1
Introduction

The Antarctic and its surrounding ocean are remote, harsh, and unique environments that lend themselves to serve as natural laboratories, and the science supported in Antarctica is providing critical insights into how Earth and the surrounding universe operate. Antarctica contains 70 percent of Earth’s freshwater in its ice sheets,¹ an equivalent of 58 meters of global mean sea level if melted (Morlighem et al., 2020). The continent is surrounded by the planet’s strongest ocean current, which plays a significant role in structuring atmospheric, marine, evolutionary, and ice sheet mass loss processes. How Antarctica changes in the future will play a large role in global climate patterns that will have significant impacts on humanity. The unique and continually evolving conditions have resulted in the continent being set aside as for international cooperation for scientific research as outlined in the Antarctic Treaty.

Antarctica is experiencing accelerating ice mass loss due to climate change and warming oceans (Shepherd et al., 2018), and theoretical instabilities make its significant marine-based parts particularly vulnerable to rapid ice loss and collapse. The circulation of the Southern Ocean’s circumpolar current along the continental shelf plays an important role in ice sheet stability and coastal glacial melt, particularly for the West Antarctic Ice Sheet (WAIS) where ocean temperatures can range from 2-4°C. Warmer circumpolar ocean currents that reach underneath the ice shelves and grounding lines² through seafloor troughs can accelerate glacial retreat, leaving ice sheets vulnerable to rapid disintegration and collapse (Jacobs et al., 2011; Schmidtko et al., 2014; Rintoul et al., 2016; Rintoul, 2018; Milillo et al., 2019; Rignot et al., 2019; Smith et al., 2020; Joughin et al., 2021; Wåhlan et al., 2021). There is clear evidence of increasing ice flow, ice thinning, and glacial retreat in many sectors around the continent (Rignot et al., 2013; Paolo et al., 2015; Scambos et al., 2017; Silvano et al., 2019; Smith et al., 2020; Joughin et al., 2021). DeConto et al. (2021) projected Antarctic contributions to sea level rise from ice sheet melting ranging from a median of 8 cm by 2100 with 1.5°C warming to 34 cm by 2100 (1 m by 2125 and 9.6 m by 2300) under a more extreme warming scenario (Representative Concentration Pathway [RCP] 8.5). The Intergovernmental Panel on Climate Change (2019) estimated global sea level rise of 29 to 110 cm this century, with the uncertainty at the end of the century mainly determined by the ice sheets, especially in Antarctica. Sea level rise threatens coastal communities worldwide, including many of Earth’s megacities (Brown et al., 2013).

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¹ See https://www.nsf.gov/geo/opp/antarct/science/icesheet.jsp.

² Grounding lines are where glaciers detach from the sea floor and become afloat.

The extreme cold and arid conditions of Antarctica with prolonged dark-light cycles have resulted in unique evolutionary solutions for organisms to survive (e.g., Eastman, 1993; Iakovenko et al., 2015). With these adaptations, life occupies the entire continent, spanning ice, rock, soil, sediment, ocean water, sea ice, meltwater ponds, and subglacial environments (e.g., Cary et al., 2010; Christner et al., 2014; Cavicchioli, 2015). The ecosystems have sustained themselves through significant climate transitions (Convey et al., 2008; Thatje et al., 2008). Study of these biological innovations provides insights to limits of conditions for life, and provides potential analogs for life beyond this planet (Abyzov et al., 2006; Goordial et al., 2016).

The Southern Ocean plays a prominent role in global biogeochemistry. The strong westerly winds around the continent result in large divergence and upwelling zones in the surrounding ocean. Upwelling near the continent can represent up to 80 percent of global deep water return to the surface, bringing carbon from the deep ocean back into contact with the atmosphere (Lumpkin and Speer, 2007; Talley, 2013; Gruber et al., 2019a). Additionally, the Southern Ocean contains large regions of ocean downwelling that can account for roughly up to 50 percent of the global ocean’s atmospheric carbon intake (Froelicher et al., 2015; Ito et al., 2015). Recent observations suggest wind intensity is increasing (Gruber et al., 2019b; Ribal and Young, 2019; Goyal et al., 2021), which could increase the release of carbon to the atmosphere and potentially flip the Southern Ocean from being a sink to becoming a source of carbon to the atmosphere.

Antarctica’s remote location and relatively small human presence provides a baseline for global changes in atmospheric composition. The relatively isolated atmosphere combined with its extreme radiative seasonality leads to unique phenomena such as the infamous ozone hole (Farman et al., 1985). The cold dry atmosphere also offers an unparalleled location for astrophysics research. The conditions allow for detection of the microwave background, providing insights into the origin and evolution of the universe (see also Chapter 4). The IceCube Neutrino Observatory, spanning a cubic kilometer of ice, enabled the first detection of nearly massless subatomic neutrinos (Aarsten et al., 2014).

The Antarctic provides this singular location on Earth for scientific discovery across multiple disciplines and is a major focus for science and infrastructure for many nations. As evidence of shifts in Earth’s climate grows, the role of Antarctica and the Southern Ocean in global change is becoming increasingly apparent. The continued sense of discovery and awe, together with the increasingly urgent need to understand how these complex systems work, motivates the pursuit of science in Antarctica.

NSF SUPPORT FOR ANTARCTIC RESEARCH

The U.S. Antarctic Program (USAP) supports scientific research and related logistics on behalf of the United States and is managed by the National Science Foundation’s (NSF’s) Antarctic Sciences Section of the Office of Polar Programs.

These efforts are complemented by the international community to meet the obligations of the Antarctic Treaty that sets aside the continent for scientific research. The goal of the program is to:

• Expand fundamental knowledge of Antarctic systems, biota, and processes,
• Improve understanding of interactions between the Antarctic region and global systems, and
• Utilize the unique characteristics of the Antarctic region as a science observing platform.³

The Antarctic Sciences Section has an annual research budget of approximately $71 million, between 2016 and 2020 (P. Cutler, NSF, personal communication, 2021). Additionally, NSF provides funding to support the USAP facilities and logistical support for funded research. Between 2016 and 2020, total annual funding for Antarctic facilities and logistical support has ranged from $269 million to $303 million.⁴ This facilities and logistics funding supports three Antarctic research stations—McMurdo Station on the Ross Sea, Palmer Station on Anvers

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³ See https://www.nsf.gov/funding/pgm_summ.jsp?pims_id=5519.

⁴ See https://www.nsf.gov/about/budget/fy2018/pdf/26_fy2018.pdf, https://www.nsf.gov/about/budget/fy2019/pdf/30_fy2019.pdf, https://www.nsf.gov/about/budget/fy2020/pdf/30_fy2020.pdf, and https://nsf.gov/about/budget/fy2021/pdf/30_fy2021.pdf.

Island, and Amundsen-Scott Station at the South Pole (see Figure 1-1). A 10-year McMurdo Antarctic Infrastructure Modernization for Science (AIMS) project, funded separately by NSF’s Major Research Equipment and Facilities Construction account, began construction in 2019; in addition to addressing the aging infrastructure, a goal of this completely redesigned facility is to provide flexibility to adapt to changing science needs.⁵ AIMS will require the deployment of many construction workers and the movement of resources, which will have some impact on science deployments as the overall logistics capacity of the USAP is ultimately limited. NSF also funds the use and maintenance of aircraft (primarily LC-130s; see Box 1-1), transport vehicles, and ships for logistical support (see Box 1-2 and Figure 1-3).⁶ These resources are available to support both NSF-funded research and research conducted by other federal agencies.

The USAP deploys roughly 3,000 people to Antarctica every year to conduct scientific research or to provide support to researchers through the operation and maintenance of the research stations and vessels. Although the majority of science is conducted during the austral summer, science is conducted year round. This model has provided a sustained U.S. research presence in Antarctica for decades,

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⁵ See https://future.usap.gov/what-is-aims.

⁶ See https://www.nsf.gov/geo/opp/support/ships.jsp for more information.

supporting large expeditionary science, sustaining extended monitoring programs, and providing infrastructure that supports research across many federal agencies, nongovernmental organizations, and researchers.

NATIONAL ACADEMIES’ 2015 STRATEGIC PRIORITIES

In 2015, the National Academies of Sciences, Engineering, and Medicine released the consensus report A Strategic Vision for NSF Investments in Antarctic and Southern Ocean Research (NASEM, 2015), which was developed with input from more than 400 scientists around the country. The report recommended, “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.” Additionally, the report highlighted three strategic opportunities for NSF:

The report also recommended actions that NSF could undertake to strengthen its foundational elements that enable and support all research activities—including logistical and infrastructure needs (e.g., vessels, aircraft, field gear, research stations, laboratories, data transmission), education, and public outreach. NASEM (2015) included recommendations to improve coordination of a wide array of observations, enhance data management and data transfer technology, and collaborate with other divisions of NSF, U.S. federal agencies, and international partners. The following sections provide additional detail on the 2015 strategic priority areas.

Broad Investigator-Driven Research Program

The NASEM (2015) strategic vision for a robust USAP included “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 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 addition to continued support for a broad core program of investigator-driven research, the report recommended that NSF actively look for opportunities to gain efficiencies and improve coordination and data sharing among independent studies.

Priority I: The Changing Antarctic Ice Sheets Initiative

The West Antarctic Ice Sheet and some major basins of the East Antarctic Ice Sheet have sectors located upon reverse-sloped bedrock that lie below sea level and are potentially vulnerable to runaway collapse. The Changing Antarctic Ice Sheets Initiative prioritizes research that helps determine how fast and by how much sea level will rise with climate change. The priority consists of two interrelated components:

1. understanding current and future change in Antarctic ice sheets, and
2. analyzing multiple records of past ice sheet change to understand rates and processes.

Component i

Priority I, Component i (I.i) involves a multidisciplinary initiative to understand fundamental processes driving change in Antarctic ice sheets now and in the future. NASEM (2015) recommended this research component to address “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.” Key elements 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 rates, 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, and climate models optimized for the Antarctic environment. (NASEM, 2015)

Priority I.i was envisioned to build on recent investments in West Antarctic research, although was not limited to that region. NASEM (2015) stated, “A large East Antarctic marine-based ice sheet project is not suggested as part of the Changing Ice Initiative, but it is important to note that there are compelling research needs and opportunities in that part of the continent.”

Component ii

Studies of past ice sheet collapse are needed to resolve model uncertainties on the rates and extent of future ice sheet collapse. As the second major component of the Changing Ice Initiative, NASEM (2015) proposed an integrated program of sediment and ice core studies seeking improved temporal resolution of the most recent West Antarctic Ice Sheet (WAIS) collapse that may have occurred about 125,000 years ago. The initiative was envisioned in NASEM (2015) to include “one or more ice cores from sites on the margin of the presumed WAIS collapse region,” such as the Hercules Dome site, and “high-resolution sediment cores from marine basins at carefully chosen sites within and adjacent to the suspected WAIS collapse region.” Additionally, work to outline the geographical footprint of past ice sheet loss

was envisioned, including cosmogenic data from short bedrock cores from beneath the WAIS and cosmogenic and geochronological data from glacial deposits. These data would inform and test the models used to predict future ice sheet melting.

Priority II: Decoding the Genomic and Transcriptomic Bases of Biological Adaptation and Response Across Antarctic Organisms and Ecosystems

The terrestrial and marine ecosystems of Antarctica provide a vast landscape and natural laboratory to study the evolution and adaptation of life to extreme cold, dark, ice-covered winter, and the potential to adapt to changing ocean habitat conditions, including temperatures, stratification, and pH. Antarctica offers a research environment to study the adaptation of organisms—from viruses to whales—to extreme and changing environments over geological time and better understand the vulnerability and resilience of Antarctic life to ecosystem change.

NASEM (2015) recognized that genomic, transcriptomic, and other omic information were powerful, yet unrealized assets that could be used to identify the diversity and endemicity of Antarctic life forms, understand their evolutionary history and adaptive characteristics, and explore the adaptive potential of organisms with regards to present day change. In light of recent technological advances, NASEM (2015) noted that the field was “poised to make new discoveries in the following key areas: (i) Antarctic biodiversity and species interaction as an indication of 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 adaptive potential.” The 2015 report proposed an Antarctic genomics initiative to tackle the goal of decoding the genomic and functional basis of organismal adaptation in a changing environment through analysis of existing samples, new collection of biological samples and environmental data, and field-based experimentation. The report also called for support for bioinformatics advancements. NASEM (2015) recognized that advancing U.S. leadership in this area would require a “concerted and well-executed initiative” to generate the needed data.

Priority III: A Next-Generation Cosmic Microwave Background Program

The third priority highlighted in NASEM (2015) focused on improving the sensitivity of CMB measurements to detect gravitational waves generated during the formation of the universe and “provide evidence of the long-sought, but so far elusive, quantum nature of gravity.” To detect inflationary gravitational waves, or at least to set strong limits on large-field inflationary models, NASEM (2015) stated that a next-generation ground-based CMB experimental program known as CMB Stage IV (CMB-S4) was needed. The project would also enable “precise determinations of

the number and type of neutrino species, as well as the sum of their masses.” (NASEM, 2015).

CMB-S4 involves an array of telescopes of two types—smaller apertures (~0.5 m diameter) and larger apertures (5-6 m in diameter)—located at the South Pole and the high Atacama desert in Chile. The most sensitive observations would come from the South Pole, given the superior atmospheric observing conditions, and Chilean telescopes would provide more sky coverage. CMB-S4 would build on research and infrastructure investments made as part of ongoing South Pole CMB research and would complement the continuation of the Long Duration Balloon CMB programs. NASEM (2015) noted that infrastructure upgrades at the South Pole would be required for CMB-S4, including power and data transmission capacity.

STUDY TASK

The recommendations of the 2015 study have become an important touchstone for the NSF OPP Antarctic Program in recent years. To track its progress toward these strategic priorities, NSF requested that the National Academies appoint a committee of experts to conduct a mid-term assessment of the 2015 Strategic Vision recommendations. The committee was asked to:

• Assess progress in addressing research goals outlined in the 2015 report, and
• Identify significant recent advances in scientific understanding and/or technical capabilities (e.g., observational, analytical, computational) that present important new opportunities for progress in addressing the mission of NSF’s Antarctic Sciences Section.

In addition, for the three priority research topics in particular, the committee was asked to:

• Address any current implementation challenges in advancing these research areas, and
• Suggest strategies to overcome these implementation challenges.

This mid-term assessment was not charged to revisit or redefine these scientific priorities or to recommend new priorities. The committee was not tasked to assess progress toward the other recommendations of NASEM (2015), such as infrastructure, logistics, and data management. Although the committee considered logistics as one of many factors that could impact progress toward the research goals outlined in the 2015 report, the committee was not tasked or constituted to conduct a thorough review of logistics,

To conduct the study, the full committee met virtually 11 times over the course of the 15-month study to receive briefings from NSF and to develop the report. The committee also held numerous subgroup meetings, including eight

virtual community engagement meetings. Each community engagement meeting was focused on one specific research priority highlighted in NASEM (2015), to gather input on these questions from the broader research community as well as experts from the specific disciplines. The committee held two Priority I web conferences with the scientific community (one on Priority I.i and a separate meeting on Priority I.ii), with each attracting more than 50 attendees. On Priority II, the committee held three web conferences (with a total of 52 scientists), including one meeting with Antarctic researchers and two meetings with a range of outside experts in genomics and organismal adaptation. On Priority III, the committee solicited written feedback from researchers in the field and held a web conference for additional discussion, with overall input from 11 researchers. The committee also held two web conferences with a total of 16 Antarctic researchers to discuss core-funded research. Overall, these meetings spanned disciplinary expertise, age (from pre-tenured to senior faculty), and the national and international community. The committee received data on OPP funded projects but did not have access to data on proposals that were submitted and declined or details regarding OPP research and logistics planning and prioritization, although the report discusses concerns raised by the scientific community in these areas.

The committee recognizes that Antarctic research efforts have been impacted dramatically by the COVID-19 pandemic since early 2020. Ship and aircraft operations were severely curtailed reflecting the logistical and safety concerns for the scientists and contractors. The committee primarily focused its mid-term assessment of progress toward the strategic priorities on efforts between 2015 and March 2020. The committee recognizes that the pandemic posed significant impacts on the science enterprise overall, and especially on Antarctic field science, beginning in March 2020.

The committee was not charged or constituted to address pandemic logistical and public health strategies, and given the continually evolving health risks and strategies, the committee judged that any near-term recommendations for pandemic response related to Antarctic research would likely be outdated by the time of report release. Instead, the committee focused its recommendations broadly on the remaining 5 years of the decadal strategic vision, understanding that NSF will need to consider these recommendations in the context of funded research efforts have been postponed or delayed due to the pandemic and public health risks that are continuing to evolve.

METRICS FOR COMMITTEE EVALUATION

In the evaluation of progress for each priority (see Chapters 2-5), the committee reviewed several key questions and considered qualitative and quantitative metrics for each. The committee’s evaluation is based on data provided by NSF, feedback from the scientific community, information from scientific

literature, and the collective judgment of the committee. Key questions and metrics included:

• Progress toward science goals: Is the funded research on track to make transformative scientific advances, consistent with the vision of NASEM (2015)? Is there sufficient logistical support for the scientific priorities? Is the program responsive to recent advances in scientific understanding and/or technical capabilities? The committee also considered evaluating the number of publications derived from funded programs as a metric of scientific contributions, but decided that in most cases the lag time for publication meant this was not a useful indicator over the past 5 years.
• Promotion of research priority: Were the NASEM (2015) science priorities effectively communicated and promoted in announcements of opportunities for funding? Was there a targeted call for proposals?
• Science funding: Are there changes in the numbers of proposals funded and amount of funding allocated (2011-2015 versus 2016-2020) to support the three priorities? Is funding being allocated in a way that advances the strategic priorities effectively, considering their scope and breadth?
• Scientific community: Has the scientific community mobilized effectively to advance the strategic priorities? Has the community developed an implementation plan with goals? Are there processes in place to improve coordination and engagement across the scientific community, including multiple disciplines, to address the priorities (e.g., workshops, a science office)? Is there an improvement in the accessibility of NSF funding to junior researchers and researchers from diverse backgrounds to work on the strategic priorities? Are the data generated from funded work available to the broader community in a timely fashion and with appropriate standards to advance priority science?
• Partnerships: Is there sufficient effort/growth in cross-agency collaboration/partnerships and international partnerships to support the science goals?

REPORT ORGANIZATION

The committee’s task is addressed in the next five chapters. Chapters 2, 3, and 4 review progress toward Priorities I, II, and III, respectively, and discuss implementation challenges and opportunities to address them. In Chapter 5, the committee evaluates the potential impacts of the priorities on the broad Antarctic research portfolio, outside of the priority areas. In Chapter 6, cross-cutting opportunities are addressed.

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