For research missions as for operational systems, observational requirements and considerations of data accessibility drive sensor and ground systems to a particular implementation that emphasizes innovation, data quality, and long-term accessibility. Rather than fly copies of specific sensors, the science research community generally prefers to fly new technology, and its missions are usually designed and implemented with strong scientific oversight. Sensor calibration and data product validation are critical elements of each mission. Ground systems focus on providing long-term access to low-level data to support reprocessing. Although there are cost constraints for research missions, these constraints are not applied to the system as a whole. Compelling new missions can be developed and funded somewhat independently of other elements of the NASA/ESE budget.
Although the operational and the research approaches can appear to conflict, there are features of both that are essential for climate research and monitoring. However, the operational agencies are necessarily wary of assuming responsibility for new requirements that may be open ended in an environment that is cost constrained. The research agencies are similarly concerned about requirements for long-term, operational-style measuring systems that might inhibit their ability to pursue new technologies and new scientific directions. Despite their need for long-term commitments to measure many critical variables, they wonder about relying on operational programs that might decrease the level of scientific oversight as well as opportunities for innovation.
Long-term, consistent time series are essential for the study of many critical climate processes, which vary over inherently long time scales. That said, many of the variables of interest for climate research have analogs in observing systems for short-term forecasting, although the performance requirements may differ significantly. For example, one of the fundamental attributes of operational observing systems—long-term commitment to data availability—is especially appealing to the climate research community. However, climate research also requires the ability to insert new observing capabilities to ensure that data remain at the state of the art as well as to respond to new science opportunities. Thus, the fundamental challenge is not the transitioning of research capabilities into the operational systems but rather the integration of the two capabilities in a rational manner. Both climate research and climate monitoring require a long-term commitment to consistent data sets and short-term flexibility to pursue new science and technology directions.
The integration of research and operational capabilities for climate research will require continuing cooperation between NASA and NOAA. Eventually, a single federal agency may be responsible for the overall climate observing strategy, but for the foreseeable future, the committee expects that the expertise from multiple agencies will be required. Its recommendations, therefore, are directed to NASA, NOAA, and the IPO.
The following are the key implementation issues:
Long-term comparability of data sets such that sensor performance and other technical performance issues are not mistaken for natural variability in Earth’s system (the committee prefers the term “comparability” rather than “consistency” because, in its view, the long-term objective is to develop data records that can be compared and the basis quantified—it is difficult to develop consistent data sets even with identical sensors);
Data product validation, including quantitative assessments of the temporal and spatial accuracy of the data;
Data continuity and strategies to launch replacement sensors to maintain the quality of the long-term data record;
Long-term archiving of data sets and capabilities for reprocessing and analysis;
Accessibility and availability of data, including pricing; and
Planning for technology insertion.