Performance against assimilated data

GLORYS2V4 in CMEMS

Surface Ocean Heat Uptake

� 3D gridded descriptions of the state of the ocean at ¼°resolution and 75 vertical levels

� Long time series over the altimetry era 1993-2016, well documented quality, regular updates

� Daily mean of essential variables (Temperature, Salinity, Sea Surface Height, Current, Sea ice)

� Similar reanalysis at 1/12°°°°resolution will be available in 2018.

Performance and Quality Assessment of the Global Ocean Eddy-Permitting Physical Reanalysis GLORYS2V4

G. Garric, L. Parent, E. Greiner1, M. Drévillon, M. Hamon, JM Lellouche, C. Régnier, C. Desportes, O. Le Galloudec, C. Bricaud, Y. Drillet, F. Hernandez, C. Dubois, O. Hernandez and P-Y. Le Traon

Mercator Ocean,1CLS.

Core of the GLORYS Reanalysis System

Sea Level Rise

Ocean State Report 2016

contact: ggarric@mercator-ocean.fr

References:

• Evaluation of the global mean sea level budget between 1993 and 2014, Chambers et al., 2017, Surv. Geophys.

• Arctic Arctic Ocean basin liquid freshwater storage trend 1992–2012, Rabe et al., 2014, Geophys. Res. Let.

• More results of Glorys2v4 in : CMEMS Ocean State Report #1, von Schuckmann et al., 2016 , J. of Oper. Oceanog.

CMEMS: Copernicus Environment Monitoring Service ; products, available for download at marine.copernicus.eu

Surface heat equilibrium is less than 1 W.M2.

The negative trend of net surface heat fluxes (-

0.3 W.M2) is largely explained by the positive

evaporation trend (+2.2mm/year).

Previous Version (GLORYS2V3)

Runoff (rivers): Dai & Trenberth (2002)

EmP=0 (Mass surface budget)

Initial conditions (T,S) from Levitus (1998)

3D (T,S) damping south. 60°S and below2000m depth. No SSS or SST restoring .

Large scale correction of rainfalls and radiative fluxes towards resp. GPCPV2.2 &

GEWEX SRB3.0.

Hybrid MDT CNES-CLS 09

CORA3.3 in situ data base

Assimilation of sea ice from CERSAT

GLORYS2V4

Idem but Dai & Trenberth (2009) + Greenland and Antarctica’s freshwater fluxes

Idem + Mass surface budget = +1.74mm/yr

Global mean of steric* increment=0

Initial conditions (T,S) from EN4 (90’s)

Idem + damping in Gibraltar and Bab-El-Mandebstraits.

Idem but Large scale correction of rainfallstowards PMWC

Hybrid MDT CNES-CLS 13

CORA4.1 in situ data base

Idem.

The New System GLORYS2V4

Temperature 1993-2015 1993-2005 2005-2015

0-100m 0.78 0.87 0.68

100-300m 0.69 0.77 0.61

300-800m 0.43 0.49 0.36

800-2000m 0.18 0.24 0.12

Trend (mm/yr)[0m-Bottom]

GLORYS2V4 (1993-2015)

Chambers et al. (2017) (1992-2014)

Total steric* 1.6 1.2 ± 0.23

Thermosteric 1.8 1.2 ± 0.23

Halosteric -0.2 ~0

Total mass 1.74 1.8 ± 0.46 (1992-2013)

Sum of components 3.34 3.0 ± 0.52

GMSL* (GIA* corrected) 3.56 3.19 ± 0.63

Time series of maximum Atlantic Meridional Overturning Circulation at 26°N from GLORYS2V4 in blue and the

RAPID array in red. (10 days running mean (thin line) and 3-month running mean (thick solid line).

Model/Configuration� NEMO3.1

� ¼° resolution & 75 z-levels.

� LIM2 sea ice model:

� Atmospheric forcing : ERA-Interim (3H) – Bulk Formulation.

� Bathymetry: ETOPO+GEBCO

� Runoffs: seasonal climatology(120 rivers).

Assimilation� SAM2 (Singular Evolutive

Extended Kalman filter ) / 3D-FGAT innovation (First Guess at Appropriate Time) / IAU (Incremental Analysis Update)/ Local 2D Technic.

� 3D-VAR Large Scale (T,S) biases Correction

� Assimilation of sea iceconcentration

Observations� SST (1/4°) from AVHRR+AMSRE

� Altimetry (T/P, Envisat, Jason, Cryosat2, …)

� In situ (T,S) (Argo) from CORA (CMEMS) data base

� Hybrid Mean DynamicalTopography (MDT)

TemperatureTemperature SalinitySalinity

Satellite

Data

In Situ

Data

Salinity 1993-2015 1993-2005 2005-2015

0-100m 0.21 0.25 0.16

100-300m 0.11 0.13 0.09

300-800m 0.06 0.07 0.05

800-2000m 0.03 0.04 0.02

AltimetryAltimetrySea Surface

Temperature

Sea Surface

Temperature

Arctic Sea Ice ConcentrationArctic Sea Ice Concentration Antarctica Sea Ice ConcentrationAntarctica Sea Ice Concentration

Comparisons with independent dataComparisons with independent data

� Steric sea level dominated by upper layers thermosteric

signal

� Slight overestimation of the GLORYS2V4 thermosteric

component compared to recent estimates and in situ data

� GLORYS2V4 estimations inside the errors bars of

observations

GMSL: Global Mean Sea Level GIA:Glacial Isostatic Adjustment.

Steric signal : volume (dilatation/contraction) change due to density change.

GMSL: Global Mean Sea Level GIA:Glacial Isostatic Adjustment.

Steric signal : volume (dilatation/contraction) change due to density change.

Thermosteric from GLORYS2V4

Halosteric from GLORYS2V4

Thermosteric from CMEMS in situ data

Thermosteric from GLORYS2V4

Halosteric from GLORYS2V4

Thermosteric from CMEMS in situ data

Mean Zonal

Surface Currents

� Good accordance with surface

drifters data from CMEMS In Situ

TAC (Thematic Assembly Center)

� Shortcomings in equatorial

dynamics (Western Pacific)

Large Scale Dynamics Meridional Overturning

� Good accordance with RAPID array

in interannual variability

� Glorys2v4 and observations are

correlated at 0.86.

� No long-term trend in Glorys2V4

estimate.

Changing Arctic Ocean

Freshwater Content (FWC)

� Comparisons with poorly sampled

area and non assimilated data

� Very good accordance with in situ

data from Rabe et al. (2014)

� Large increase of FWC from mid-90’s

to 2008.

Blue: rms with in situ sea surface temperature dataBlue: rms with in situ sea surface temperature data

Net Mean Surface

Heat Uptake :

+ 0.5W.M2

Mean SST :

18.27°C.Net Surface Heat Fluxes

Sea Surface Temperature

Net Surface Heat Fluxes

Sea Surface Temperature

Sea Ice Extent

Glorys2V4

CMEMS Products

(not assimilated)

Glorys2V4

CMEMS Products

(not assimilated)

Arctic OceanArctic Ocean AntarcticaAntarctica

Arctic Ocean

- 85000 km2/Year

Antarctica

+ 42000 km2/Year

20072007

20122012 20162016

1995 2000 2005 2010 2015

1995 2000 2005 2010 2015 1995 2000 2005 2010 2015

1995 2000 2005 2010 2015