Update of ECCO-GODAE

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Update of ECCO-GODAE
Tony Lee NASA Jet Propulsion Lab, California
Institute of Technology
In-situ observations
Satellite data
IGST-XII meeting, St. Johns, Newfoundland, Aug.
7-9, 2007
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Recent activities for the MITGCM adjoint-based
reanalysis system

• Update of almost all input data error
  estimates (e.g., weekly to daily SST).
• Injection of new data (e.g., time-varying GRACE,
  elephant-seal data).
• Extension through 2006.
• Replacement of surface-flux control with bulk
  forcing atmos. State control.
• Inclusion of full thermodynamic/dynamic sea-ice
  model.
• Downscaling e.g., Southern-Ocean
  eddy-permitting adjoint-based estimation.
• Fully global lat-long-polar cap grid.
• Mass-conserving (non-Boussinesq) option.
• OpenAD a new open-source tool for automatic
  differentiation.
• New ECCO web site.
• (not inclusive)

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Near real-time Kalman filter smoother system

• ECCO Kalman filter/RTS smoother ported to MOM4
  successfully.
• Core dynamics of MOM4 adjoint code completed.
• Downscaling tropical Indian Ocean Gulf of
  Mexico.
• Proposed transfer of ECCO-GODAE systems to
  PO.DAAC at JPL and to sustain the production and
  distribution.

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Example of recent ECCO activities
eddy-permitting adjoint assimilation
Model-data (SSM/I) misfit in sea-ice concentration
before assimilation
after 27 iterations of optimization
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Example of new input data CTD-type observations
from seals in SO

• Sea Mammal Research Unit,
• University St. Andrews, UK,
• British Antarctic Survey
• Courtesy M. Meredith

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Examples of applications by external users

• MIT Darwin Project (Follows et al.) drive
  biogeochemical model offline (N. Gruber).
• marine ecosystem modeling ocean biogeochemical
  cycle
• CLIMODE CLIvar MOe Water Dynamic Experiment
  (Marshall et al.)
• Investigation of sub-tropical 18o mode water
  formation dynamics
• CODAE Central California ODAE (C. Edwards, UCSC)
• Study of the Monterey Bay Central California
  coast circulation
• Sub-polar North Atlantic gyre tropical Pacific
  circulation (F. Schott, Geomar, Kiel)
• Long-term biogeochemical tracer calculations (S.
  Khatiwala, LDEO)
• Transport matrix (Jacobian) approach
• Mean Dynamic Topography uncertainties (F.
  Fossepoel, IMAU, Utrecht)
• Uncertainty estimate in preparation of the
  Gravity Field and Steady-State Ocean Circulation
  Explorer (GOCE) satellite mission
• Ocean circulation magnetic field signals (Manoj
  et al., GFZ, Potsdam)
• Liming the ocean inceases CO2 absorption (D.
  Harvey, U. Toronto)
• Uses upwelling velocities to investigate pCO2
  inceases in response to CaCO3
• Thermodynamic analysis of ocean circulation (N.
  Wienders, FSU J. Nycander, MISU, Sweden)
• Streamfunction-based calculations of MOC
  energetics
• Ocean mass changes and Earth rotation (B. Gross
  et al., IERS/SBO JPL)
• Global instability calculations (Shafer Smith,
  NYU)
• Global gravitational model development (N.
  Pavlis, SGT)

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Error/uncertainty estimates and updates remain
crucial, for new observations and model
representation
Examples of recent work

• Ponte, R. M., C. Wunsch and D.Stammer, 2007
  Spatial mapping of time-variable errors in
  Jason-1 and TOPEX/POSEIDON sea surface height
  measurements. JAOT, in press.
• G. Forget and C. Wunsch, 2007 Global
  hydrographic variability and the data weights in
  oceanic state estimates. J. Phys. Oceanogr., in
  press.
• D. Stammer and A. Koehl and C. Wunsch, 2007
  Impact of the GRACE geoid on ocean circulation
  estimates. JAOT, in press.

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New ECCO web page much more streamlined, better
documentation, more complete products.
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Various ECCO products (including input data,
surface forcing, and T/S budget output).
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Ongoing effort to develop an open-source
automatic differentiation tool Open AD