BOX 4.1

Major Discoveries and Findings from Polar Science

  • The presence and cause of the “ozone hole”

  • The molecular and genetic mechanisms of living systems for coping with freezing conditions

  • The Southern Ocean’s role in driving the deep ocean “conveyor belt”

  • Characterization of climate and effects in both the Arctic and the Antarctic

  • Biological isolation as a fundamental force in the evolution of life

  • A record of past climate changes in ice cores and sedimentary sequences

  • Unique views of our universe and clues to its formation

  • Organic pollutant transport to polar food webs and persistence

  • The slowest spreading center and thinnest oceanic crust on Earth

  • Subglacial environments and hydrological systems beneath ice sheets

  • Paleo outbursts of subglacial waters as a geomorphologic agent of change

  • Meteorological observations critical to weather prediction

areas. To this end, a network of stations, field camps, laboratory facilities, ships, airplanes, observing networks, and other support infrastructure has been developed over the years in both the Arctic and the Antarctic.

Essential to these operations is access through and operation ice-covered oceans and coastal seas. The support of polar research requires ships of various icebreaking capabilities, including those that are the subject of this report. This chapter highlights some of the major research themes being pursued in polar science, demonstrating the value provided by this work to the nation. A glimpse of where this science will go in the future is also provided. The scientific value justifies the significant investment needed for polar research to continue and indeed flourish over the next several decades. Simply put, access to the polar regions is fundamentally important if the United States is to continue to be a leader in polar science. Icebreakers are a key part of the necessary infrastructure: They are needed to conduct science in Arctic waters and to open a channel to allow resupply of McMurdo Station (and, in turn, South Pole Station and inland sites) in Antarctica.

ARCTIC SCIENCE

The Arctic Ocean is surrounded by land, with much of the terrain and adjacent shorelines difficult to reach because of ice and challenging weather conditions. Routes to coastal areas are from the south; there are few roads, rail lines, or airports, and there are few or no infrastructure or support facilities along the coast. The conduct of science on land and in coastal areas tends to be based at a few sparsely distributed, remote outposts. In many cases, ships are the most reliable means of access. To date, research that uses icebreakers has focused either on ocean or coastal processes, although icebreakers may be employed to bring sophisticated science assets to remote Arctic terrestrial localities. For example, the Swedish icebreaker ODEN was used to deliver scientific equipment and personnel to remote terrestrial sites in the Arctic during the Swedish “Beringia 2005” expedition. The Coast Guard icebreaker HEALY routinely supports biological, sea ice, marine geological and geophysical, oceanographic, and atmospheric studies.

Life in the Arctic

Arctic biological research addresses basic questions about the role of the Arctic in the global carbon cycle, arctic biodiversity, and adaptations of living systems to cold environments. A multiyear study of biological production and transport of carbon from the Bering and Chukchi Sea shelves to the ocean basin north of Alaska has been conducted from icebreakers. Shelf-basin transport is relatively poorly understood and is hypothesized to play a significant role in the global carbon system. Arctic Basin biodiversity is being studied as part of the Exploration of the Seas and the Census of Marine Life programs. Other programs are studying the ability of polar organisms to avoid freezing and to withstand the formation of ice in their body fluids.

Animals in the Arctic do not freeze to death when their core body temperature falls as low as 2°C but return to a metabolically active state when the body’s heat-generating mechanisms are activated. Many polar insects and plants attain even lower cell temperatures, yet their cells remain ice-free because of antifreeze compounds in their biological fluids (NRC, 2004). Some polar animals and plants experience ice formation in extracellular fluids and yet appear to be undamaged. The knowledge gained from studies of the mechanisms that regulate freezing of extracellular water and protect against damage from ice formation will continue to advance our knowledge of cryotechnologies and biomedicine. An already important application is improvement in methods for low-temperature storage of biological materials, ranging from isolated cells to intact organisms (NRC, 2004). Understanding mechanisms of freezing resistance has broad technological applications in agricultural science (e.g., design of freeze-resistant crops) and biomedicine (e.g., development of improved cryopreservation techniques) (NRC, 2004).

Geology and Geophysics

Exploration of the Gakkel Ridge is shedding light on how new ocean crust is formed and tectonic plates are



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