World Meteorological Organization

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By D. PARKER1, E. KENT2, S. WOODRUFF3, D. DEHENAUW4,D.E. HARRISON5, T. MANABE6, M. MIETUS7, V. SWAIL8, S. WORLEY9

Reprinted from WMO Bulletin 53 (2)April 2004

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BackgroundThe Second Joint WMO/IOC Technical Commissionfor Oceanography and Marine Meteorology (JCOMM)Workshop on Advances in Marine Climatology (CLI-MAR-II) was held in Brussels, Belgium, on 17-22November 2003 with more than 80 people from 20WMO Member countries attending. CLIMAR-II wasorganized jointly by JCOMM and the Royal Meteoro-logical Institute of Belgium, and sponsored by theBelgian Federal Science Policy Office, EnvironmentCanada, the Japan Meteorological Agency and the USNational Oceanic and Atmospheric Administration.

Proceedings

CLIMAR-II was divided into three main sessions oncross-cutting issues; sea-level pressure (SLP), windand waves; and marine temperatures and sea ice.Estimation of uncertainty was a common theme inall the sessions. Many of the presentations werebased on the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) (initially named I-COADS but now renamed as ICOADS to ease citationand Web paging). ICOADS incorporates the MetOffice’s Marine Data Bank and millions of newly digi-tized logbook records, with careful elimination ofduplicates (Diaz et al., 2002).

Comparison with the recommendations of theWorkshop on Advances in the Use of HistoricalMarine Climate Data (Boulder, USA, January/Febru-ary 2002) (Diaz et al., 2002) revealed that goodprogress had been made in many areas: data cover-

age; understanding and reducing biases; specifica-tion of uncertainties; quality-control (QC) tech-niques; availability of additional land-station sea-level pressure (SLP) data; and development oftechniques for reanalysis of atmospheric circulationin the pre-radiosonde era.

Other areas where some progress had beenachieved were: the approval by the WMO ExecutiveCouncil of a format for metadata from Ocean DataAcquisition Systems (ODAS) including buoys; analy-sis of diurnal cycles in sea-surface temperatures(SST) using geostationary satellite data; availabilityof satellite-based temperatures for inland seas andlarge lakes; research to improve the specification ofSST in marginal ice zones; assembly of the first ver-sion of a blended sea-ice dataset for the Arctic for1950-1998 by the JCOMM Expert Team on Sea Ice;improvement of cloud-clearing techniques for satel-lite-based SST; and assessment of biases in theMaury SLP data.

There had also been a substantial internationaleffort to prepare recommendations for enhance-ments to GCOS (GCOS, 2003).

Much, however, remains to be done: millions ofmarine observations remain to be located and digi-

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By D. PARKER1, E. KENT2, S. WOODRUFF3, D. DEHENAUW4,D.E. HARRISON5, T. MANABE6, M. MIETUS7, V. SWAIL8, S. WORLEY9

1 Met Office, United Kingdom2 Southampton Oceanography Centre, United Kingdom3 National Oceanic and Atmospheric Administration

(NOAA) Climate Diagnostics Center, USA4 Royal Meteorological Institute of Belgium 5 NOAA Pacific Marine Environmental Laboratory, USA6 WMO Secretariat7 Institute of Meteorology and Water Management, Poland 8 Environment Canada9 National Center for Atmospheric Research, USA

Figure 1 — Abstract log of the US Frigate Constitution, 1854-1855 (NavalObservatory Volume No. 345; Deutscher Wetterdienst Registration No. 8148(reprinted from Braun, 2000))

tized from logbooks (e.g. Figure 1), and millions thatare already digitized remain to be blended intoICOADS; the biases in marine temperatures around1939-1945 are still poorly understood. Daytimemarine air temperature (MAT) data need to be madeuseable (application of the GCOS Climate MonitoringPrinciples (Appendix 2 of GCOS, 2003)); assessmentsof uncertainties and assessment techniques need tobe improved; target accuracies need to be identified;large areas at and below the ocean surface remainunobserved. All these recommendations are applica-tions of the GCOS Climate Monitoring Principles(Appendix 2 of GCOS, 2003).

Certain Boulder recommendations, such as cre-ation of sub-monthly analyses of SST and sea ice, andadjustment of historical wind-speed data, are still atan early stage. CLIMAR-II supported the need forsub-monthly (pentad) analyses. Pentad SST analysesbased on satellite data (e.g. Reynolds et al., 2002) arevaluable but require in situ data for validation andoften for calibration also. Adjustment of historicalwind speeds is particularly difficult without meta-data. Some useful work has been done for the post-World War II period (e.g. Ward and Hoskins, 1996),which showed that the problems in the raw data areindeed serious, but this needs extending throughoutthe ICOADS period. QC techniques for all parametersneed to be fully and consistently documented; if pos-sible, QC methods used throughout ICOADS shouldbe homogeneous.

There were seen to be shortcomings in theaccess to ICOADS data. There are many, overlappingsources of data and products, and the problem ofoptimising data provision is complex. Many usersare working with outdated versions of COADS. Oftendata are available, but it is difficult for the uniniti-ated to discover what is there. There should be aWeb-based "route map" to the best available datawhich should be widely advertised to all the varioususer communities.

Recommendations by CLIMAR-IIVarious recommendations were made in the areas ofclimate monitoring, metadata, homogenization anddata availability. Ideally, all the recommendations(except that for holding CLIMAR-III) should beimplemented within two years. The consolidatedBoulder and CLIMAR-II recommendations are avail-able at http://www.cdc.noaa.gov/coads/climar2/recs.html.The need to improve GCOS, and to adhere to theGCOS Climate Monitoring Principles is implicit, bear-ing in mind that any distinction between "opera-tional" and "climate" observations is artificial. Therecommendations should be implemented in collab-oration with the various GCOS Panels and/or JCOMM.

Conclusions

Presentations made at CLIMAR-II will be incorpo-rated into a JCOMM Technical Report (JCOMM, 2004)and a selection of papers will be published in a spe-cial issue of the International Journal of Climatol-ogy, which will form an update of the Dynamic Partof the WMO Guide to the Applications of Marine Cli-matology (WMO-No. 781). CLIMAR-II will thus pro-vide guidance and technical support to NationalMeteorological Services in their acquisition, pro-cessing, analysis and application of marine meteoro-logical data.

Acknowledgements

We are grateful to the Royal Meteorological Institute of Belgiumfor hosting this important event. We thank Chris Folland andDick Reynolds for useful comments on this paper.

References

BRAUN, D.S., 2000: Scientific vision, a passion for observation, andthe impetus for change: Germany loans Maury logs to theNational Climatic Data Center. Earth System Monitor, 11, No.1, 4-7.

DIAZ, H., C. FOLLAND, T. MANABE, D. PARKER, R. REYNOLDS and S.

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Figure 2 (from left to right) — US steam frigate Mississippi, in the Gulf of Mexico, March 1847 (Library of Congress, Prints & Photographs Division [reproduction number LC-USZC2-3129] (originally published by N. Currier, New York, 1848)); Florida peninsula, January 1985 (NASA Space Shuttle Earth Observations Photography database [photoSTS51C-44-0026]); Tropical Ocean Atmosphere (TAO) buoy and anemometers on NOAA ship Ka’Imimoana (Photo by Jason Poe, courtesy of TAO Project Office)

WOODRUFF, 2002: Workshop on Advances in the Use ofHistorical Marine Climate Data, WMO Bulletin 51 (4), 377-380.

GCOS (WMO/IOC/UNEP/ICSU), 2003: The Second Report onthe Adequacy of the Global Observing Systems for Climate inSupport of the UNFCCC, GCOS-82, WMO/TD No. 1143.[Available from:

http://www.wmo.int/web/gcos/gcoshome.html.]JCOMM, 2004: Proceedings of CLIMAR-II. JCOMM

Technical Report No.22. WMO/TD No. 1199, on CD-ROM.

REYNOLDS, R.W., N.A. RAYNER, T.M. SMITH, D.C. STOKES andW. WANG, 2002: An Improved In Situ and Satellite SSTAnalysis for Climate. J. Climate, 15, 1609-1625.

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