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Predictability of North Atlantic upper-ocean salinity (Work in progress ). Katja Lohmann, Daniela Matei , Johann Jungclaus, Manfred Bersch , Helene Langehaug and Yongqi Gao. NACLIM annual meeting 2014, Berlin. Motivation.
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Predictability of North Atlantic upper-ocean salinity (Work in progress) Katja Lohmann, Daniela Matei, Johann Jungclaus, Manfred Bersch, Helene Langehaugand Yongqi Gao NACLIM annualmeeting2014, Berlin
Motivation • Predictiveskillof subpolar upper-oceantemperatureforleadtimesoffivetotenyears due tonorthwardadvectionof warm (andsaline) subtropicalwater (Matei et al., 2012 *) • Similarideaforseasurfacetemperature in eastern Nordic Seas (talkby Helene Langehaug) * Matei, D., H. Pohlmann, J.H. Jungclaus, W.A. Müller, H. Haak and J. Marotzke (2012): Two tales of initializing decadal climate prediction experiments with the ECHAM5/MPI-OM model. Journal of Climate, 25, 8502–8523
Data • Initializedhindcastpredictionexperimentsfrom CMIP5 (so far MPI-ESM-LR); initializedeveryyear 1960 to 2010 • MPI-ESM-LR: • Northern grid pole in Greenland; horizontal resolution in North Atlantic • of 15 to 100 km • Upper-oceansaltcontent (0 - 500m) • CliSAPsalinitydataset: • combiningsalinityobservationsfrom different sources • Atlantic 30ºN - 70ºN ; 1951 - 2005 (3 yearrunningmeans) • MPI oceanmodelsimulationforcedwith NCEP/NCAR reanalysis
Conclusions (Work in progress) • Based on CMIP5 MPI-ESM-LR hindcasts: • Largestpredictabilityof North Atlanticupper-oceansalinity in western subpolar region; skillfullpredictable < 5 years • Predictabilitybased on initializedhindcastswellabovepredictabilityfrom transient 20C simulations; but not abovepersistenceforecast • Nopredictiveskill in eastern subpolar region due tohindcasts not capturing mid-1990s shift • High predictabilityalong STG/SPG boundary (German RACE project)
Outlook • Extendanalysisto CMIP5 modelsprovidinghindcastsinitializedeveryyear • NorCPMhindcastsifavailable in time • Comparewithresultsfrom MPI PreCMIP5 hindcasts(German RACE project) • Ishii salinitydataset (Japan Marine Science and Technology Center) tocoverentire Nordic Seas
Thank you! The research leading to these results has received funding from the European Union 7th Framework Programme (FP7 2007-2013) under grant agreement n.308299 (NACLIM).