Implementation Plan for the Global Observing System for Climate in Support of the UNFCC, 2004
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2.1. Essential Climate Variables
The Second Adequacy Report established a list of the Essential Climate Variables (ECVs) (see Table 1) that are both currently feasible for global implementation and have a high impact on the requirements of the UNFCCC.
3.5. Integrated Climate Products
While observations of the climate variables are an essential pre-requisite, the users of the information generally require analyzed outputs and products. Thus developing analyzed products for all ECVs is vital. While the Parties are operating a number of analysis centres for some of the atmospheric variables, additional operational analyses are required. International coordination of these activities is highly desirable to take advantage of advances, avoid duplication, and promote efficiency, complementarity and cooperation rather than competition. It is also important to recognize that alternative analysis approaches are required to verify the accuracy of the various outputs for specific variables. At this point in time, there are few analysis centres that are integrating observations of a given variable using data from different networks. The integrated products should include estimates of the uncertainty inherent in the analysis.
Achieving the integrated analyses required for each ECV is a priority near-term objective. Actions on individual variables are noted below in Sections 4, 5, and 6. In accordance with the Second Adequacy Report, it is recommended that the IGOS-P continue to develop strategies for implementing these global products. GCOS in turn needs to extend the number of ECVs for which integrated products are being generated and improved by coordinating actions by national and regional centres and programmes, by the intergovernmental organizations, by the multiple agencies through the IGOS-P, and in the future, with GEOSS. Some ECVs will require active research programmes to develop the tools necessary to produce climate-quality integrated analyses (see Sections 3.8, 4.6, 5.5 and 6.4).
Real-time data assimilation and reanalysis is another method of generating integrated products and exploits the physical relationships among a number of the variables and thus uses many of the available types of observations. It is an increasingly powerful tool that has significant potential for providing a comprehensive picture of the climate system. Because an adequate observational record for reanalysis extends for only 40 years or so, the main focus and success of real-time dataassimilation and reanalysis to date has been on the relatively short-term variability of the atmosphere rather than on long-term climate trends of the essential climate variables. The latter places particular demands on the reanalysis systems and on the observational data that are ingested. Ocean data assimilation and reanalysis is just now developing and terrestrial activities are in their infancy, owing to a lack of modelling infrastructure, historical data and limited institutional engagement.
Although the quality of reanalyses is at present insufficient for a number of climate applications, there are good reasons to be optimistic. The opportunity exists to develop improved procedures for climate reanalyses and thereby reveal long-term trends. As part of an internationally-coordinated effort, there is a need for a small number of reanalysis centres with adequate staff and data processing, to prepare integrated climate products. The international reanalysis programme should give initial priority to: (a) extending current atmospheric reanalysis activities to meet requirements for monitoring climate variability and trends; (b) building on and extending ocean data-assimilation research activities such as the Global Ocean Data Assimilation Experiment (GODAE) to establish ocean reanalyses for the recent satellite era, and for longer if practicable; and (c) developing products relating to the composition and forcing of the climate system. The outputs of the reanalysis programme will have wide use and should be easily available to the user community. Although reanalysis can enable value to be derived from a wide range of comprehensive data sources, a climate-quality reanalysis is only possible when the data sources include a significant fraction of data adhering to the GCMPs. The identified GCOS networks in the atmosphere and the proposed networks drifting buoys and sub- surface floats in the ocean are critical in this respect. The availability of national holdings of historical data to the International Data Centres is an essential requirement for the effective conduct of reanalysis.
Establishing continuing capabilities for reanalysis for each domain, recognizing the early stage of development of assimilation in the Oceanic and the Terrestrial Domains, is essential. GCOS will work with the respective technical commissions and international research programmes to develop a coordinated set of analysis and reanalysis centres. In addition, the GCOS/GTOS Terrestrial Observation Panel for Climate (TOPC) and the GCOS/GOOS/WCRP Ocean Observations Panel for Climate (OOPC) will continue to encourage continuation of pilot projects and associated research on ocean and terrestrial data assimilation. Finally, the International Data Centres, e.g., the World Data Centres (WDCs), should continue to work with the responsible technical commissions and research programmes to ensure the provision of historical data sets including meta-data to internationally- mandated archives for inclusion in reanalysis programmes.
Action C11 (CF5)
Action: Prepare the data sets and meta-data, including historic data records, for climate
analyses and reanalyses.
Who: Parties with the International Data Centres (e.g., WDCs), working together with technical
commissions and the scientific community.
Time-Frame: Now and ongoing.
Performance Indicator: New or improved data sets available for analysis or reanalysis.
Cost Implications: Covered in domains. Sum of costs Category III.
Action C12 (CF3)
Action: Establish sustainable systems for the routine and regular analysis of the ECVs, as
appropriate and feasible, including measures of uncertainty.
Who: Parties sponsoring internationally-designated analysis centres with guidance from WCRP,
IGBP and IPCC, with oversight by GCOS.
Time-Frame: Now and ongoing, with most ECVs addressed by 2009.
Performance Indicator: Quality and range of analyses of the ECVs.
Cost Implications: Covered in domains. Sum of costs Category IV.
Action C13 (CF4)
Action: Establish a sustained capacity for global climate reanalysis and ensure coordination and
collaboration between reanalysis centres.
Who: National and international agencies, with coordination and oversight by GCOS and
Time-Frame: Established programmes across all domains by 2009, ongoing activity thereafter.
Performance Indicator: Reanalysis centres established and/or endowed with long-term and
coordinated programmes; cyclical flow of products of improving quality and widening range.
Cost Implications: Covered in domains. Sum of costs Category III.
- 09 Apr 2009