to be covered. In the past decade, space weather needs have been served by improved observations from both operational and science missions, such as GOES, STEREO, and ACE. At the same time, there are deficiencies, for example, the likely absence of energetic-particle sensors on future NOAA low-altitude polar-orbiting satellites and uncertainty regarding their presence on future Air Force defense weather satellites.
Recently, there has been admirable progress as well as interagency cooperation among NASA, the U.S. Air Force, and NOAA to develop a long-sought and much-needed replacement for the aging ACE solar wind satellite, which was launched into a halo orbit around the L1 libration point in 1997. However, it now appears that the replacement spacecraft, DSCOVR, will not carry the coronagraph that is needed to replace observations from the SOHO spacecraft, which was launched in 1995. Moreover, instruments on DSCOVR, like those currently on ACE, have significant limitations in monitoring the highest-velocity events. IMAP, described above, provides an opportunity to apply to a next generation of solar wind instruments what has been learned over the past two solar cycles about solar wind variability.
In summary, the survey committee found that NOAA, DOD, and other agencies play an important role in maintaining and expanding the observational foundation of accurate and timely data used for space weather operations and space climatology. The survey committee also concluded that it is important that NASA continue to make science mission data available in cases in which those data contribute to timely space weather operations.
The survey committee recommends that NASA, NOAA, and the Department of Defense should work in partnership to plan for continuity of solar and solar wind observations beyond the lifetimes of ACE, SOHO, and STEREO. In particular,
• [A2.1] Solar wind measurements from L1 should be continued, because they are essential for space weather operations and research. The DSCOVR L1 monitor and IMAP STP mission are recommended for the near term, but plans should be made to ensure that measurements from L1 continue uninterrupted into the future.
• [A2.2] Space-based coronagraph and solar magnetic field measurements should likewise be continued.
• [A2.3] The space weather community should evaluate new observations, platforms, and locations that have the potential to provide improved space weather services. In addition, the utility of employing newly emerging information dissemination systems for space weather alerts should be assessed.
Research, the foundation for future improvements in space weather services, is necessary for progress and improvement in models that are just beginning to reach a level of maturity such that they can benefit space weather customers. But just as the first Sun-to-Earth model (WSA-Enlil) is being implemented at the National Centers for Environmental Prediction (Figure 4.11), space weather specialists are witnessing a major decline in support for model improvement and new model development. Continued support is critical to developing models that are useful for operational forecasts, focused primarily on addressing operational needs and prepared with the goal of making the transition from the research environment to operational service. Further, model development aimed at improving operational forecasts requires a dedicated effort focused on validation and verification. Finally, the pursuit of models that are meant to be more than just science tools is most effective when the end purpose is usefulness in operations. This in turn requires a close working relationship between the end users of space weather forecasts and the research community.