GCOS SST WG plans

1
GCOS SST WG plans

• Nick Rayner
• OOPC-12, 2nd May 2007

2
Executive Committee

• Tom Smith, NOAA (Co-chair)
• Nick Rayner, Met Office (Co-chair)
• Ken Casey, NOAA
• Alexey Kaplan, LDEO
• Liz Kent, NOCS
• Dick Reynolds, NOAA
• Ed Harrison, PMEL
• Craig Donlon, Met Office

3
Outline Terms of Reference

• To record and evaluate the differences among
  historical and near real time SST and SST/SI
  analyses
• To identify the sources of differences in the
  analyses
• On the basis of comparison of those differences
  with the expected climate signals in the SST
  patterns, to recommend actions needed to ensure
  the quality and consistency of the SST and SST/SI
  analyses
• To establish criteria to be satisfied by SST and
  SST/SI analyses to ensure the quality and
  consistency required by the Global Climate
  Observing System (GCOS)
• Liaise with all appropriate bodies
• To report annually to AOPC and OOPC on progress
  and recommendations

4
Outline plan

• Agreed set of diagnostics
• Initial set of analyses and input data
• Host website
• Data formats and inter-comparison tools
• Communication plan
• Turning the differences and similarities we
  discover into useful information for users

5
Agreed set of diagnostics

• Initial phase
• Time series of global and hemispheric anomalies
• Time-latitude sections of anomalies
• Fields of standard deviation, linear trend and
  lag1 correlation
• Follow on phase
• Maps of RMS differences between fields
• Time averaged difference maps
• Time series for selected regions and a small
  selection of GHRSST diagnostic data set sites
• Spatial autocorrelations.

6
Initial set of analyses

• Kaplan et al
• HadISST1
• NOCS SST analysis
• ERSST
• AVHRR Pathfinder
• OIv2
• Daily OI SST
• OSTIA

Plus input data, including ICOADS and HadSST2
7
Host website

• GHRSST-PP Reanalysis Long Term Stewardship and
  Reanalysis Facility http//ghrsst.nodc.noaa.gov/

8
Data formats and inter-comparison tools

• NetCDF-3 allows use of pre-existing data
  comparison tools, such as Ferret
• Compatible with GHRSST-PP fields
• Matlab and ASCII formats will also be maintained

9
Communication plan

• Draft and agree a document based on this
  presentation and feedback June 2007
• Create an email contact list of other
  international SST analysis colleagues
• Send document with invitation to participate end
  of August 2007
• Once we have initial results, widen the net and
  publicise to other users at appropriate meeting
• Explore possibility of a short paper or report.

10
Creating useful information for users

• Spread of different analyses gives initial
  indication of structural uncertainty
• Later propose to
• Explore differences in input data and QC
  techniques
• Apply different analysis techniques to the same
  data
• Need to carry out a user requirements exercise to
  find out what our users are trying to do and so
  what they need from us.

11
Liaison with appropriate bodies

• GHRSST-PP
• WCRP WGNE/WGSF SURFA project on common SST issues

12
Meeting of the SST/SI WG

• Currently discussing dates for meeting of the
  whole WG to discuss progress and points of common
  interest
• Fall AGU?