glorys2: a global ocean reanalysis of the period 1992-present n. ferry, b. barnier, l. parent, g....
DESCRIPTION
3 1. IntroductionTRANSCRIPT
GLORYS2: A Global ocean reanalysis of the period 1992-present
N. Ferry, B. Barnier, L. Parent, G. Garric, C. Bricaud, C-E Testut, O. Le Galloudec, J-M Lellouche, E. Greiner, M. Drevillon, E.
Rémy J-M Molines, C. CabanesLEGI, Mercator Océan, Coriolis
2
1. Introduction: - GLORYS project overview- European context
2. GLORYS2 : an eddy permitting (1/4°) global ocean reanalyses of the « altimetric era »
- reanalysis system overview - results
3. GLORYS / MyOcean reanalysis meeting (June 2011): outcome
4. Conclusions and perspectives
Outline
3
1. Introduction
4
GLORYS project: National level
GLORYS: GLobal Ocean ReanalYses and Simulations
• French Reanalysis project, supported by GMMC (Mercator, Coriolis). PI: B. Barnier
• main partners: LEGI, LPO, LOCEAN, CNRM, CORIOLIS, MERCATOR• project started at national level in 2008• ARGO era reanalysis (2002-2008) produced in 2009 : GLORYS1V1
Objectif en 2011: • Achever la production de GLORYS2V1 (1993-2009) • Valider GLORYS2V1 et le run de reference MJM95 selon le protocole de validation commun MyOcean • Distribuer GLORYS2V1 et MJM95 • Quels défis pour les réanalyses ? organisation d’un meeting réunissant les utilisateurs et les producteurs de réanalyses océaniques.
6
GLORYS-1
GLORYS-2
Stream1: 2002-2008“ARGO”
Stream2: 1993-2007“altimetry”
T/S prof.: ~1000SST:1°x1° SLA: 2~3 satellites
T/S prof.: 2000~4500SST: 0,5°x0,5° 0,1°x0,1°SLA: 3~4 satellites
Number of Obs. / 7 days
GLORYS: different Streams
1992 2002 NOW
GLORYS1V1: produced and delivered to users early 2009 GLORYS2V1: produced and delivered to users early 2011
7
MyOcean project: www.myocean.eu.org
WP4: Global ocean reanalysis production & assessment Target: eddy permitting (1/4) global ocean reanalyses
Basic ingredients:• NEMO3 Ocean code, tuned for reanalyses, provided by CNRS• ERA Interim forcing• Reprocessed historical observations provided by TACs• Different data assimilation methods
• Ocean reanalyses: Ocean simulations constrained by reprocessed obs. CMCC, Mercator, U. Reading
• Ocean free simulation: CNRS• Ocean state estimation based on observations only: CLS
GLORYS reanalyses
Global ocean reanalyses at EU level
8
Two reanalyses versions are planed: V1 reanalysis: “June 2011” V2 reanalysis: “beginning 2012” (improved V1)
delivered products : monthly fields, T, S, U, V, SSH, Sea Ice (conc., thickness, velocity)
Documentation describing the reanalysis (strategy, implementation) Common CA/VAL protocol for reanalyses evaluation and assessment.
Global ocean reanalyses at EU level
MyOcean project: www.myocean.eu.org
Within WP4: Global ocean reanalysis production & assessment
9
2. GLORYS2V1: reanalysis system overview
10
Requirements for a global ocean/sea ice reanalysis
• Global ocean/sea-ice « eddy-permitting » circulation model: ORCA025.L75- NEMO OGCM (Ocean: OPA, sea-ice: LIM2_EVP)- Configuration set up by DRAKKAR consortium (Barnier et al, 2006, Drakkar group, 2007).
• Data assimilation system - Adapted from operational SAM systems used by MERCATOR-Ocean for
operational forecasts - SEEK Filter
• A delayed-time quality-controlled observations for assimilation - In-situ: CORA data base (Coriolis data center)- Altimetry: AVISO data base (CLS)- SST maps
GLORYS2: reanalysis system overview
11
Model: DRAKKAR ORCA025 configurationNEMO3.0/3.2 OGCM + LIM2 EVP Sea-Ice model:
Resolution: - Global 1/4° ORCA-type grid (1442x1021 grid points) - 75 vertical levels from 1 m at the surface to 200 m at the bottom for GLORYS2
Initialization: December 1991- Levitus 1998 climatology + Sea-Ice Concentration from NSDIC Bootstart products
Parameterizations: Filtered free surface, Partial step, Energy and Enstrophy conserving advection scheme, Isopycnal diffusion for tracers, Biharmonic for momentum, TKE turbulence scheme
Atmospheric forcing:- Bulk CORE Formulation (Large&Yeager, 2004)- ERA-Interim reanalysis products: 3 hourly for turbulent fluxes Daily for radiation (analytical diurnal cycle for solar)
In house correction of the radiation based on GEWEX satellites fluxes products.
12
SST spatial errors structures
SST (2002)model – RTG
Downward SW Flux 2002 ERAinterim - GEWEX
method to correct SW, LW Large Scale ERAinterim Fluxes with GEWEX
correction of ERA-Interim radiative fluxes
13
ERAInterim : (monthly running mean) daily mean ClimatologySatellite Obs : (monthly running mean) daily mean Climatology
Daily Climatology of corrective factor
Daily ERAInterim field: large scalex
Daily ERAInterim field: small scale
Daily Corrected ERAInterim: large scale +
Daily Corrected ERAInterim field
The correction is local, (i,j) grid point. Large scales correction only. Gewex climatology : 1999-2006; Indian Gap before. Gewex [40S-40N] : -3% SW and -6% LW (as Large
& Yeager 2004 for ISCCP) GPCPV2.1 Climatology:1997-2008. No correction northward 65N. No correction for ERAinterim climatology values
less than 1 unit (W.M-2 or mm.day-1).
• No change of interannual signal.• No change of synoptic patterns (cyclones).• The method can be applied outside the satellite period.
Method of correction
14
Correction of SW & LW
ERAI/GEWEX
ERAI/SW&LW corrected
ERAI
Large improvement with Gewex data
Same solution with corrected ERAinterim SW & LW fluxes
Errors remains in upwellings & large mesoscale activity areas.
Mean SST bias with SST RTG
FLUX ERA-Interim corrigés: utilisés à Mercator, LEGI, CNRM, IC3.CAT
15
DATA ASSIMILATION SYSTEM: SAM2v1, SEEK formulation
SEEK Filter :- Innovation is calculated at the First Guess at Appropriate Time (FGAT) approximation- Control vector comprises the barotropic height, T, S, U and V- Background error covariance calculated from an ensemble of 3D anomalies from a reference simulation-Adaptive error variance is consistent with innovation vector (a posteriori diagnostic)-The SEEK filter is weakly sensitive to the number of obs. to assimilate
3D-VAR Bias correction: for T and S
Incremental Analysis Updates (IAU): inserting increments over all model time steps smooth trajectory
GLORYS: DATA ASSIMILATION SCHEME
17
Delayed time observations for data assimilation
• Assimilated data : • Along track DT SLA (SSLATO/DUACS) : Jason-1, Jason-2,
Envisat, GFO, ERS1, ERS2, Topex/Poseidon
18
Delayed time observations for data assimilation
• Assimilated data : • Along track DT SLA (SSLATO/DUACS) : Jason-1, Jason-2,
Envisat, GFO, ERS1, ERS2, Topex/Poseidon• Reynolds AVHRR-only 0.25° SST,
19
Delayed time observations for data assimilation
• Assimilated data : • Along track DT SLA (SSLATO/DUACS) : Jason-1, Jason-2,
Envisat, GFO, ERS1, ERS2, Topex/Poseidon• Reynolds AVHRR-only 0.25° SST, • in situ temperature & salinity profiles (Argo network +
Xbts,CTDs, etc..) : CORA2.3 data base
20
2. GLORYS2V1 reanalysis : results
21
Reanalysis validation strategy
Validation protocol for reanalyses : MERSEA-GODAE metrics, CLIVAR/GSOP diagnostics, MyOcean quality control for operational systems adapted for reanalyses
6 types of diagnostics:CLASS1: computations are done on the model native grid. CLASS2: comparison of reanalysis products moorings, tide gauges and indexes (e.g. Nino boxes) comparisons CLASS3: Mean and variability of integrated quantities like transports (volume, heat, freshwater), sea ice extent, global/regional averages of various parameters (SST, SLA, sea ice concentration, …) CLASS4 : collocation of observation with model DATA ASSIMILATION DIAGNOSTICS: innovation statistics.EOFs analysis
22
Data assimilation diagnostics for T Global misfit average Global misfit RMS
No BIASRMS is stable
Results: GLORYS2V1 reanalysis : 1992-2009
ARGO is getting in
23
Data assimilation monitoring : SLA
1992 2009
GLORYS2V1 reanalysis results
No BIAS
RMS ~7cm
24
CLASS1 metric - difference with climatology
SST (0.5 m depth): difference with Levitus climatology
GLORYS2 REFERENCE: MJM95
Results: GLORYS2V1 reanalysis : 1992-2009
25
CLASS1 metric - difference with climatology
Temperature (at 100 m depth): difference with Levitus climatology
Results: GLORYS2V1 reanalysis : 1992-2009
GLORYS2 REFERENCE: MJM95
26
CLASS1 metric - difference with climatology
Salinity (at 0.5 m depth): difference with Levitus climatology
Results: GLORYS2V1 reanalysis : 1992-2009
GLORYS2 REFERENCE: MJM95
27
CLASS1 metric - difference with climatology
Salinity (at 100 m depth): difference with Levitus climatology
Results: GLORYS2V1 reanalysis : 1992-2009
GLORYS2 REFERENCE: MJM95
28
GLORYS2V1
Levitus et al., GRL 2005
Ocean Heat Content 0-700m
1022
JResults: GLORYS2V1 reanalysis : 1992-2009
29
Ocean Heat Content 0-700m
GLORYS2V1
Lyman et al. 2010
GLORYS2V1 reanalysisObservations only
1992 2009
Results: GLORYS2V1 reanalysis : 1992-2009
30
Ocean Heat Content 0-700m
Lyman et al. 2010
MJM95 reference simulationObservations only
1992 2009
Results: GLORYS2V1 reanalysis : 1992-2009
31
Ocean global heat budget
1992 2009
Levitus 1998 Climatology
GLORYS2V1
[0-2000m] global mean temperature
Mean temperature trend = + 0.5 W/m2
Results: GLORYS2V1 reanalysis : 1992-2009
32
SST trends
___ GLORYS: 0.10°C/decade- - - OBS. : 0.17°C/decade
Results: GLORYS2V1 reanalysis : 1992-2009
33
Sea level riseObs. (Altimetry)
Results: GLORYS2V1 reanalysis : 1992-2009
Mean sea level rise 2.8 mm/year
34
Arctic Sea Ice:Ice extent
SEA ICE EXTENT INTERANNUAL ANOMALIES
Correlation = 0.9
Results: GLORYS2V1 reanalysis : 1992-2009
35
Arctic Sea Ice Extent:September 1996 maximum
Results: GLORYS2V1 reanalysis : 1992-2009
36
Arctic Sea Ice Concentration
CLASS1 metric - difference with climatology
37
Arctic Sea Ice Extent:September 2007 minimum
Results: GLORYS2V1 reanalysis : 1992-2009
39
15 m zonal velocity
Under estimation of surface velocities
Still major flaws in the representation of equatorial undercurrents(the FREE RUN is far better)
CLASS1 metric - difference with climatologyResults: GLORYS2V1 reanalysis : 1992-2009
SVP drifter velocities are biased
Grodsky et al. GRL 2011
40
Comparison with Tide Gauges:
CLASS2 metric – local comparison with independent data
GLORYS2
GLORYS1
Results: GLORYS2V1 reanalysis : 1992-2009
41
GLORYS reanalysisRAPID-MOCHA measurements
= in situ observations (after, Bryden et al., 2005)
Maximum Atlantic MOC at 26.5°NResults: GLORYS2V1 reanalysis : 1992-2009
10
20
10
20
43
Quality Control on in situ data performed in GLORYS reanalysis:
Help to improve delayed time in situ data bases
“bad” Temp. profiles in 2009 “bad” Salinity profiles in 2009
Results: GLORYS2V1 reanalysis : 1992-2009
44innovation T profile
Obs.CLIMFCST
Obs.CLIMFCST
S profileinnovation
Quality Control on in situ data performed in GLORYS reanalysis:
Help to improve delayed time in situ data bases
Results: GLORYS2V1 reanalysis : 1992-2009
46
GLORYS users
> 40 users, data volume provided > 16 TBseveral research areas and application fields:
• Biogeochemical modelling (LSCE, Mercator)• Ecosystem modeling (CLS/MEMMS)• Sea Ice (LPO, Mercator)• TIWs (LEGOS)• pCO2 (NIES Japan, Bjerknes CCR)• Ocean circulation estimation and validation (CLS, SHOM)• Ocean Thermal Energy Conversion (EDF, Mercator)• Boundary / Initial conditions for regional modeling (CNRM, Infocean)• Mean Dynamic Topography inter comparisons (CLS, China)• MOC, MHT (RSMAS, UFRPE, CLS, Mercator)• South Atlantic circulation (NOAA)• Climate indexes, trends (IMEDEA, Spain)• Global ocean Mass budget (EOST/IPGS, NASA/GSFC)• object / animal drift (CLS, LPO, U. Texas, U. Hawai)• Hurricane (LEGI, CERSAT)• …
47
3. GLORYS / MyOcean reanalysis meeting in June 2011
48
Objective:The objective of this workshop is to gather the users and the producers of these reanalysis products, as well as other reanalysis products (e.g. MyOceanWP4, etc) in order :
to assess the scientific value of the reanalyses, to identify and prioritize ways of improvements of those products, to prepare the next generation of reanalyses
• 2-day meeting• ~ 30 participants• 17 oral presentation• discussions
GLORYS/MYOCEAN Workshop en Juin 2011 :
49
- Extend the reanalysis in the past (1979 present)- Assimilation of Sea-Ice data (concentration and velocity).- Improving of ORCA025 model (including tides).- Improving forcing (inter-annually varying runoffs, flux correction through data assimilation).- search for additional assimilation data (Tide gauges, SSS from SMOS, Aquarius, GRACE, etc.).- Links with the Green Ocean.- Improving the computing efficiency of the reanalysis system.- Partnership with decadal prediction community.- Feasibility of a global reanalysis at 1/12° with the ORCA12 model
Conclusions from GLORYS/MYOCEAN Workshop:
50
4. Conclusions & Perspectives
51
GLORYS2: Conclusions
GLORYS2V1 (1992-2009):résultats
1. capacité de production de réanalyse globales à méso-echelle: collaboration unique entre l’opérationnel (MERCATOR, CORIOLIS) et la recherche (LEGI, …)
2. production de la première réanalyse au niveau européen multi-données (SLA, SST, in situ) eddy resolving sur la période altimétrique.
3. résultats de très bonne qualité, GLORYS2V1 > GLORYS2V1.validation extensive dans un cadre international (MyOcean, Godae)
4. reconnaissance au niveau international, >40 utilisateurs, applications très variées.
52
GLORYS2: Perspectives
GLORYS2V2 (1992-2009): reanalysis is close to be finished
Improvements:
- ERA-Interim corrected precipitation with GPCPv2 observations- Iceberg melt parameterization in the Antarctic region - New MDT + new MDT errors from an objective analysis of 3 MDT products- On line Quality Control on of situ data temperature and salinity profiles- Assimilation of In situ profiles from sea mammals (T, S profiles) in the Antarctic (2004-2009)
→ Available beginning 2012.