Conclusions and Recommendations
NOAA’s new vision is to “move into the 21st century scientifically and operationally, in the same interrelated manner as the environment that we observe and forecast, while recognizing the link between our global economy and our planet’s environment.” This vision includes a new mandate to understand climate variability and change to enhance society’s ability to plan and respond. Given the inherent complexity of climate, reliable and stable long-term observations are needed to describe and potentially predict climate. This naturally encompasses a global view and highlights the importance of using satellite data. However, great care must be taken to ensure that the climate data records (CDRs) based on satellite observations have the necessary reliability and consistency to distinguish between artificial changes related to the observing system and real changes in climate. Developing a successful satellite CDR generation program poses many challenges owing to the varied uses of climate data, the complexities of data generation and storage, and the difficulties in sustaining the program indefinitely. This chapter highlights the key findings of the committee and addresses the important recommendations that will help to ensure that NOAA designs a plan to guide satellite CDR generation from existing and new satellites for understanding, monitoring, and predicting climate variations and changes. We present one overarching recommendation and six supporting recommendations.
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.
NOAA already is well established as a national leader in weather services, and NOAA also provides leadership for weather-based satellite data. NOAA’s climate mandate is a new function, and NOAA will need to embrace and be proactive in providing leadership for climate data in order to fulfill its mandate. A successful CDR generation program requires a long-term commitment and efforts above and beyond NOAA’s traditional role in weather forecasting. The task and the structures being proposed for NOAA in this report are considerably more complex, costly, and demanding than those currently in place. Unless there is the highest level of commitment within the agency to institute and fund these changes, there is considerable doubt in the science community that the CDR agenda as described in the report will succeed.
The committee’s review of some previous efforts reveals a number of key lessons learned relating to the involvement of user communities in all program aspects and adhering to several guidelines for creating, storing, and reprocessing fundamental climate data records (FCDRs) and thematic climate data records (TCDRs).1 Particular care is needed to store all data with thorough metadata and in easily accessible formats. NOAA should not feel obligated to be solely responsible for generating all the nation’s CDRs; many other agencies and communities have similar interests and expertise, and by enhancing and expanding community involvement in the program NOAA can help to ensure community acceptance and creation of the best possible CDRs.
APPLYING NEW APPROACHES TO GENERATE AND MANAGE SATELLITE CDRS
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.
See Figure 1-2 for the distinction between FCDRs and TCDRs.
NOAA would benefit greatly from utilizing an organizational framework responsive to advice and feedback from user communities, and where there are mechanisms for redirecting the program based on advice and feedback. In particular, NOAA can help to ensure success if it involves scientists with a vested interest in CDRs, finds committed people to generate the CDRs, develops technical and science support for broad involvement, and creates teams that are reviewed and renewed regularly.
An advisory council should establish criteria for selecting climate variables to become satellite-derived TCDRs and recommend which variables should be developed into TCDRs based on proposals from thematic science teams. Since NOAA cannot create all possible TCDRs, mechanisms must be in place to select an appropriate number to generate. Based on input from user communities, an advisory council of internationally recognized experts can recommend to NOAA which TCDRs should be created and subsequently whether these TCDRs are accepted and utilized by the community.
The generation of FCDRs should be carried out by a team of engineers and scientists, with representatives from the thematic science teams to ensure feedback from the generation of TCDRs. The ultimate legacy of the CDR program is the data passed on to the next generation. To ensure that the FCDRs are generated with the highest possible accuracy and stability, the FCDR teams should monitor satellite characteristics and they should document their work extensively so that future generations can easily assess and understand what they have done.
TCDR Science Teams formed within broad interdisciplinary areas should prescribe algorithms for TCDR development and oversee TCDR generation. Most users will utilize TCDRs, not FCDRs, and the success of NOAA’s program is dependent on creating reliable and stable TCDRs. The TCDR teams should be led by recognized scientists who are actively engaged in using the data. These teams should include research scientists funded by or employed by NOAA and scientists from other agencies, academia, and private industry who use the data, and they should be competitively selected, with limited (but renewable) terms.
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 calibra-
tion, validation, and algorithm refinements, all leading to periodic reprocessing and reanalysis to improve error quantification and reduce uncertainties.
NOAA should make radiance calibration, calibration monitoring, and satellite-to-satellite cross-calibration a part of the operational satellite system. Changes in satellite characteristics, such as orbital drift and sensor degradation, compromise the ability to create high-quality, consistent CDRs over time. Procedures must be in place to monitor the observing system for irregularities that could corrupt the long-term value of the FCDRs. A suitable period of overlap between new and old satellite systems is also vital to determine inter-satellite biases and maintain the consistency of time-series observations. Since most of NOAA’s operational satellites were created as weather rather than climate platforms, this is notably relevant for NOAA to address.
An ongoing program of validation should be carried out to determine the uncertainty associated with TCDRs. The process of validating a TCDR derived from satellite measurements is not simply a one-time activity carried out in a limited number of locations. It is the process of establishing rigorously derived uncertainties for the TCDR using independent correlative measurements conducted throughout the time period of record and over global scales, which in turn determines whether a true climate trend can be detected.
NOAA should establish a two-track CDR generation program, including an upgradeable baseline CDR track and a second (mostly extramural) funded research program to validate, analyze, assess, and reduce uncertainties in future base versions. The two-track approach helps foster a culture where scientists and users know that future improvements will be available. The FCDRs will need to be reprocessed as new information is acquired or better calibrations are made, but these records will eventually become stable. The TCDRs will continue to change indefinitely as new or improved algorithms are developed and improved applications are made of the FCDRs.
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.
The data management system should provide free and open access to data, facilitate the reprocessing of CDRs, and allow for new satellite CDRs to be created. There is a need for a clear policy from the beginning to ensure continuity in the data record as well as full and open access to data and metadata, including the ancillary data required to reprocess the CDRs, project and dataset documentation, the science production software, and easy error-reporting procedures. Preserving the documentation with the data is important for future reprocessing of archived data. A variety of users will access data, and NOAA can ensure a more robust program if the data are available in formats appropriate for a variety of uses, including geospatial and socio-economic applications.
NOAA should ensure a data management infrastructure that can accommodate specific user requests. In view of the large satellite data volumes that a CDR program will create, the NOAA infrastructure needs to provide tools enabling the user to do spatial and temporal searches and arbitrary subsetting. These levels of service should be determined and implemented in the design of the system infrastructure.
NOAA should establish a process for scientifically assessing the long-term potential of data and data products. Lifecycle data management from initial planning through development and implementation is needed for a successful program, and this should involve cooperation among researchers, data and archive managers, data collectors, and primary users. Given the limited resources that programs face, scientific assessments of the data can help NOAA to organize its archive so that data dissemination is efficient in terms of personnel and financial resources.
DEVELOPING NEW COMMUNITY RELATIONSHIPS
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.
NOAA should annually convene an “open science meeting” where users share their findings (i.e., give science talks) and discuss limitations and recommendations for improving the TCDRs in a particular theme area. Regular opportunities for open dialog between those creating CDRs and those using them will improve the quality of the data and foster support for
continuing the CDR generation program. These meetings could be held in conjunction with conferences held by other organizations, such as the American Meteorological Society or the American Geophysical Union, with benefits being cost savings and broader attendance.
NOAA should include other agencies and user communities in development, analysis, and reprocessing of CDRs. A high level of commitment within NOAA and a number of changes at multiple levels within the agency will be needed to institute and fund the various components of CDR stewardship, but it will still be essential to aggressively seek out partnerships. The expertise for creating satellite CDRs lies within the broad academic, government, and private sectors, and through partnerships with these entities NOAA can ensure a more successful CDR generation program. By including the other sectors in the CDR generation, analysis, and reprocessing program, NOAA can also engender community acceptance of CDRs. The committee notes that NOAA may also need to develop new ways of working with partner organizations. Well-defined procedures for interagency communication and collaboration are essential for long-term stewardship and the success of the CDR program.
NOAA should solicit a commitment from other agencies (e.g., NASA, NSF) and utilize many line offices to support research that utilizes the TCDRs. A commitment to support research that utilizes the TCDRs will help to ensure the program’s success, but this need not be the sole responsibility of NOAA.
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 (CCSP).
NOAA need not implement an entirely new management structure for generating CDRs. The goals and management structure of the developing Climate Change Science Program are similar to NOAA’s climate goals, and NOAA could assert leadership by volunteering to be the lead or executive agent for the observations and data management portion pertaining to satellite CDRs. The CCSP structure already has built-in interagency interactions that NOAA could leverage, and by taking the lead for satellite CDRs, NOAA could advance its new climate mandate.
ENSURING LONG-TERM STABILITY FOR A SATELLITE CDR GENERATION PROGRAM
Supporting Recommendation 6: NOAA should pursue appropriate financial and human resources to sustain a multidecadal program focused on satellite climate data records.
With a coordinated CDR effort under the CCSP, NOAA could provide the nation with the needed leadership to develop CDRs. Even if NOAA leverages funds and personnel from other agencies, academia, and private industry, the committee believes that NOAA will have to be aggressive in developing avenues for additional funds to provide the needed capital to successfully generate, analyze, reprocess, store, and disseminate CDRs for decades, taking inflationary increases into account. Developing a satellite CDR program is fundamentally important to the nation, and it is imperative that the effort not be inhibited by a lack of human or financial resources.