Antarctic and Southern Ocean scientific research has produced many important and exciting scientific advances. Spanning oceanography to tectonics, glaciology to atmospheric chemistry, microbiology to astrophysics—the extreme Antarctic environment provides unique opportunities to expand knowledge about how the planet works and even the very origins of the universe. Research on the Southern Ocean and the Antarctic ice sheets is becoming increasingly urgent for understanding the future of the region and its interconnections with and impacts on many other parts of the globe. Antarctic science has global consequences.
Conducting research in Antarctica has always been a challenging endeavor. Ensuring safe field operations requires significant support, and accessing research bases requires specialized ships, runways carved from ice, aircraft equipped with skis, specialized helicopters, and over-snow vehicles. Despite these challenges, the U.S. National Science Foundation (NSF) provides researchers with broad access to the continent and its surrounding ocean. This research is supported through the three U.S. scientific stations (McMurdo, Amundsen-Scott, and Palmer), two polar research vessels (the Lawrence M. Gould and the Nathaniel B. Palmer), and heavy icebreaker ships that ensure resupply access to stations and continuity of operations. Each year, more than 3,500 Americans are involved in research and logistical activities of the U.S. Antarctic Program (USAP).
The USAP, managed by NSF’s Division of Polar Programs (NSF/PLR), supports U.S. scientific research and related logistics in Antarctica and aboard ships in the Southern Ocean. Although budgets vary from year to year, NSF/PLR invests approximately $70 million annually in scientific research and $255 million annually in infrastructure and logistics to support the research. The level of funding for infrastructure and the high ratio of logistics support personnel to scientists reflect the complexity and challenges of working in the far south.
The NSF requested that the National Academies of Sciences, Engineering, and Medicine convene a committee to develop, through widespread community engagement, a decadal-scale vision for NSF’s Antarctic and Southern Ocean research—including research that is focused on the region itself, as well as research that uses the Antarctic as a unique platform for observing Earth’s space environment and the universe. The Committee sought to identify priorities for strategic investments in compelling re-
search and to identify the infrastructure most critical for supporting this research. (See Appendix B for the full Statement of Task.)
This report builds on a series of USAP advisory efforts in recent years, including a National Research Council study, Future Science Opportunities in Antarctica and the Southern Ocean (NRC, 2011a) and a special Blue Ribbon Panel study, More and Better Science in Antarctica Through Increased Logistical Effectiveness (BRP, 2012). In addition, this report is informed by extensive efforts to gather ideas from a diverse community of researchers across the United States. This included a widely advertised online forum and outreach sessions held at 14 locations across the country and at one international conference. The outreach effort spanned 11 months and engaged over 450 people.
The Committee’s strategic vision for the major components of a robust USAP include the following:
- Continuation of a broad-based program that supports, across all major areas of Antarctic and Southern Ocean science, the curiosity-based research driven by proposals from principal investigators (PIs). The Committee did not attempt to recommend specific priorities for this category of research.
- A collection of larger-scale research initiatives that address particularly compelling scientific questions poised for significant advance but are (in size, cost, and complexity) beyond the scope of a PI-driven project. The Committee recommends here a very limited number of these topics as priorities for support—some of which, we suggest, merit substantial additions to NSF’s existing research budget.
- Foundational elements that enable, support, and add value to all research activities—including core logistical and infrastructure needs (e.g., vessels, aircraft, field gear, research stations, laboratories, data transmission), strategic observational efforts, data management, and education and public outreach. The Committee suggests here an array of actions that NSF could undertake to strengthen these framework elements.
A CORE PROGRAM OF BROAD-BASED INVESTIGATOR-DRIVEN RESEARCH
Investment in a broad portfolio of research is essential for maintaining U.S. leadership in Antarctic and Southern Ocean science, and for ensuring that the nation is well positioned to take advantage of breakthroughs and to respond to new environmental challenges. The NSF/PLR model of supporting research across a broad spectrum of disciplinary areas, in response to proposals from across the research community, continues to be effective in sustaining and stimulating a vibrant scientific enterprise. Many of
the ideas raised in the community input for this study are appropriate and compelling candidates for this category of “bottom-up” PI-driven research. But the Committee felt strongly that it should not define a priori what proposals for individual research projects should be favored; rather, such decisions should instead be left to the standard NSF review process.
In the Antarctic, even small research projects can involve significant logistical requirements for getting scientists into the field, and so it is important for NSF to identify opportunities for efficiency and coordination that best leverage logistical investments. This includes efforts to improve coordination in the collection, management, and analysis of observations. For example, many studies require observations of basic physical parameters (e.g., oceanic or atmospheric conditions), and efficiencies could be gained if these data were better shared among research teams or routinely obtained at key locations for shared use.
Recommendation: NSF should continue to support a core program of broad-based, investigator-driven research and actively look for opportunities to gain efficiencies and improve coordination and data sharing among independent studies.
LARGER-SCALE PRIORITY RESEARCH INITIATIVES
Given the costs and logistical challenges of accessing remote Antarctic and Southern Ocean regions of interest, we suggest that the traditional PI-driven research support be balanced with more directed, large-scale efforts aimed at concentrating a critical mass of human and financial resources on key research goals. Drawing upon both the community input and internal deliberations, the Committee identified, and recommends for consideration going forward, three main priorities for large research initiatives that require a coordinated “push” to make transformative advances, and that are beyond the scope of proposals submitted by individuals or small groups of investigators. To help provide a rigorous process for identifying these priority topics, the Committee developed the following evaluation criteria (Box S-1).
Recommendation: NSF should pursue the following as strategic priorities in Antarctic and Southern Ocean research for the coming decade:
How fast and by how much will sea level rise? The Changing Antarctic Ice Sheets Initiative
- A multidisciplinary initiative to understand why the Antarctic ice sheets are changing now and how they will change in the future.
Evaluation Criteria for Large Research Initiatives
- Compelling science: research that has the potential for important, transformative steps forward in understanding and discovery.
Secondary filters (important criteria, but each one may not be met in every case):
- Potential for societal impact: research that yields information on near-term and/or long-term benefits for society.
- Time-sensitive in nature: research that involves systems/processes undergoing rapid change that need to be observed sooner rather than later; research that could help inform current public policy concerns.
- Readiness/feasibility: research that is poised to move forward quickly within the coming decade, in terms of needed technologies and community readiness.
- Key area for U.S. and NSF leadership: research for which the United States, and NSF in particular, is advantageously positioned to lead.
Tertiary filters (additional factors to consider):
- Partnership potential: research for which NSF/PLR investments could leverage investment by other federal agencies, other parts of NSF, or international partners.
- Impacts on program balance: research that would not cause significant adverse impacts on other projects by requiring disproportionate funding support, or logistical support.
- Potential to help bridge existing disciplinary divides: research that could provide opportunities to bring together disciplinary communities that seldom work together.
- Using multiple records of past ice sheet change to understand rates and processes.
- How do Antarctic biota evolve and adapt to the changing environment? Decoding the genomic and transcriptomic bases of biological adaptation and response across Antarctic organisms and ecosystems.
- How did the universe begin and what are the underlying physical laws that govern its evolution and ultimate fate? A next-generation cosmic microwave background program.
Below is a brief overview of the motivation, goals, and key steps forward for each of these topics. The first of these topics is the largest of the three, and in the Committee’s judgment is the most urgent to pursue.
Strategic Priority I: How Fast and by How Much Will Sea Level Rise? The Changing Antarctic Ice Sheets Initiative
Ice sheets resting upon bedrock below sea level in both West and East Antarctica are vulnerable to a runaway collapse process known as marine ice sheet instability. This instability is thought to be triggered mostly by melting at the ice sheet edges by warm ocean water. Although this process has been identified and tested in models, it has not yet been directly observed; and it is not known how fast this runaway collapse might occur or what parts of the Antarctic ice sheet will be involved. But evidence is building that portions of the Antarctic ice sheet are becoming unstable and beginning to collapse, and that the pace of change has accelerated in recent years. There is an urgent need to understand this process in order to better assess how future sea level rise from ice sheets might proceed.
Understanding why and how the ice is changing now, and how fast it will change in the future, has critical implications for human society. As the West Antarctic Ice Sheet (WAIS) responds to a warming ocean and changing climate, it could contribute 2 to 4 m of global sea level rise within just a few centuries (with additional, much larger potential contributions from the East Antarctic Ice Sheet, but on unknown timescales). Protecting coastal infrastructure and ecosystems from this sea level rise is a massively expensive proposition, and understanding the likely rate and magnitude of sea level rise is critical to evaluating the level of societal response required.
The Committee thus proposes a major new effort to improve understanding of why the marine ice sheets of Antarctica, especially West Antarctica, are changing and how they will change in the future. This would be a multipronged research strategy that includes studies of both the ice sheet changes occurring today and of major ice sheet changes that have occurred in the past.
Component i: A multidisciplinary initiative to understand why the Antarctic ice sheets are changing now and how they will change in the future
There are major gaps in scientific understanding of the processes and rates of ice sheet collapse, stemming from lack of observations in critical areas in the ocean and beneath the ice surface, and from still-evolving understanding of ice sheet/shelf dynamics and of critical changes in Antarctic climate and atmospheric circulation. Understanding the fundamental processes driving Antarctic ice sheet change requires a coordinated research effort with mea-
surements taking place over an extended time in critical regions. The initiative proposed here builds directly upon the recent history of U.S. leadership and investment in West Antarctic research. The key elements of this initiative include
- Multidisciplinary studies of key processes to advance understanding of complex ice, oceanic, and atmospheric interactions;
- Systematic measurement of key drivers of change in West Antarctica, for instance, including in situ observations of atmospheric and oceanic circulation, sea ice changes and influences, ice sheet flow and accumulation, and the sub-ice-shelf and grounding-line environment;
- Mapping the unknown terrains beneath the major ice shelves and the critical regions beneath the ice sheet, with technologies such as airborne radar, geophysical imaging, active seismic surveys, and sub-ice rovers, as well as traditional coastal and on-ice surveys; and
- Advancing development of coupled atmosphere–ocean–sea ice–ice sheet models optimized for the Antarctic environment.
This effort will require improved access to logistically challenging coastal regions of WAIS, which in turn requires research vessel, airlift, aerogeophysical, and over-snow traverse capabilities. It will require new technologies and sampling strategies, including advanced buoys and moorings, and autonomous instrumented submarines and surface sensor stations.
Component ii: Using multiple records of past ice sheet change to understand rates and processes
The detailed physical processes by which ice sheet collapse occurs are not well understood, and this lack of understanding translates directly into model uncertainties on the predicted speed and extent of future WAIS collapse. Resolving these uncertainties requires rigorous study of past rapid ice retreat events. The Committee thus proposes a well-integrated program of ice core, marine, and terrestrial studies that can directly inform and help constrain the models used to predict future evolution of WAIS.
The most recent WAIS collapse event is thought to have happened during the last interglacial period (Eemian) about 125,000 years ago. Paleorecords have been recovered from this period, but the low temporal resolution of these samples has frustrated attempts to constrain the rate of ice sheet collapse. For ice cores, pursuing annually resolved samples may yield particularly valu-
able evidence for establishing how fast Antarctic ice can melt. This initiative thus would include drilling one or more ice cores from sites on the margin of the presumed WAIS collapse region, where ice from the Eemian with annual layers is likely to still be preserved. A potential ice core site that is already well characterized and appears suitable is Hercules Dome, located at the boundary between East and West Antarctica.
This initiative would also include high-resolution sediment cores from marine basins at carefully chosen sites within and adjacent to the suspected WAIS collapse region. High rates of sediment accumulation are expected in open marine conditions; and it is thus reasonable to expect that annually or near-annually resolved intervals from collapse phases of the WAIS can be recovered in carefully selected records, providing new insights on how fast and how much West Antarctic ice melted during key historical intervals.
Determining the geographical footprint of past marine ice sheet loss by mapping the areal extent of the collapse region is also critical to estimating the volume of ice lost and hence the contribution to sea level rise. One promising approach is cosmogenic isotope exposure dating techniques on short bedrock cores taken from beneath the WAIS, which can indicate if the ice sheet was removed during a given time period, and in some cases how long the region was ice-free. These sub-ice datasets, along with cosmogenic and geochronological data from nearby moraines and glacial deposits that record ice margin positions, can be used to assess changes in WAIS ice volume over time.
This proposed Changing Ice Initiative has two main components that are distinct in terms of research strategies and geographical focus, but they cannot be advanced as isolated efforts. Ongoing interaction among these different research communities will yield the innovations that can elevate this initiative above and beyond the West Antarctic research carried out to date.
The USAP has supported a great deal of successful research on the changing Antarctic ice sheets over the past few decades, but the increased urgency of concerns about WAIS collapse necessitates greatly expanded multidisciplinary efforts among the U.S. research community and at the international level—with strong leadership and support from NSF. This research will ultimately provide critical guidance on when, where, and how society should adapt to rising sea levels. Although the costs of this research are large relative to the current budgets for NSF/PLR core programs, they are tiny relative to the projected costs of adaptation to and damage from sea level rise.
Strategic Priority II:
How do Antarctic biota evolve and adapt to the changing environment? Decoding the genomic and transcriptomic bases of biological adaptation and response across Antarctic organisms and ecosystems.
For more than 30 million years, Antarctica and the Southern Ocean have been unique, isolated ecosystems with extreme climate conditions. The organisms confined within the Antarctic region have had to continually evolve to adapt to changing environmental challenges, making Antarctica a vast natural laboratory for understanding organismal evolution. As environmental change progresses, hastened in modern human times by global climate change and commercial fishing, there is compelling urgency to understand how Antarctic species and ecological interactions cope with the selective pressures.
Such questions have been widely studied through molecular biology, physiology, and ecology; but the fundamental unexplored frontier is the genomic information encoded within Antarctic organisms. Genome sequencing of populations of living species will reveal the magnitude of their genetic diversity, which is important in assessing their ability to adapt to environmental change. In addition, decoding transcriptomes and metatranscriptomes can provide information about an organism’s functional plasticity and evolutionary capacity.
The importance of decoding the genomes of key Antarctic organisms to understand evolutionary adaptations and ecological success was recognized over a decade ago (NRC, 2003b). Since then, leaps in technological advances and large drops in costs have made genome sequencing highly feasible, with massively parallel sequencing infrastructures now widely available across research institutions and universities. Given such developments, the field is poised to make new discoveries in the following key areas: (i) Antarctic biodiversity and species interaction as an indication of their evolutionary potential, (ii) species’ functional response to the changing Antarctic environment as an indication of their phenotypic plasticity, and (iii) evolutionary cold adaptation/specialization and future evolutionary and adaptive potential.
This initiative would involve biologists working on diverse species ranging from viruses to mammals, in a coordinated pulse of activity with a shared goal of decoding the genomic and functional bases of organismal adaptation in a changing environment. The effort would be inclusive of genomes and transcriptomes of individual species and species assemblages; and it could encompass ancient DNA, viruses, bacteria, and complex eukaryote species from major Antarctic habitats, including ice sheets, soils, outcropping rocks, surface and subglacial lakes and streams, the ocean, and sea
ice. A priority focus can be given to keystone species and organisms/communities that are fundamentally important for addressing questions about Antarctic adaptation in the past and in the future.
NSF could implement this initiative in a series of calls for proposals designed to encourage interplay among lab-based genomic analyses, field-based environmental investigations, and collection of biological samples and environmental physical data—with concurrent support for bioinformatics advancements to aid in assembling and annotating the genomes to be analyzed.
This initiative can be based in part on analysis of already-archived biological samples, effectively advancing Antarctic biological research without taxing already-overstretched budgets and field logistics.
Strategic Priority III:
How did the universe begin and what are the underlying physical laws that govern its evolution and ultimate fate? A next-generation cosmic microwave background program.
The cosmic microwave background (CMB) is the fossil light from the early universe of nearly 14 billion years ago. Measurements of the CMB have already provided remarkable insights into the makeup of the universe, determining the relative fractions of ordinary matter, dark matter, and dark energy, as well as the presence of the cosmic neutrino background. A key test remains, however—detection of the imprint on the CMB of gravitational waves generated during a process occurring in the first instants of the universe, known as Inflation. Such a detection would not only provide a spectacular confirmation of the Inflationary origin of the universe, it would open a window on physics at energy scales many orders of magnitude greater than could ever be probed with particle accelerator laboratory research, and it would provide evidence of the long-sought, but so far elusive, quantum nature of gravity.
A next-generation experimental program referred to as CMB Stage IV (CMB-S4) has been proposed to provide definitive measurements of the early universe, detecting inflationary gravitational waves, or at least setting limits that rigorously rule out some proposed models. The next generation of CMB measurements would also offer enough sensitivity to make precise determinations of the number and type of neutrino species, as well as the sum of their masses. The precision planned for these next-generation measurements will help unlock the story of the universe’s evolution that as yet remains hidden in the CMB. These experiments address fundamental questions
about our origins and the workings of the natural world that cannot be explained with current understanding of physics and thus demand further investigation.
This project would involve an array on the order of 10 telescopes installed at key locations around the world. Installing some of these telescopes at the South Pole will be a critically important part of the array, because the unique Antarctic environment makes it particularly valuable for obtaining the needed observations. The next-generation CMB experiment will be comparable to the current CMB research, in terms of its logistical “footprint” at the South Pole.
The CMB-S4 studies have been recommended by a major community-scale assessment—the “P5” Particle Physics Project Prioritization Panel, and this is seen as the next logical step in this rapidly progressing field of research. Taking the next step now will ensure U.S. leadership and continued return on NSF’s investment in the South Pole CMB program. This effort would involve three NSF divisions (PLR, Physics, and Astronomical Sciences), the Department of Energy (DOE) Office of Science, and NASA, with potential for international partners as well.
FOUNDATIONS FOR A ROBUST ANTARCTIC AND SOUTHERN OCEAN RESEARCH PROGRAM
The Committee identified the following infrastructure and logistical support needs and other key issues as particularly critical for advancing the priority research initiatives, as well as supporting a wide array of investigator-driven research across PLR’s core programs.
Access to remote field sites. The USAP has long been a leader in supporting deep-field research campaigns, and the community expressed strong desires to see continued support for these world-class capabilities. For the proposed Changing Ice Initiative in particular, it is essential to have expanded access to deep-field sites in West Antarctica, including work around and under the ice sheet edges. Critical target areas for U.S. efforts include the Amundsen Sea sector, the Ross Ice Shelf, and the grounding lines of the Siple Coast. Key needs include a deep-field camp and logistics hub, over-snow science traverse capabilities, ship support for research in ice-covered coastal areas (see below), all-weather aircraft access to McMurdo, and improved aircraft access to remote field locations. Given the reality that there are finite resources to transport material and personnel, careful planning will be needed to ensure that NSF’s currently developing initiative to modernize McMurdo and Palmer stations does not constrain support for deep-field research activities.
Ship support. A prominent theme in the community input for this study was concern about ship-based support for the USAP. The United States currently has very limited heavy icebreaker support for research in Antarctic waters. The USCGC Polar Star is over 40 years old. The Nathaniel B. Palmer is approaching the end of its design service life and regardless is designed for only limited icebreaking. Despite more than a decade of assessment and planning efforts to address these limitations, no significant progress has been made thus far toward the acquisition of a new polar research vessel or icebreaker. This situation limits where U.S. scientists can conduct research and increases dependence on foreign vessels. To support the science priorities recommended by this Committee, and to retain a leadership role in both Antarctic and Arctic research, NSF will need to prioritize the acquisition of a next-generation research icebreaker, and in the near term will need to work with foreign research vessel operators to provide critically needed field opportunities for U.S. scientists. To maintain operations at U.S. Antarctic research stations and support all U.S. research carried out on the continent, progress must be made in acquiring one or more new polar class icebreakers.
Support for sustained observations. Long-term observations are essential for improving understanding of the natural environment and human influences on that environment. A call for expanded NSF support of sustained observational efforts was a common theme in the community input to this study, across widely varying disciplines. Some examples of frequently highlighted observing system needs include the Automatic Weather Station network, seismic and geodetic monitoring around the continent, improved ocean monitoring (e.g., surface and subsurface moorings, profiling floats, gliders), and instrumentation for characterizing long-term changes in solar variability and its impacts. Pursuing a comprehensive observing system across the full Antarctic continent, as recommended in the Future Science Opportunities report (NRC, 2011a), is still a worthwhile long-term goal, yet it simply may not be feasible to pursue at present. However, there are many practical and relatively low-cost steps that can be taken toward this broader goal by better coordinating, integrating, and strategically augmenting the wide array of observational efforts being carried out across the USAP. And the proposed Changing Ice Initiative offers excellent opportunities to develop regional building blocks of a broader Antarctic and Southern Ocean observing system.
Communication and data transmission capacity. Effective communications and information technology are critical to ensure safety in the field, operational support and management of manned and autonomous instrumentation, and daily bulk transmission capacity for scientific data. The proposed CMB-S4 program requires an increase in transmission rate up to the order of 1 terabyte/day in the coming decade. The Changing Ice Initiative raises new requirements for operational communications and bulk
data transmission, for instance from deep-field camps and from autonomous instruments operating under the ice shelf.
Data management. None of the priority science recommended in this report can have lasting value if the underlying data are not preserved and accessible. Data management needs to be supported as an integral part of the scientific effort, which means supporting data itself as a valuable asset. The community input to this study revealed a widespread demand for more open and coordinated data collection and sharing, better use of existing data, and more integration of data across nations, disciplines, and data types. NSF/PLR can help the community sustain and develop data services to meet these demands, building on encouraging recent developments such as the formation of the Antarctic and Arctic Data Consortium and the Polar Data Coordination Network. NSF/PLR cannot address all the challenges alone or immediately, but there are many steps (discussed herein) that could be taken to realize scientific objectives more efficiently.
Coordination opportunities. The Committee’s priority research initiatives all require some degree of new or expanded collaborative efforts among NSF/PLR and other divisions in NSF’s Geosciences directorate (Atmospheric and Geospace Sciences, Earth Sciences, and Ocean Sciences), Directorate of Biological Sciences, and Directorate for Mathematical and Physical Sciences (Physics and Astronomical Sciences). There are also numerous opportunities for expanding NSF/PLR cooperation in key areas with other U.S. federal agencies (especially NASA, DOE, and NOAA), and with other countries’ Antarctic and Southern Ocean research programs. Some areas that seem particularly ripe for expanding collaborative efforts include carrying out aerogeophysical, bathymetric, and seismic mapping exercises; performing biological sampling and survey efforts; planning ice core, marine-sediment, and geological drilling activities; improving representation of Antarctic and Southern Ocean processes in earth system models; expanding environmental sampling and instrument deployment from ships that service the various national bases around Antarctica; and supporting the Long-Duration Balloon studies and other large-scale astronomy/astrophysics and space weather research projects.
Education and public outreach. Antarctic science, with its inherent appeal to people’s sense of discovery, is an underutilized element in educational curricula. NSF/PLR, together with other key partners, has important roles to play in supporting and developing Antarctic-themed resources for educators in K-12 and undergraduate classrooms, and likewise in developing public engagement and outreach resources for an array of informal educational institutions. An emphasis on using Antarctic datasets in classroom exercises and providing engaging experiences (e.g., personal stories from scien-
tists in the field) can help people feel a sense of connection to the Antarctic and better appreciate the scientific and societal value of research in this remote part of the world. NSF can also help provide developmental opportunities in teaching and research for graduate students, postdoctoral researchers, and early-career Antarctic and Southern Ocean scholars—for instance, through targeted funding opportunities for research experiences, including international collaborations and institutional exchange, for undergraduates, graduates, postdocs, and educators.
Recommendation: NSF should prioritize the following actions to advance infrastructure and logistical support for the priority research initiatives recommended here—actions that will likewise benefit many other research activities supported under NSF/PLR’s core programs.
- Develop plans to expand deep-field access in key regions of the West Antarctic and Southern Ocean, including the following key elements: deep-field camp and logistics hub, over-snow science traverse capabilities, ship support for research in ice-covered Southern Ocean coastal areas, all-weather aircraft access to McMurdo, and improved aircraft access to remote field locations.
- Support the efforts of the Coast Guard to design and acquire a new polar-class icebreaker; and with the assistance of other research partners, design and acquire a next-generation polar research vessel. In the near term, work with international partners to provide ocean-based research and sampling opportunities through other countries’ ice-capable research ships.
- Actively pursue opportunities for better coordinating and strategically augmenting existing terrestrial observation networks, and better coordinating national vessels to increase sampling of the Southern Ocean.
- Continue advancing efforts to improve USAP communication and data transmission capacity, including location/navigation for autonomous underwater instrumentation.
- Identify specific archives to manage and preserve data collected in all the core programs; encourage all funded projects to include personnel specifically tasked to address data management needs throughout a project’s planning and execution; and work to both advance Antarctic-specific data management activities and advance cooperation with broader NSF-wide, national, and international data management initiatives.
NSF support for Antarctic and Southern Ocean research is vital for advancing the frontiers of human knowledge across many disciplines, for building an improved basis for understanding the earth system on a global scale, and for informing critical choices about how society might respond to major environmental changes over time. While there is an endless reservoir of exciting and important questions that Antarctic and Southern Ocean research could address, in the face of limited budgets for research and logistical support, the need for prioritization in allocating resources is real. The Committee hopes that the ideas raised here, which were richly informed and inspired by the input of researchers across the country, will provide a useful strategic framework for helping NSF leadership and staff make wise choices for the coming years.