices, in order to provide state- 
of-the-art RAN or REP for each region (global and regiona! 
seas) and for all variables. 
As illustrated in Figure 1, the number of MYPs proposed to 
users has increased during the period 2015-2021, and 
many new products describing a larger number of 
Essential Ocean Variables are now available on the Marine 
Service catalogue, such as surface pH and CO, 
reconstructions, ocean currents deduced from altimetry, or 
the first wave model reanalyses. The Marine Service 
ensures the collection of “best quality” input data and 
maximal use of multiple observation systems. In the longer 
term, the Service aims at a fully consistent approach 
across global and regional reanalyses, organizing their 
inter-operability, their iInter-dependencies, and Joint 
operations closer to real time (a few months only) with a 
systematic yearly update. Therefore, specific cross-cutting 
coordination actions were led (see also). 
This article describes the Marine Service achievements 
during the Copernicus 1 period 2015-2021, including 
improvements for consistency (section 1), continuity (sectior 
2) and quality assurance (section 3) of Marine Service MYPs 
1. TOWARD MORE CONSISTENT 
MULTI-YEAR PRODUCTS 
As illustrated in Figure 2, the main upstream dependency for 
the Marine Service MYPs is the regular uptake of observations 
of past, state-of-the-art reprocessed satellite L2 products as 
well as collections of in situ databases. All RAN products, and 
many REP, need reanalysed atmospheric fields (ERAinterim, 
chen ERA5), are progressively making use of varying river 
inputs, and atmospheric deposition. During the period 2015- 
2021, high level coordination was set up with observation 
agencies (ESA, EUMETSAT, NASA, NOAA, etc.), with EMODNET, 
3s well as with other Copernicus services (Climate Change, 
Land, Emergency, Atmosphere) for the provision of reprocessed 
upstream data. This requires a dedicated effort of integratec 
»perations to ensure a fully consistent, long term approach, 
across the different service elements, organize their 
interoperability, their inter-dependencies, and Joint operations 
"he first steps toward this integration were: 
to promote the use of Marine Service catalogue 
products by the Marine Service producers as input, 
-to identify how and when the TACs and MFCs multi- 
year production schedules could be phased. 
Regarding the first objective, new products were designed 
and implemented in order to be used as reanalysis inputs: 
the REP of OSTIA SST being fully consistent with the real 
:ime SST product, and the easyCORA dataset, designed by 
‚NS TAC using the MFCs inputs 
1950 
: 1980 m 1990 
7900 2010 — 
307 
Type of observations 
& increasing density of the 
Dbservations network 
N Pl ad 
PA 
floats 
Multi-year ocean estimates 
with realistic long term trends 
Categories and time coverage of 
Copernicus Marine products 
& INnCredsiNnd GCCUFOCY at Small scales 
Multi-year ocean estimates 
with realistic mesoscale features and interannual 
variability 
I 7 7 Multi year ocean estimates 
with optimal use of the 
current obs network 
ll 
DA 
-igure 2: Schematic of the time coverage over past decades depending on the type of observations (coloured arrows). Main categories of 
multi-vear products (REP/RAN}) makina use of these different tvpes of observations (white arrows)