Chair: R. Wood

Rapporteur: G. Larnicol

Summary of Splinter Session 4:

Long Time Series (reprocessing/reanalysis physics and biogeochemistry)

7&8 Sep 2015 - CMEMS SE & UU Workshop, Brussels 1

CMEMS Service Evolution & User Uptake Workshop

CMEMS Multi-year products (MYP)

What are they?

• MultiYear Observations called ‘Reprocessed product’: produced by

theTACs with the objective to convert Copernicus satellite and in situ

observations into data products that: •support the MFCs with data required for assimilation and validation;

•provide useful observational data products to value-adding and end users.

• Multiyear Models called ‘Reanalyses product’: produced from ocean

models, constrained by available observations (data assimilation) • Spatially and temporally complete fields of ocean variables (T, S, currents, colour, nutrients,

simple ecosystem parameters)

•Annual ‘State of the Ocean’ report

Last 20-30 years

Produced every 3 years

CMEMS Multi-year products (MYP)

Possible application areas

•Environmental monitoring, e.g. for MSFD, MPAs •Put limited observations in context

•Estimate state in un-observed locations

•Define ‘prevailing conditions’

•Characterise time and space scales of variability to allow efficient targeting of observations

•Attribution •Assess drivers of observed changes/trends (to inform management measures)

•e.g. climate change, nutrification, fishing pressure, or just natural variability?

•Calibration of marine seasonal forecasts?

• Site/design studies for marine industry sector (O&G, renewal energy,...)

SST in NW Shelf regions, 1985-2012

Cefas Endeavour August 2010

European eel fishery 1900-2003

CMEMS Multi-year products (MYP)

Some questions for discussion

• Examples of successful use

• Barriers to use (and ideas to overcome them)

• What are the key variables for users?

• What resolution (time and space) are they needed on?

• What accuracy/precision is needed to make the products useful? How

do we assess the products?

• Time period for reanalyzed data sets (longer than 20/30

years), frequency of updates, need for near real time products ?

• What opportunities are on the horizon to improve observational inputs?

• Need to have several products lines, in particular dedicated to the

climate

• Link with Copernicus climate and atmospheric services?

CMEMS Multi-year products (MYP)

Some questions for discussion

• Examples of successful use

• Barriers to use (and ideas to overcome them)

• What are the key variables for users?

• What resolution (time and space) are they needed on?

• What accuracy/precision is needed to make the products useful? How

do we assess the products?

• Time period for reanalyzed data sets (longer than 20/30

years), frequency of updates, need for near real time products ?

• What opportunities are on the horizon to improve observational inputs?

• Need to have several products lines, in particular dedicated to the

climate

• Link with Copernicus climate and atmospheric services?

Topic 1: Examples of successful use /

Barriers to use

• Good feedback/experiences of use of Multiyear products:

REA in Baltic sea (salinity, trend, ice):

• Very useful material for their environmental applications

• Need to have time series much longer especially when addressing climate

signal (trend)

Calibration and Initialisation of models dedicated to seasonal forecasts

and/or decadal predictions

REA/REP (physical) are largely used by scientific community. A lot of

publications are based on these products. More difficult for the

biogeochemistry that seems less mature.

Topic 1: Examples of successful use /

Barriers to use

• Barriers/difficulties :

Resolution of the products too low

(ex: MED-MFC Biogeochemistry use to assess nutrient content along coast but

resolution of model not enough).

From a producer point of view: difficult to have quantitative feedbacks from the

users

General statement: to improve communication and access to the products:

• Organising dedicated workshop on the MultiYear Products (REA/REP)-

Challenge will be to get the users in the room

• Provide reference publications and in particular a DOI for each products

• Summary information describing the potential usage of the REA/REP (i.e.

Climate, O&G,...)

• Continue to improve the tools to access to the products. The large amount of

data could be a pb for users.

• Continue to improve the visualisation tools, try to ease the interface with

GIS)

Topic 2- What resolution (time and space)

are they needed on?

No unique answer, depend of what is need by the users BUT

Limits due to scientific aspects

• The ocean scales that are resolved are constrained by the observation

network available (deterministic). Could be mitigate by developing probabilist

approach.

• Resolution should be adapted to each region that have specific

characteristics (Rossby radius)

Answer also depends on policy aspects

• Need to better define the boundary between the Core service (CMEMS) and

Downstream community (intermediate users, national centers).

Topic 3- What accuracy/precision is needed

to make the products useful?

Need for communication about the quality/limit of the products • Information about the scales really solved (not only resolution of product) really expected

•Provision of addition information related to the REA/REP

Ex: increments and bias from the atmosphere system (ERA)

Continue to improve the methodology for evaluating the quality and consistency of the product. Suggestion to follow ISO framework to characterise the product quality (fitness for purpose)

If similar products are available, need to have a hierarchy for these products (which is the best for which applications ?)

Topic 4- Time period for reanalyzed data sets

Clear request to have longer period but issues:

C3S has the mandate to go back in time. – Coordination needed

between C3S and CMEMS

Lack of observations in the past:

This implies data rescue activities that should be coordinated between the different

Copernicus Services and existing data rescue initiatives

Despite less observation with lower accuracy, long time series of REA

products (>30y) still needed

Topic 5- What are the key variables for users?

Very short discussion

Need to have more observations if we want to extend the CMEMS catalogue to additional variables (especially for BGC variables)

Are the current BGC variables suitable for driving more complex ecosystem models ?

Strong demand for additional variables: lagrangian diagnostic , vertical velocity but some issues to be solved in particular the robustness of this variables