In this chapter the survey committee discusses its recommendations to the National Science Foundation (NSF) in the context of the committee’s recommended program in solar and space physics. Where appropriate, the chapter also addresses connections to the 2010 astronomy and astrophysics decadal survey, New Worlds, New Horizons in Astronomy and Astrophysics,1 which also made recommendations concerning NSF ground-based solar physics facilities and programs. Cost implications are considered, but because the recommendations to NSF are not fit to a specific budget, the committee does not prioritize its recommendations.
The committee’s baseline priority for NSF is to support existing ground-based facilities and to complete programs in advanced stages of implementation. These programs are described in Chapter 1 and illustrated in Figure 1.2 (the Heliophysics Systems Observatory). The global nature of solar and space physics is such that it requires a synergistic complement of space- and ground-based observational approaches, which both support and are supported by theory and modeling. Ground-based observations are also increasingly used in near-real-time data-driven models of the heliosphere and space weather. Synoptic and long-term measurements from ground-based instruments are essential for capturing the complex dynamics of geospace and observing long-term trends. Ongoing ground-based observations of the Sun likewise facilitate studies of long-term variations, as well as revealing solar features with the finest spatial resolution and presenting unique views of solar eruptions.
Maintaining ground-based observatories also requires that NSF maintain and develop, as necessary, systems for accessing, archiving, and mining synoptic and long-term data sets (see Appendix B and Box 4.1). Furthermore, in DRIVE “Integrate,” the committee describes the importance of expanding and formalizing the ground-based program’s contribution to the success of NASA Explorer- and strategic-class science so
1 National Research Council, New Worlds, New Horizons in Astronomy and Astrophysics, The National Academies Press, Washington, D.C., 2010.
that increasingly important synergies between ground- and space-based observations can be fully realized (see below, e.g., the subsection “A Heterogeneous Ionospheric Facility Network”).
When it begins operation in 2018, the 4-meter ATST will be, by far, the largest optical solar telescope in the world. Its ability to reach down to the fundamental photospheric density scale-length as a magnetometer, and to remotely sense coronal magnetic fields where they have never been measured, is revolutionary. However, despite facility closures by the National Solar Observatory (NSO), a significant increase in NSO base funding will be required to fully exploit the capabilities of the ATST. The NSO long-range plan estimates that ATST operations and data services will require at least $18 million per year, plus $4 million per year for NSO synoptic programs. Research grants and advanced instrumentation development would require additional funds.
The committee’s DRIVE initiative “Realize” recommendations emphasize the importance of NSF providing the ATST with base funding sufficient for operation, data analysis and distribution, and development of advanced instrumentation for the ATST in order to realize the scientific benefits of this major national investment. This emphasis agrees with the 2010 astronomy and astrophysics decadal survey recommendation regarding the need to develop a funding model for ATST operation, instrumentation, and scientific research.
Important research is often accomplished through midscale research projects that are larger in scope than typical single principal investigator (PI)-led projects (MRIs) and smaller than facilities (MREFCs). The Advanced Modular Incoherent Scatter Radar (AMISR) is an example of a midscale project widely seen as having transformed research in the ground-based AIM community. Although different NSF directorates have programs to support unsolicited midscale projects at different levels, these programs may be overly prescriptive and uneven in their availability, and practical gaps in proposal opportunities and funding levels may be limiting the effectiveness of midscale research across NSF. It is unclear, for instance, how projects like the highly successful AMISR would be initiated and accomplished in the future. Mechanisms for the continued funding of management and operations at existing midscale facilities are also not entirely clear.
The NSF Committee on Programs and Plans formed a task force to study how effectively it supports midscale projects, how flexible the funding is, how uniformly it is administered across NSF, and how well such projects serve the interests of education and public outreach. The resulting report affirmed the importance of strongly supporting midscale instrumentation but did not recommend any new or expanded NSF-wide programs. Nevertheless, as described in Chapter 4 in the “Diversify” recommendations of DRIVE, the committee strongly endorses the creation of such a competitively selected midscale project line for solar and space physics. This approach is also consistent with the 2010 astronomy and astrophysics decadal survey, which recommended a midscale line as its second priority in large ground-based projects.2
2 In that report, the recommendation for NSF to establish a “Mid-Scale Innovations Program” was accompanied by the following: New discoveries and technical advances enable small- to medium-scale experiments and facilities that advance forefront science. A large number of compelling proposed research activities submitted to this survey were highly recommended by the Program Prioritization Panels, with costs ranging between the limits of NSF’s Major Research Instrumentation and MREFC programs, $4 million to $135 million. The committee recommends a new competed program to significantly augment the current levels of NSF support for midscale programs. An annual funding level of $40 million per year is recommended—just over double the amount currently spent on projects in this size category through a less formal programmatic structure. The principal rationale
This survey committee’s white-paper process and the subsequent disciplinary panel studies brought forward a number of important heliophysics projects that would require a new midscale funding line. The examples below illustrate the kind of science that the line could enable. The survey committee chose not to explicitly rank these projects but notes that the first two have well-developed science and implementation plans and have already been vetted by NSF. These projects are seen as being central to the integrated science program outlined in this report and as highly synergistic with the ATST as well as NASA flight programs.
The Frequency-Agile Solar Radiotelescope (FASR)
Designed specifically for observing the Sun, FASR will produce high-quality images of radio emissions in the 50-MHz to 21-GHz band with fine spatial, spectral, and time resolution. The radio emissions of interest convey unique, otherwise inaccessible information about the solar atmosphere and the acceleration of energetic particles. Discoveries in the areas of quiet sun physics, the evolution of coronal magnetic fields, solar flares, and space weather drivers are anticipated with the undertaking of this project. FASR was ranked highly by both the 2003 solar and space physics decadal survey3 and by the 2010 astronomy and astrophysics decadal survey.4
The Coronal Solar Magnetism Observatory (COSMO)
COSMO will make continuous synoptic measurements of the corona and chromosphere, investigating solar eruptive events that are central to space weather and other solar-cycle-timescale and long-term coronal phenomena. Observations will show how the coronal magnetic field behaves across the sunspot cycle and how the polarity reversal of the global field affects the heliosphere. COSMO data will provide information about interactions between magnetically closed and open regions that determine the changing structure of the heliospheric magnetic field. The large field of view and continuous observations of COSMO will complement high-resolution, but small field-of-view, coronal magnetic field observations that may be made by the ATST.
In addition, the committee identified four other projects that would be suitable for the midscale line. These projects are not yet well developed but represent the kind of creative approaches that will be necessary for filling the gaps in observational capabilities and for moving the survey’s integrated science plan forward. They are the following.
for the committee’s ranking of the Mid-Scale Innovations Program is the many highly promising projects for achieving diverse and timely science.
See National Research Council, New Worlds, New Horizons in Astronomy and Astrophysics, 2010, p. 23.
3 National Research Council, The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and Space Physics, The National Academies Press, Washington, D.C., 2003; and National Research Council, The Sun to the Earth—and Beyond: Panel Reports, The National Academies Press, Washington, D.C., 2003.
4 National Research Council, New Worlds, New Horizons, 2010.
An All-Atmosphere Lidar Observatory
The most significant discoveries in the AIM discipline over the past decade involve increased appreciation of the influence of neutral atmospheric waves and instabilities on ionospheric structure and dynamics. An impediment to further research is the lack of direct, ground-based observations of the dynamics and thermodynamics of the mesosphere and, crucially, the thermosphere. Recent technical developments in the areas of high-power Rayleigh lidar and new resonance lidars now offer the possibility of wind and temperature measurements from the ground well into the thermosphere for the first time. A lidar observatory capable of observing gravity waves and tides and associated phenomenology in the mesosphere and lower thermosphere would accelerate discovery across the AIM discipline.
A Heterogeneous Ionospheric Facility Network
Processes central to AIM science are multiscale in nature, with global features that extend from the equator to the poles together with local features such as embedded small-scale irregularities that intermittently affect communications. Examples include traveling ionospheric disturbances, regions of storm-enhanced density, and the ionospheric response to sudden stratospheric warming events. Capturing these phenomena will require the deployment of an autonomous network of heterogeneous instruments, using optical and radio remote sensing techniques to measure neutral winds and temperatures, plasma densities, and plasma irregularities. Such a network would become a valuable facility in its own right, comparable to an EarthScope USArray5 for heliophysics, and would also be the ground-based counterpart to space-based investigations, complementing everything from CubeSat projects to NASA strategic missions.
A Southern-Hemisphere Incoherent Scatter Radar
The AMISR phased-array incoherent scatter radar has proven to be a most incisive instrument for measuring the state properties of the ionosphere with panoramic coverage and high precision. Unknown, however, is the degree of inter-hemispheric conjugacy that can be assumed. The next logical step is to deploy an AMISR face in the Southern Hemisphere, expanding the latitudinal coverage of the heterogeneous network further. A deployment in the Antarctic region in particular would allow for the first ground-based assessment of conjugacy of geomagnetic storms.
Next-Generation Ground-Based Instrumentation
There is a need to support continuing instrumentation and technology development for ground-based solar physics in both the national facilities and the universities. Support for advanced instrumentation and seeing-compensation techniques for the ATST and other solar telescopes is necessary to keep ground-based solar physics at the cutting edge. At the same time it is necessary to ensure that adequate support is available to nurture young scientists and engineers in the field of solar instrumentation. That implies a need for adequate funding and good career opportunities, including the opportunity to work on exciting new instrumentation projects.
The efforts by NSF’s Atmospheric and Geospace Sciences Division (AGS) to support student CubeSats have engendered an enormous amount of interest from universities and partner institutions. As of October 2011, eight CubeSat projects were underway. Launches have been scheduled (between 2011-2013) for all but two of the projects. NASA’s ELaNA program is instrumental in obtaining launch opportunities and serves as a model for other small-satellite projects discussed by the survey.
All of the projects have been deemed by peer review to have well-defined, important science objectives and to provide unique data sets. All involve entirely new flight hardware and carry the promise of precedent-setting measurements. The limitations imposed by the small platforms demand a high degree of technical innovation in terms of power, control, storage, and downlink. CubeSats provide a unique platform for technological innovation whereby technical readiness can be developed to levels appropriate for application on larger spacecraft. Furthermore, most of the CubeSat hardware is designed, built, and tested by student teams under faculty and professional engineering supervision. Students in fact participate in every aspect of a CubeSat project.
Each CubeSat project requires approximately $0.4 million of funding annually. NSF is targeting a continuous queue of six CubeSat projects, with two new starts and two launches each year. This plan will require approximately $2.5 million of sustained annual funding. Current AGS budgets allow for approximately $1.5 million annually. There is therefore a shortfall of about $1 million per year.
The CubeSat program has clearly moved beyond its initial trial phase and has demonstrated great success, particularly in areas of education. As described in Chapter 4 in the “Diversify” recommendations of DRIVE, the survey committee believes that the program deserves its own line of funding at the level necessary to sustain two starts per year. The committee also recommends specific metrics to be employed for assessing the adequacy of the size of the program going forward. The committee is enthusiastic about the prospects of the CubeSat program for contributing to technology development as well as basic research.
As recommended in Chapter 4 in the “Educate” component of DRIVE, the committee endorses the continuation of the successful NSF Faculty Development in Space Sciences (FDSS) program, as well as the development of a complementary curriculum development program. The committee also recommends that 4-year institutions of higher education should be considered eligible for FDSS awards as a means to further broaden and diversify the field, subject to the burden of proof that program objectives pertaining to research education are achievable by the proposing institution. As existing FDSS awards come to term, the program is expected to change, with new awards being staggered to avoid boom-bust faculty hiring cycles. The number of junior faculty in the FDSS queue will likely remain the same, and so the burden on other AGS programs will also remain constant.
The NSF Research Experiences for Undergraduates program is an excellent means to attract talented undergraduates to the field, and the committee has endorsed it in the “Educate” component of DRIVE, along with the various summer school offerings supported by NSF. Currently, these include the annual Polar Aeronomy and Radio Science (PARS) summer school, the AMISR school on incoherent scatter, and CISM. The total allocation for these schools is $200,000 per year. Additional schools take place at the
National Solar Observatory and as part of the annual CEDAR, GEM, and SHINE meetings. The committee notes the particular need for a replacement for the CISM school and also the desirability of providing opportunities for professional development of graduate students via community workshops. In addition, the skills needed to become a successful scientist go beyond such formal discipline training and include interpersonal and communication skills, awareness of career opportunities, and leadership and laboratory management ability. The committee endorses NSF programs that support postdoctoral and graduate student mentoring and recommends that NSF enable opportunities for focused community workshops that directly address professional development skills for graduate students. Finally, the committee endorses programs that specifically target enhancing diversity within solar and space physics, such as the NSF Opportunities for Enhancing Diversity in the Geosciences program.
Solar and space physics is intrinsically multidisciplinary and appears in more than one NSF division or directorate. The National Solar Observatory and the ATST are currently within the Astronomy Division of the Mathematical and Physical Sciences Directorate. The AGS Division within the Geosciences Directorate manages ionospheric and magnetospheric science, but also solar-heliospheric and space weather science. AGS is also the home of the National Center for Atmospheric Research (NCAR) and its High Altitude Observatory (HAO), which supports a broad range of research topics ranging from the Sun to Earth.
The placement of solar and space physics in multiple divisions and directorates arises from the cross-cutting relevance of the science. However, funding for basic research on subjects that are not clearly aligned with one division, and thus have no clear home at NSF, can be difficult to obtain. For example, sun-asa-star and planetary magnetospheric research falls between the AGS and Astronomy divisions. Another timely example is the science of the outer heliosphere. Recent observations of the outer heliosphere by NASA satellites raise fundamental science questions pertaining to the structure of shocks, where and how magnetic reconnection takes place, and how particles are accelerated, all of which are subjects integral to the Sun-Earth-heliosphere system science program. The survey committee recommends in the “Integrate” element of the DRIVE initiative that NSF ensure that funding is available for basic research in subjects that fall between sections, divisions, and directorates, and that in particular the outer heliosphere be considered within the scope of the AGS Division. The committee further calls attention to the importance of maintaining a laboratory program to probe fundamental plasma physics.
Another way to promote cross-disciplinary research is via critical-mass groupings of observers, theorists, modelers, and computer scientists who together target grand-challenge questions in the field of heliophysics, as recommended in “Venture” of the DRIVE initiative. The periodic competition for heliophysics science centers (HSCs) with substantial funding (at the level of $1 million to $3 million per year) will focus attention on the field in a way that is not possible with the present programmatic mix. The NSF Physics Frontier Centers are successful examples that have become highly competitive in the university community and might serve as models for the HSCs. They also have great potential for attracting faculty and students via their focus on exciting and challenging science.
The assets across NSF for solar and space physics are significant. The Astronomy Division of the Directorate for Mathematical and Physical Sciences is the home of the National Solar Observatory, with ongoing synoptic observations and the ATST under construction, and of the National Radio Astronomy Observatory, which includes some solar researchers. The AGS Division of the Geosciences Directorate has championed the CubeSats program, arguably the most innovative development in spaceflight over the past decade. AGS is also the home of solar and space physics research at NSF, both in the Geospace Section and in the NCAR/Facilities Section at HAO, which also runs the Mauna Loa Solar Observatory. AGS has increased its responsibility for the Arecibo Radio Observatory, which remains the largest-aperture telescope in the world for astrophysical, planetary, and atmospheric studies. It has pioneered the utilization of hosted payloads through its involvement with Iridium and Iridium NEXT, serving as a model for NASA in that respect.
The 2010 astronomy and astrophysics decadal survey6 considered the future of NSF-supported solar research in view of its likely expansion in the ATST era. The current funding split, with the majority of grant funding coming from AGS and with the facilities funding divided between AGS and AST, was noted for being unusual and differing from the space-based solar research model. The 2010 report concluded that large facilities like the ATST would benefit from a more unified approach to how the two NSF divisions develop and support ground-based solar physics. It further encouraged NSF to work with the solar, heliospheric, stellar, planetary, and geospace communities to find a way to ensure a coordinated, balanced ground-based solar astronomy program able to maintain multidisciplinary ties. The relevance and importance of these recommendations have not diminished in the intervening time.
A more unified approach to solar and space physics at NSF would help establish the field as a professional discipline. The FDSS program also works in this direction, and the committee has emphasized in DRIVE “Educate” the need for NSF to make solar and space physics an officially recognized subdiscipline of physics and astronomy. Currently it is not listed as a dissertation research area within NSF’s Annual Survey of Earned Doctorates, an omission that influences other rankings, ratings, and the demographic surveys done by the National Research Council and the American Institute of Physics. Ultimately, recognition of solar and space physics as an official subdiscipline will enhance its visibility and the ability to recruit future space scientists.
A comprehensive investigation in solar and space physics cannot take place in isolation but should be part of an international effort, with different countries able to bring to bear unique geographic advantages, observing platforms, and expertise. The research community in the United States is poised to participate in and take advantage of a number of emerging international initiatives that could contribute to the fulfillment of the overall strategy recommended by the survey committee. For example, the international incoherent scatter radar consortium EISCAT is embarking on the EISCAT3D project, a very large, distributed, multistatic, transceiving array that will be able to measure ionospheric state variables in three dimensions through incoherent scatter. The technological, analytical, and logistical challenges that must be addressed to realize EISCAT3D are daunting but could be overcome more easily with the participation of U.S. researchers, who would benefit enormously from access to this prototypical instrument. Another example is the International Space Weather Meridian Circle Program headquartered in China. This ambitious program seeks to fully instrument the 120E and 60W meridian in order to provide a global picture of unfolding space weather
6 National Research Council, New Worlds, New Horizons, 2010.
events. Because they already maintain extensive arrays of space weather monitoring instruments in North and South America, researchers in the United States are natural partners for the program. The addition of the Asian half of the meridian will be useful for distinguishing local-time from storm-time space weather phenomenology.
While participation in international solar and space research projects could be accomplished through numerous individual, bilateral initiatives and agreements, the overall impact would be increased by coordinated agency involvement. The NSF in particular is well situated to help organize U.S. participation in these and other international projects.