CLIVARGSOP Activities

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CLIVAR/GSOP Activities

• Detlef Stammer
• SSG-15
• Sept. 11-14, 2007

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SSG-14 Actions for GSOP

• GSOP to identify and and coordinate development
  of CLIVAR reference data sets, including error
  bars where possible, and develop ideas on how to
  make them widely accessible.
• Develop common climate indices for
  models/observations as component
• Develop plans for an "OceanObs 200X" and consult
  potential sponsors regarding sponsorship. To be
  seen as part of CLIVAR annual workshop devoted to
  the Oceans' role in climate include issues such
  as Ocean Obs Data Centre, measurement of ocean
  currents and transports, etc. (GSOP)

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GSOP-2La Jolla, CA, USA08 - 09 December 20006

• Global Carbon and Synthesis needs (Chris Sabine)
• Arctic Ocean / IPY (Vladimir Ryabinin)
• OOPC/CLIVAR climate indices (Albert Fischer)
• Start plans to develop a small pilot project for
  joint synthesis activities between GSOP and
  Carbon community (D. Stammer, C. Sabine)
• GSOP to start planning with ocean
  synthesis/reanalysis groups on the assimilation
  of IPY-generated dataset (D. Stammer, A. Weaver)
• Prepare a data requirements document with
  identification of needs and suggestion of
  specific tasks (D. Legler, D. Stammer)
• Draft a white paper on the societal relevance of
  the ocean observing system and circulate to panel
  for comments (D. Roemmich, D. Stammer)
• GSOP co-chairs to write to Alex Ganachaud and
  Rick Lumpkim inviting them to develop the
  rationale for an ocean velocity workshop (GSOP
  co-chairs)

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GSOP Contributions to Cross Cutting Topics

• Anthropogenic Climate Change
• A pilot project will be developed between GSOP
  and the carbon community for incorporating carbon
  and tracers in synthesis efforts. Members of the
  carbon community have attended the CLIVAR/GODAE
  Ocean Synthesis meeting in 2006 and initiated
  this interaction.
• A Hydrography Advisory Group has been formed,
  co-sponsored by GSOP, IOCCP and the SOLAS/IMBER
  Carbon group. This group will hold its first
  meeting in November.
• GSOP intends to appoint a member of the carbon
  community to the GSOP panel to help facilitate
  the interaction.
• GSOP is starting a pilot project for a joint
  synthesis of physical and carbon data. A first
  planning meeting is scheduled for end of November
  in Hamburg (C. Sabine, D. Wallace, D. Stammer).

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Decadal Predictability

• Ocean synthesis products are an important tool
  for identifying and understanding decadal ocean
  variability of some processes.
• The GSOP ocean synthesis evaluation effort tests
  methods and products which can contribute to
  studies of decadal variability.
• First studies exist, that use 50 year or shorter
  synthesis results to analyse space and time
  scales of, e.g.,MOC changes in the Atlantic and
  to identify causes for those changes.
• Next generations decadal and 50-year global
  syntheses are now being undertaken that are truly
  global and include improved ocean mixing physics.
  
• Simultaneously it will be attempted to be
  up-to-date with new estimates so that at the time
  of the AR5, those new fields can be used for the
  initialization of coupled models.
• Work on testing the improvement of coupled model
  forecasts through the use of ocean syntheses has
  started and shows first promising results.
• Simultaneously, discussions have started to enter
  coupled assimilation approaches.

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Example GECCO State Estimate

• Ocean synthesis, performed over the period 1952
  through 2001 on a 1º global grid with 23 layers
  in the vertical, using the ECCO/MIT adjoint
  technology.
• Model started from Levitus and NCEP forcing and
  uses state of the art physics modules (GM, KPP).
• The models adjoint (obtained using TAF) is used
  to bring the model into consistency with most of
  the available ocean observations over the full
  period by adjusting control parameters.
• At this stage control parameters are the models
  initial temperature and salinity fields as well
  as the time varying surface forcing, leading to a
  dynamically self-consistent solution (next step
  is to include mixing).

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Comparison of maximum MOC at 25N
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Southward Propagation of anomalies of maximum
MOC Southward propagation of anomalies of
maximum MOC in the North Atlantic from GECCO
(left) and from MOC sensitivity study (right)
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Sea Level Rise

• Studies are now underway, analysing sea level
  changes on regional and global scale as they
  emerge from synthesis results. Results confirm
  earlier ones based on data alone stating that
  most of the observed sea level changes are
  thermosteric in nature. However, synthesis
  results indicate that the underlying changes in
  heat content are caused by the changing wind
  field and an associated redistribution of heat in
  the ocean. This seems to hold especially for the
  last 40 years. Considering the last decade,
  however, the change in surface heat flux seems to
  gain importance in the northern hemisphere.

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Cooperation with IGBP projects

• Close discussion about a pilot synthesis project
  and appointment of member of the carbon community
  on the GSOP panel.

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International Polar Year

• GSOP encouraged ocean synthesis groups to prepare
  a special IPY-period ocean synthesis, using the
  additional polar data generated during IPY.
• Attempts are underway now to include the full
  Arctic in new synthesis efforts which will use
  all data available there, including those from
  the IPY.
• A major obstacle here is the assimilation of ice
  data which urgently needs to be address to make
  progress in global synthesis and initialization
  attempts.
• The next GSOP synthesis meeting at MIT will
  address this topic.

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German Consortium
The North Atlantic as part of the Earth System
The path from understanding the system to
regional impact analyses.
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Regional Consortium FociNorth Atlantic,
including key regions of tropical and subarctic
ocean
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North Atlantic Synthesis Activities

• North Atlantic ECCO adjoint model, incl. Arctic
  and sea ice.
• 1/6 degree resolution.
• Assimilation of all data, including CFCs.
• Mixinbg as control parameter.
• Nested in global GECCO results.
• First 1992 to present
• Later 50 years.

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International Hydrography Advisory Group

• International Repeat Hydrography and Carbon
  Workshop (Japan in November 2005), recommended
  that an International Hydrography Advisory Group
  be established
• Aim bring together interests from physical
  hydrography, carbon, biogeochemistry, Argo,
  OceanSITES, and other users and collectors of
  hydrographic data,
• Task - to develop guidelines and advice for the
  development of a globally coordinated network of
  sustained ship-based hydrographic sections that
  will become an integral component of the ocean
  observing system.

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International Hydrography Advisory Group

• MEMBERSHIP
• Masao Fukasawa (JAMSTEC)
• Bernadette Sloyan (CSIRO)
• Greg Johnson (NOAA PMEL)
• Niki Gruber (ETHZ)
• Chris Sabine (NOAA PMEL)
• Arne Koertzinger / Toste Tanhua (IFM-GEOMAR)
• Secretariat will be provided by Nico Caltabiano
  (ICPO)
• and Maria Hood (IOCCP)

The group is aiming to first meet on 1-2 November
in Victoria, Canada, during the Annual PICES
Meeting. After that it will mainly work by email.
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International Hydrography Advisory Group
Draft Terms of Reference I. To develop the
scientific justification and general strategy for
a ship-based repeat hydrography network, building
on existing programs and future plans, that will
constitute the core global network, post-CLIVAR
considerations should include a) a set of basic
requirements to define a coordinated repeat
hydrography network (e.g., sample spacing,
repeat frequency, recommended core
measurements, etc.) b) an inventory of
existing and planned sections that meet those
criteria c) an assessment of other observing
programs that can either contribute to or use
hydrography data (e.g., Argo, OceanSITES,
GeoTraces, etc.) d) an assessment of data
release needs to meet research and operational
objectives e) an inventory of on-going or
planned scientific synthesis activities (basin
and global) that might benefit from closer
collaboration f) guidelines for the transition
from the CLIVAR hydrographic program to the new
system, including sections, data and information
management, and synthesis activities. II. To
develop guidelines for a single global
information and data center for ship-based repeat
hydrography III. To review and provide
guidance on the need to update the WOCE
hydrographic manual, including a review and
update of data quality control issues.
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Issues for the SSG

• After the International Hydrography workshop,
  held in Shonan Village, Japan, in November 2005,
  it has been recommended the change of name for
  the CLIVAR/Carbon Repeat Hydrography Programme to
  
• International Repeat Hydrography and Carbon
  Programme.
• This change of name has been accepted by the GSOP
  and should be endorsed by the SSG.

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Issues for the SSG

• Dean Reommich as co-chair was replaced by
  Bernadette Sloyan. Dean continues to stay on the
  panel.
• Detlef Stammers term as co-chair ends end of 07.
  If considered useful by the SSG, he could/would
  stay on for 2 more years (through OceanObs09).
• GSOP recommends that the panel should have a
  carbon representative, like the ocean basin
  panels. IOCCP has made an indication for names.
• GSOP recommends to have a CliC representation on
  GSOP.
• Moreover, GSOP suggests to have a data person on
  the panel.
• Suggested membership replacements
• Phil Arkin Jeff Key
• David Anderson Keith Haines
• Neville Smith Toste Tanhua
• Victor Zlotnicky Sylvie Pouliquen

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Expected legacy at the end of CLIVAR (2013)

• An integrated mechanism for planning and
  collection of hydrography data, in association
  with the carbon community.
• Climate data stream
• Sustained ocean synthesis capabilities, possibly
  in coupled ocean-atmosphere-ice models.
• Capabilities to initialize ocean-atmosphere-ice
  coupled models through ocean syntheses to improve
  decalda predictions.
• Synthesis products

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New activities being planned

• Second CLIVAR/GODAE meeting on Synthesis (24-25
  September 2007, MIT, USA
• First hydrography Advisory group meeting (1-2
  November 2007, Victoria, Canada)
• Velocity Workshop, 8-9 December 2007, SIO, USA
• 3rd Panel Meeting, 13-14 March 2008, NOCS,
  Southampton, UK
• OceanObs 09, to be run jointly by GSOP and OOPC
  (see extra document).
• Upper ocean thermal review with emphasis on XBT
  lines. Date TBD, but before OceanObs09.
• Pilot CLIVAR/carbon synthesis effort.
• 3rd Reanalysis Conference (Jan. 08)

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Ongoing Synthesis

• Several global ocean data assimilation products
  are available today that in principle can be used
  for climate applications.
• Underlying assimilation schemes range from simple
  and computationally efficient (e.g., optimal
  interpolation) to sophisticated and
  computationally intensive (e.g., adjoint and
  Kalman filter-smoother).
• Intrinsically those efforts can be summarized as
  having three different goals, namely
• climate-quality hintcasts,
• high-resolution nowcasts, and
• the best initialization of forecast models.

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Some details about legends
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Challenges

• This spectrum of applications of ocean synthesis
  for climate variability and prediction purposes
  spans over seasonal-to-interannual,
  decadal-to-centennial, and even millennial time
  scales.
• These applications pose a range of accuracy and
  robustness requirements on ocean reanalyses.
  Consequently, they necessitate somewhat different
  data assimilation approaches and evaluation.

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GSOP/GODAE Synthesis Evaluation Workshop,
Aug.31,Sept. 1, 2006 at ECMWF.

• The overall goals of the inter-comparison of
  global synthesis efforts are to
• Evaluate the quality and skill of available
  global synthesis products and determine their
  usefulness for CLIVAR.
• Identify the common strength and weakness of
  these systems and the differences among them, as
  well as to identify what application can be best
  served by what synthesis approach.
• Define and test climate-relevant indices that in
  the future should be provided routinely by
  ongoing or planned synthesis efforts in support
  CLIVAR and of the wider community.
• Define climate data standards required for CLIVAR
  syntheses.

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Synthesis Evaluation

• Individual synthesis efforts were ask to compute
  indices from their results prior to the workshop
  and make them available to the project for
  further evaluation.
• Input has been solicited from individual basin
  panels regarding metrics and indices for global
  reanalyses and the identification of CLIVAR
  reference data sets.
• The evaluation effort will be based on results
  available from the period 1950 to present,
  including those that cover the TOPEX/JASON-1 era.
  

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Global Science Questions

• 1) THE OCEANS IN THE PLANETARY HEAT BALANCE
• heat storage,
• heat transports and
• ocean/atmosphere feedbacks.
• 2) THE GLOBAL HYDROLOGICAL CYCLE
• water balance,
• rainfall variability
• salinity and convection.
• 3) SEA LEVEL
• sea level rise
• sea level variability.

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SST in boxes
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2nd Synthesis Evaluation

• Possible dates Sept. 24/25
• Think about reasons for existing differences in
  syntheses and try to pin them down a bit more.
• Start a discussion about error information
  required as input to the assimilation approaches
  and required to complement the estimated fields.
• Think about what CLIVAR needs and what we have.
  That might include also initialization of coupled
  models or even coupled model assimilation.
• We might want to address ice assimilation as
  well.
• Produce recommendations with regard to future
  synthesis resource planning and recommendations
  for CLIVAR data processing and management.
• Stimulation for WGOMD and IPCC to join in.

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Synthesis Evaluation-2

• Green Building, Room 915
• MIT
• September 24 - 25, 2007
• The meeting is intended to be a follow-up of the
  first synthesis evaluation meeting held at ECMWF.
  
• Goals of meeting include
• Review progress in ocean synthesis since last
  year.
• Review the computation of climate indices from
  ocean syntheses.
• Identify causes for inferred differences between
  syntheses.
• Discuss error covariances and their use in ocean
  state estimation.
• Identify synthesis requirements for support of
  CLIVAR.
• Among the outcome of the meeting will be a first
  statement about CLIVARs requirements on
  synthesis results as fare as it can be drawn from
  the existing synthesis evaluation results.

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Agenda

• Summary of results from previous meeting (D.
  Stammer)
• Progress since last meeting (T. Lee) each
  individual project 15 min.
• Discussion of discrepancies in synthesis results
  (T. Lee, K. Haines)
• Synthesis Application Global Sea Level Trends
• Status of coupled approaches (incl.
  initialization) (T. Rosatti, T. Awaji)
• Uncertainties in surface fluxes (D. Legler)
• Data errors/use of different datasets (R. Ponte)
• Discussion of error covariances and
  initialization (A. Weaver)
• Ocean reanlayses that span the 20th Century (J.
  Carton and B. Gise)
• Review of data requirements for assimilation (D.
  Stammer)
• Review of climate index computations and GSOP Web
  page (P. Hacker)
• Discussion of synthesis capabilities for serving
  CLIVAR needs (C. Wunsch, D. Stammer)

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GSOP Workshop on Ocean Velocity Measurements and
their Application

• Chairs Rick Lumpkin (AOML, Miami) and Brian
  King (NOC, Southampton)
• Venue and dates Scripps Institution, December
  5th, 6th, 7th (until 1545 if needed) 2007.
• The objective of the workshop is to establish
  CLIVAR's requirements for measurements of ocean
  velocity as a component of the suite of ocean
  observations needed for climate research. The
  format of the workshop will be refined by the
  convenors in consultation with the workshop
  attendees, and the GSOP co-chairs.
• The expected outcomes of the meeting are
• 1) review, document and characterise ocean
  velocity data presently available or likely to
  become available in the near future
• 2) review current dissemination and storage of
  ocean velocity data streams and identify
  enhancements to make their exploitation more
  effective
• 3) identify critical ocean velocity data streams
  that may constitute a global network and
• 4) develop the scientific justification and
  requirements that define the need for the
  inclusion of ocean velocity measurements in the
  suite of ocean observations used in climate
  research.
• A report from the meeting will be provided to the
  GSOP co-chairs. It is envisaged that this
  document could then be used to justify the
  inclusion of ocean velocity data as a component
  of a global ocean / climate observing system in
  CLIVAR and beyond. 

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GSOP-3

• Proposed venue Southampton (UK)
• Proposed dates 13-14 March 2008
• Panel members and some invited experts, with
  likely number to be around 20 people.
• Specific objectives and key agenda items Report
  to panel on outcomes and action items from (1)
  2nd CLIVAR/GODAE ocean synthesis meeting (2) 1st
  Hydrography advisory goup meeting (3) Ocean
  velocity workshop. Identify action items from
  these meetings for GSOP to address.
• Discussion the role of GSOP in proposed
  OceanObs09 conference.
• This meeting will be held close to the Argo
  Science Team meeting, which will be held in
  Exeter, UK, on 17-20 March. GSOP panel members
  who are also part of the AST will have their
  travel funded by the Argo Program. US CLIVAR has
  supported GSOP members from the US. Requested
  WCRP funding is US 7K.

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GSOP TOR

• 1. Develop, promote and seek to implement
  strategies for a synthesis of global ocean,
  atmosphere and coupled climate information
  through analysis and reanalysis efforts and
  through the use of other techniques where
  appropriate. Initial emphasis will be on global
  ocean synthesis efforts, building on previous
  experiences and developments.
• 2. Be responsible for the definition and
  fulfilment of CLIVAR's global needs for sustained
  observations (in collaboration with relevant WMO
  and IOC bodies, including GCOS, GTOS, GOOS, AOPC
  and OOPC, and JCOMM), and for the development of
  a strategy for their evolution/optimization based
  on new science and reanalysis insights, and
  fostering the use of resulting data sets in
  global synthesis efforts.
• 3. Promote activities to develop the surface flux
  data sets required by CLIVAR in liaison with the
  WGNE, global atmospheric reanalysis efforts and
  the WCRP Working Group on Surface Fluxes.
• 4. Provide an overview of and directions to
  CLIVAR data management and information activities
  in collaboration with other WCRP projects and in
  liaison with CLIVAR-relevant data centres and
  DACS and the ICPO.
• 5. Liaise and collaborate with CLIVAR Panels and
  Working Groups in identifying the requirements
  for and coordinating the development of an
  observing system for CLIVAR.

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• CLIVAR SSG-14 requested the ICPO scope need -
  carried out through GSOP who are supportive
• OthersSponsoring organizations (the International
  Ocean Carbon Coordination Project (IOCCP) and the
  SOLAS/IMBER Carbon Group - SIC) each approved the
  development of this advisory group in 2006, and
  earlier this year, the Observations Coordination
  Group of the IOC-WMO Joint Technical Commission
  on Oceanography and Marine Meteorology (JCOMM)
  and the GCOS-GOOS-WCRP Ocean Observations Panel
  for Climate (OOPC) strongly endorsed its
  development.