Drakkar

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NEMO and Ocean Reanalysis

• Ocean Model Strategy in UK now focussed on NEMO
  (MetOHadley, ECMWF, Reading, NOC, POL, UEA)
• Rapid Climate change project
• Greg Smith
• Ben McDonald (PhD) (Historical and Rapid array
  focus)
• NOC collaboration Brian King (ARGO focus)
• Ocean Reanalysis at 1? and ¼?
• Special project time at ECMWF
• Can also run on Reading Cluster (57/64 processors
  for ¼ )
• Developing e-Science access to POLBAS clusters
  (400 proc)

NEMO ¼ output from compute cluster
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Developing NERC Grid
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Biogeochemical modelling

• Collaboration with UEA, NOC and Met Office
• 2? or (1? future) global NEMO with
  biogeochemistry
• Carbon cycle modelling
• NPZD v. PFT modelling Planktom5 has 3 PFTs
  BacteriaNutrients 29 prognostic variables
• Currently NEMOv1 (moving v2)
• Implement physical data assimilation to
• Correct physical model biases
• Explain inter-annual variability in bio-carbon
  measurements eg. AMT
• Semi-prognostic v. Full Assim. gt Greg

Mixed Phytoplankton Chlorophyll (mol/l)
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Arctic Ocean modelling for IPY (future)

• Greg already involved in EU Damocles IPY project
  (1 year)
• UK IPY project ASBO (Arctic Shelf and Basinwide
  Oceanography)
• Collaboration with UCL (PI Seymour Laxon), NOC
  (Sheldon Bacon) and Met Office
• Should start spring 2007. New Post Doc needed
  !!!!!!!!!!!!!!!!!!
• ASBO will extend assimilation methods for Arctic
  seas
• Assimilate hydrography data from IPY Arctic
  cruises, especially Canadian CAME Circum
  Shelf-break cruise
• Extend Gregs work to include Altimeter
  assimilation (using ERS, ENVISAT and preparing
  for Cryosat 2 data) using Laxons work on sea ice
  drafts from altimetry
• Aimed at Arctic shelf ? Arctic basin? N Atlantic
  freshwater budget
• Expect to use 1 and ¼ NEMO models
• Possibly using CICE going into NEMO (UCL)
• Compare with Inverse models (NOC Navaro Gab)

Click to Apply
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Relevant questions
Main aim

• Can we recover water mass variability and THC
  changes using data assimilation?
• How can we best use the available observations?
• What does the data assimilation tell us about
  model errors?

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How can we best make use of the available
observations?
Two types of variability dynamic and that due to
water mass changes
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NEMO Plans and progress...

• Strategy
• Use 1o model for testing the assimilation scheme
  and to perform multiple sensitivity studies.
• Then transfer assimilation scheme to 1/4o global
  model to produce high-resolution reanalysis.
• Current Status
• 2, 1 and 1/4 resolution global NEMO
  ice-ocean models set-up and running, both at
  ECMWF and ESSC cluster.
• Several 45 year hindcasts of 1 NEMO complete.
• Generalized observation operator has been
  implemented in NEMO
• Can now begin implementing assimilation system

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NEMO in Google Maps/Earth

• It works!!
• But still needs some adjustments
• Click below (best with Firefox)
• http/lovejoy.nerc-essc.ac.uk8080/ncWMS/godiva2.
  html
• Please note NEMO output should be made CF1.0
  compliant NetCDF !

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NEMO in GoogleEarth

• http//lovejoy.nerc-essc.ac.uk8080/ncWMS/godiva2
  .html