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Summary 26 September 2012 Core Theme 2: Assessing sources of uncertainty in ocean analyses and forecasts Lead: Steffen M Olsen (DMI), Co-lead: H. Drange (NERSC) Participants: UiB , GEOMAR, UPMC-LOCEAN, MET-O, NERSC, DMI, MPG. THOR 2012. CT2: Assessing sources of uncertainty….
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Summary 26 September 2012 Core Theme 2: Assessing sources of uncertainty in ocean analyses and forecasts Lead: Steffen M Olsen (DMI), Co-lead: H. Drange (NERSC)Participants: UiB, GEOMAR, UPMC-LOCEAN, MET-O, NERSC, DMI, MPG
THOR 2012 CT2: Assessing sources of uncertainty… Collaborative work: Paper on the historical hosing experiments now online - Swingedouw et al. 2012, Clim. Dyn. New coordinated sensitivity simulations using RCP8.5 scenarios completed - Five model-member ensemble. Analysis and interpretations initialized - CT2 hands-on workshop in Paris, May 2012. Developments: New model based estimate of plausible future GIS mass loss available from MPI Deliverables months 48 D34 WP2.1 : Updated evaluation of ocean state estimates (CT3 obs) D35 WP2.2 & 2.3 : Recommendation of model developments to improve future THC forecasts D34 concludes also on D04 (ongoing throughout the project) CT2 overview, Hamburg
THOR 2012 RCP8.5 hosing experiments • Setup and models • RCP8.5 over the period 2006-2100 • 0.1 Sv distributed around Greenland for the period 2050-2090 • Four models: • EC-Earth, MPI-ESM, HadCM3, IPSLCM5A-LR, BCM2 Hosing relative to 2050 Hosing-RCP8.5 CT2 overview, Hamburg
THOR 2012 AMOC response to hosing CT2 overview, Hamburg
THOR 2012 Preliminary conclusions • Smaller impact than under historical (and Stouffer et al. 2006) but not negligible: around 1 Sv at 26°N (1.5 Sv for the max) in 40 years. (equivalent to around 0.05 PW decrease at 26°N in HT) • Deep convection already ceased south of the GSR (Labrador Sea) in all model by year 2050. • In the strongly forced experiment (RCP8.5) the deep ocean apears decoupled and the ocean impact of hte hosing is confined to the upper ~ 800m • Apparently reduced AMOC sensitivity to GrIS melting in a warming climate! CT2 overview, Hamburg
THOR 2012 Greenland's response and interaction within a fully coupled ice sheet-earth system for the near-future Christian Rodehacke, Miren Vizcaino, Uwe Mikolajewicz • ESM: ECHAM6 T63/MPIOM GR15 (T63L47GR15L40) • Ice sheet model: mPISM (SIA+SSA)Greenland: Resolution horizontal 10 km, vertical 40 m • Ctrl: Control Run for pre-industrial state: pCO2=284ppm • abrupt: immediate increase to 4xpCO2 • 1pct: Gradual pCO2 increases by1% per year until 4xpCO2, then constant • 1pct_alone: same as 1pctbut ice sheet melt water is from Ctrl CT2 overview, Hamburg
1pct Ctrl THOR 2012 GrIS melting under global warming Ice thickness1pct – Ctrl : 350yr grow Ice mass loss rate (mSv) Ctrl 1pct Thickness anomalies (m) abrupt 0yr 200yr 350yr shrink Equilibrium lines Ctrl, abrupt, 1pct, 1pct_alone CT2 overview, Hamburg
THOR 2012 GrIS melting under global warming AMOC Ctrl Stronger radiative forcing results ultimately in a weaker AMOC In the first 200yr the additional melt water hardly affects the AMOC 1pct_alone 1pct abrupt CT2 overview, Hamburg
THOR 2012 CT2 activities will continue after Thor • - joint analysis and publication on the RCP8.5 exercise. • intercation with CT3 on exploiting Thor observations in ocean state estimates and analysis. • Note the CT2 multi model data archive of historical and RCP8.5 hosing experiments. CT2 overview, Hamburg
THOR is a project financed by the European Commission through the 7th Framework Programme for Research, Theme 6 Environment, Grant agreement 212643 http://ec.europa.eu/index_en.htm