The Copernicus Marine Service CMEMS global and regional ocean reanalyses

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1 The Copernicus Service CMEMS global and regional ocean reanalyses Towards a consistent set of high resolution ocean reanalyses for operational oceanography users and ocean state monitoring Marie Drévillon, Mercator Ocean on behalf of the Copernicus Service team Implemented by

2 Overview The Copernicus Service: a set of global and regional high resolution ocean reanalyses Results from the Copernicus Service reanalyses Ongoing work on uncertainty characterisation

3 The Copernicus Service in a nutshell A network of European producers From different European countries A large span of products and state-of-the-art European operational Products A unique catalogue of observations, reanalyses, near-real-time analyses and forecasts of the blue, white and green ocean ~150 numerical products A central information system to search, view, download products and monitor the system Currently ~7000 users worldwide

4 C M E M S p o r t o f o l i o g a t h e r s 1 4 m a r i n e p a r a m e t e r s PARAMETER MODEL SATELLITE (surface ocean) 25years in the past Today 10-day forecast 25years in the past INSITU Today 25years in the past Today Sea Surface Height x x x x x x x Temperature X X X X X X X Salinity X X X X X Waves X X X Currents/velocity X X X X X Mixed Layer Depth x x x x x Sea ice X X X X X Turbidity/Transparency X X Reflectance X X Nutrients x x x x Primary Production X X X x Oxygen X X X x Plankton x x x x Wind X X

5 C M E M S g a t h e r s 1 6 o c e a n r e a n a l y s e s 1 PHY 1 PHY 1 PHY 2 PHY ¼ daily 1 multi(4)-reana 1 PHY 2 PHY AMIP ERAi 1 PHY Current status: Altimetry era 1993-now Ocean Colour ERA for BIO 1997-now High resolution (<10km) in regions 80% use NEMO platform 3DVAR, SEEK + 3DVAR, EnKF 80% assimilate SST SLA and in situ (+ sea ice) 30% BIO assimilate Ocean Colour

6 C M E M S g a t h e r s 1 6 o c e a n r e a n a l y s e s 1 PHY 1 PHY 1 PHY 2 PHY 1 PHY 2 PHY See strategy document on marine.copernicus.eu 1 PHY Main objectives : Altimetry era 1993-now High resolution (<5 km) models Optimal use of obs. network Consistency with RT analysis (DA) BIO coupled or forced by PHY Agreement on validation metrics Maximum consistency in between regions Maximum cross use of CMEMS products

7 T h e 7 m o n i t o r i n g a n d f o r e c a s t i n g c e n t e r s

8 T h e C M E M S O c e a n S t a t e R e p o r t Written by 80 scientific experts from more than 25 European institutions, peer reviewed publication, the first ocean state report is a step forward into the development of regular annual reporting on the state and health of the global ocean and European regional seas based on Copernicus Service products. Including CCI products disseminated by CMEMS More information: Issue #2 under review

9 Evaluation of ocean reanalyses See poster by Garric et al. Independent current meters from TAO/TRITON (in situ TAC) V3 Current V4 OBS RMS < 0.3 m.s -1 Underestimation of EUC (Equatorial Under Current) Continuous improvement since the beginning of GLORYS -> data assimilation & mean dynamic topography

10 J1 High resolution global reanalysis GLORYS12 First results from GLORYS12 SLA horizontally averaged residual = observation analysis RMS differences J2 See poster by Lellouche et al. GLO ¼ NRT GLORYS ¼ RAN ( ) GLO 1/12 V1 NRT GLO 1/12 V2 NRT GLORYS 1/12 RAN ( ) GLO 1/12 V3 NRT 2007-now

11 High resolution IBl reanalysis vs GLORYS Comparisons with CMEMS regional reanalyses : upgraded physics and higher resolution improve physical processes -> Continuous improvement «feedback loop» between CMEMS regional and global reanalyses -> towards higher resolution in both regional and global reanalyses GLORYS ¼ IBIRYS 1/12 Observation of Biscay Coastal jets from Batifoulier et al (2012) APR MAY JUN IBIRYS SSH low frequency correlation at tide gauges Courtesy of Bruno Levier GLORYS 2002

12 H i g h r e s o l u t i o n B A L r e a n a l y s i s v s o b s e r v a t i o n s Bottom Bio simulation at BY5(55.25,15.98) Averaged Bio simulation during the period at BY15(57.33, 20.05) Courtesy of Liu Ye et al

13 M E D s e a r e a n a l y s i s 1/16 physical reanalysis starting in (CMCC) Biogeochemical reanalysis with assimilation of Ocean Colour observations (OGS) Courtesy of C. Fratianni et al Long term: higher resolution coupling with Black Sea reanalysis

14 U ncertainty characterisation Intercomparison/validation to assess uncertainties among ocean reanalyses (model errors and bias, observing system reliability over time) GODAE/CLIVAR/GSOP ORA-IP, Balmaseda et al (2015) JOO Multi ORA NRT intercomparison, Xue et al (2017) Clim. Dyn. CMEMS multi-reanalysis ensemble product GREP based on ORCA025 GLORYS/C-GLORS (CMCC)/GLOSEA5 (UKMO)/ORAS5 (ECMWF) Intercomparison of high resolution reanalyses is planned (HYCOM and GLORYS12) Evaluation of Ocean Syntheses COST Action Ensemble modelling and data assimilation: Stochastic perturbations ensemble data assimilation GLORYS (at ¼ ) planned for 2020

15 Assessing uncertainties on OMIs with GREP Heat content using GREP ensemble mean + CORA + ARMOR3D shading = where signal > spread See poster by Jackson et al. (AMOC), and Zuo et al (Sea Ice) Figures and results from the Ocean State Report #2, under review at JOO See poster by Storto et al (steric height), and Drevillon et al (T, S, U, V)

16 Assessing uncertainties at regional scale Intercomparisons in progress on common regions : IBI/MED NWS/BAL GLO/ARC Multi-reanalysis product using up to 6 product on the NWS area 1 NWS, 1 IBI, 2 IMR, 1 PML, 1 NOC Courtesy of M. Tonani et al

17 Conclusions Global and regional reanalyses and uncertainty estimates are available from the Copernicus Service CMEMS Powerful tool for ocean monitoring necessary reference for all NRT applications Towards more consistency with NRT analyses (HR, observing system shape) -> requested by CMEMS users Intercomparison and ensemble approaches are favored to provide uncertainty estimates, international HR reanalyses intercomparisons are planned Short to mid term perspectives: higher resolution, more assimilation of Ocean Colour observations, reanalyses for waves Many challenges (high resolution atmospheric forcing, ocean-atmosphere-wave-ice coupling, river runoffs, extension in the past, climate monitoring) to be tackled in partnership with Climate Change Service More details on our posters (GLORYS 1/12, GREP etc.)!

18 A COST Action to improve the coordination of European efforts in the evaluation of ocean syntheses: better understanding of the value and use of ocean syntheses promote the use of ocean syntheses Chairs: Aida Alvera-Azcárate (University of Liège, BE) Keith Haines (University of Reading, UK) a.alvera@ulg.ac.be Earth System Science and Environmental Management

19 High resolution global reanalysis GLORYS12

20 Users requests about reanalyses Longer time series (30 years) [to assess climate trends] Need of reanalysis close to present time Ocean monitoring activities: Ocean State Report, Indicators Need of atmospheric forcing data used in the reanalysis Climatological products derived from the reanalysis products Waves in reanalysis Expected in 2018 Need of reanalysis compliant and in continuity to real time products Global reanalysis at a resolution higher than 0.25 degree Guidelines for the use of the multiple reanalysis products Collaboration with C3S Objective 2020: NRT-1 month in interim mode OSR#1 in 2016 Collaboration with C3S Expected in 2018 Expected in 2018 Expected in 2018 Continuous improvement of QUIDs, intercomparisons

21 Example of GLORYS global reanalysis The project started in 2006, led by Nicolas Ferry and Bernard Barnier (CNRS) Use of NEMO ORCA025 + LIM, strong pan-european collaboration Forced with ERA-interim reanalysis (large scale correction of rainfall and radiative forcing) and climatological runoffs Multivariate assimilation of SST, SLA, in situ T/S profiles (and monovariate for Sea Ice since 2011) consistent with what is done for global real time analysis 3D T and S restoring to climatology at Gibraltar strait, Bab el Mandeb strait, and south of 60 S below 2000m No SSS or SST restoring Focused on the altimetry era: 1992-now Evaluation protocole from GODAE/GSOP/ORA-IP

22 Surface equilibrium in GLORYS surface heat fluxes trend (-0.3 W.M 2 ) ilargely explained by the positive evaporation trend (+2.2mm/year). Net Surface Heat Fluxes Sea Surface Temperature See poster by Garric et al. Net Mean Surface Heat Uptake : + 0.5W.M 2 Trend of evaporation : +2.2 mm/year. Trend of surface net heat flux : -0.3 W.M 2 /Year Comparable to PMWC evap trend 2.35 mm/year