An integral component of the new mandate of the National Oceanic and Atmospheric Administration (NOAA) to “understand climate variability and change to enhance society’s ability to plan and respond” involves creating a scientific data stewardship (SDS) plan to generate, analyze, and archive long-term satellite climate data records (CDRs) for assessing the state of the environment. As defined by the National Research Council (NRC, 2004), a climate data record is a time series of measurements of sufficient length, consistency, and continuity to determine climate variability and change. That report further defined fundamental climate data records (FCDRs), which are calibrated and quality-controlled sensor data that have been improved over time, and thematic climate data records (TCDRs), which are geophysical variables derived from the FCDRs, such as sea surface temperature and cloud fraction. More explanation of the differences between FCDRs and TCDRs along with examples of specific CDRs are provided in the committee’s first report (NRC, 2004).
Not all time series of climate-related variables are designated as CDRs. Variables chosen for CDR development should address key questions about the climate system and lead to clear improvements in (1) scientific understanding of the climate system; (2) projections for future climate states; (3) regional, national and international climate assessments; and (4) the nation’s ability to respond to climate variations. The CDRs should be based on the best scientific research and measurement capability available, and they should represent a consensus within the scientific community regarding what is to be monitored and measured over time. It is critical that stewardship entails continuous overview and involvement by scientists to ensure that CDRs are properly generated and maintained.
NOAA’s new climate mandate is fundamentally different from its traditional weather forecasting mandate and raises a new set of challenges related to the stewardship of CDR data. To meet these challenges, NOAA asked the National Research Council (NRC) to convene a committee of experts to assist in designing a CDR program. The committee held several meetings, including an information gathering workshop attended by several dozen scientists. A questionnaire was also distributed to conference participants and to others via the Internet. Based on input from the scientific community and committee expertise, the NRC published Climate Data Records from Environmental Satellites (NRC, 2004) to provide NOAA with initial guidelines.* In particular, NRC (2004) identified 14 key elements for creating a CDR program (Box 1). As stated in that report, the committee believes that adherence to these elements would help NOAA to create CDRs that are based on the standards of the scientific community, while ensuring that they remain responsive to the needs of other users.
Underlying many of these elements of success is early attention to data stewardship, management, access and dissemination policies, and the actual practices implemented. Because a successful CDR program will ultimately require reprocessing, datasets and metadata should be preserved indefinitely in formats that promote easy access. The ultimate legacy of long-term CDR programs is the data left to the next generation, and the cost of data management and archiving must be considered an integral part of every CDR program.
This report is the second phase of the committee’s activities, written to provide specific input to NOAA on its February 18, 2005 draft “Scientific Data Stewardship (SDS) Implementation Plan.” The draft plan describes a new effort by NOAA “to create high-quality, operational long-term data sets of climate conditions—Climate Data Records—from satellite and supporting ground-based observations” (NOAA, 2005, p. 5). The new SDS program will take on the responsibility of processing, archiving, and distributing observations to users. These observations are intended for use in monitoring, diagnosing, understanding, predicting, modeling, and assessing climate variation and change.
CDR Organizational Elements
CDR Generation Elements
Sustaining CDR Elements
NOAA is to be commended for endorsing the CDR concept, embracing the importance of long-term CDR stewardship, and accepting the lead role in the generation and sustenance of critical climate records in coordination with agency, academic, and private sector partners. NOAA has taken the initiative in developing an implementation plan. Such a plan will be indispensable to the success of the forthcoming CDR program. The members of the NRC Committee on Climate Data Records from NOAA Operational Satellites are pleased to see NOAA’s interest in engaging the broader satellite and climate communities in their plan. Furthermore, NOAA’s positive response to panel recommendations regarding the organization, generation, management, and overarching stewardship of a CDR program is promising.
It is encouraging to see current and proposed NOAA budgetary support for an SDS program and for the Comprehensive Large Array-data Stewardship System (CLASS). Both are vital to the fulfillment of NOAA’s climate mission, and neither can succeed independently. However it is critical to maintain a distinction between the stewardship of scientific data and scientists having oversight of data stewardship. The former should be the responsibility of CLASS, while scientific vigilance should be within the province of SDS. A close and on-going
consultation is needed between those designing and building CLASS and the climate scientists who will use it.
Overall, the NRC committee finds Draft 3.1 of the SDS Implementation Plan (NOAA, 2005) to be sound and to include mechanisms for continued user involvement. The committee believes that the plan document should be revised in several ways to clarify its intent—for example, giving the discussion of implementing the program (currently found in Chapter 4 of the draft) more prominence by introducing it earlier in the draft and providing more specific details about implementation. The remainder of this report recommends ways to improve the NOAA (2005) SDS draft and enhance program implementation. As in the committee’s earlier report (NRC, 2004), comments are addressed within the framework outlined in Box 1—namely, organizational, generation, and sustaining elements of a successful CDR program.
Although the committee recommends that the plan’s authors revise the document, the committee believes that these revisions should not hinder implementation. Indeed, the plan embraces the committee’s overarching recommendation from its first report, as well as the six supporting recommendations (see Box 2), indicating a level of consensus among the committee members and the NOAA authors about the value of these recommendations. These steps are essential to effective implementation of a climate data records programs. While the draft plan demonstrates that NOAA has a general understanding of the issues associated with developing a CDR program, serious thought is still needed in the details of implementing the plan. The committee expects that as NOAA moves forward it will have to revise the plan on a regular basis to incorporate new understanding based on experience as well as to accommodate anticipated growth in the program. In short, NOAA should immediately begin implementing the scientific data stewardship program while revising it along the lines of the recommendations in this report.
OVERARCHING RECOMMENDATION: NOAA should embrace its new mandate to understand climate variability and change by asserting national leadership for satellite-based Climate Data Record generation, applying new approaches to generate and manage satellite Climate Data Records, developing new community relationships, and ensuring long-term consistency and continuity for a satellite Climate Data Record generation program.
Supporting Recommendation 1: NOAA should utilize an organizational structure where a high-level leadership council within NOAA receives advice from an advisory council that provides input to the process on behalf of the climate research community and other stakeholders. The advisory council should be supported by instrument and science teams responsible for overseeing the generation of Climate Data Records.
Supporting Recommendation 2: NOAA should base its satellite-based Climate Data Record generation program on lessons learned from previous attempts, which point out several unique characteristics of satellite Climate Data Records, including the need for continuing calibration, validation, and algorithm refinements, all leading to periodic reprocessing and reanalysis to improve error quantification and reduce uncertainties.
Supporting Recommendation 3: NOAA should define satellite Climate Data Record stewardship policies and procedures to ensure that data records and documentation are inexpensive and easily accessible for the current generation and permanently preserved for future generations.
Supporting Recommendation 4: NOAA should develop new community relationships by engaging a broader academic community, other government agencies, and the private sector in the development and continuing stewardship of satellite Climate Data Records.
Supporting Recommendation 5: NOAA should consider existing U.S. multi-agency organizations for implementation of the Climate Data Record program, rather than devising a new structure. The most appropriate organization is the Climate Change Science Program.
Supporting Recommendation 6: NOAA should pursue appropriate financial and human resources to sustain a multidecadal program focused on satellite Climate Data Records.