The polar regions contain nearly a fifth of the worlds land area, two-thirds
of its freshwater, nearly all its ice, the largest desert, the biggest ocean
current, one entire continent, one entire ocean, the driest air, millennia of
human occupation and, of course, the coldest climates. They present an extraordinary
range of opportunities for research opportunities that are being realized
with the aid of developments in technology, logistics support and international
collaboration even as continuing research expands the range of new opportunities.
The spectrum of current scientific activity ranges from paleoclimatology to
Sea ice covers much of the Arctic Ocean, and an ice sheet 2.2 kilometers thick covers nearly all the Antarctic continent. The ice itself is an important factor in the global climate, and its study continues to provide key clues to past and possible future climate change. Ice cores from the Greenland ice sheet obtained by U.S. and European researchers provided convincing evidence that profound climate change occurred in the past on time scales as short as a decade. Antarctic ice cores obtained in a collaboration of Russian, French and U.S. scientists revealed cyclic climate changes that correlate with changes in Earths orbit over the last 420,000 years.
Current and planned European, Japanese and U.S. efforts in Antarctica both will extend the record back in time and help determine if the changes in the Arctic and Antarctic were simultaneous. In parallel, scientists continue to study ice streams that drain the Greenland and Antarctic ice sheets, and glaciers in Alaska and elsewhere, partly to determine if they will raise global sea level.
As valuable as the ice has been in providing information about climate change, it also has hindered gaining a deeper knowledge of solid-earth history. Not until the late 1990s, when the National Science Foundation (NSF) equipped nuclear submarines with swath bathymeters, was it possible to map the floor of the Arctic Ocean beneath the ice to any significant degree for research purposes. The resultant maps enabled a study of the Gakkel Ridge that revealed unexpected volcanic and hydrothermal vent activity around this slow-spreading subsea ridge discoveries that will be followed with geological drilling and searches for living organisms near the vents.
At Cape Roberts in Antarctica, researchers from seven nations collaborated to obtain sediment cores beneath the ice. These cores revealed a subpolar climate with tundra-like vegetation between 34 and 25 million years ago, together with glacial climate cycles correlated to changes in Earths orbit some 24 million years ago. A new international project, ANDRILL, will recover continental margin sediments in Antarctica from the inception of the Antarctic ice sheet 35 million years ago through its waxing and waning over the subsequent 20 million years, spanning the transition from greenhouse to icehouse conditions on Earth.
A substantial fraction of polar research is multidisciplinary, in large measure because of the emphasis on understanding the drivers of global climate. The multidisciplinary approach is exemplified in the Arctic by the SHEBA program (Surface Heat Budget of the Arctic), which studied how heat fluxes that couple the atmosphere, sea ice and ocean produce feedbacks that affect Arctic and global climate. A successor program, SEARCH (Study of Environmental Arctic Change), will involve a dozen or more U.S. agencies and a range of international collaborators. SEARCH began this year with an NSF-led solicitation for proposals addressing the arctic freshwater cycle. This project also looks at the human element. Arctic change increasingly affects arctic residents, and native peoples have brought substantial understanding of natural cycles both as participants and as hosts of research projects.
Another new international activity, the Arctic-Subarctic Ocean Flux Program (ASOF), will measure flows between the Arctic and the global ocean to study cold deep-water formation and the transport of energy via the global ocean conveyer belt. In the Antarctic, initial analyses and modeling of data from the GLOBEC (Global Ocean Ecosystem Dynamics) program demonstrated the importance of the Southern Ocean in the global carbon cycle. Planning for future international research in the Southern Ocean is in progress. What is essential to the study of both polar oceans is development and deployment of improved technology both for navigating below the ice and for transporting data by real-time telemetry from moorings, automated underwater vehicles, gliders and floats.
In all these examples, integrating, synthesizing and modeling data are proving to be as important to scientific understanding as collecting data. But progress hinges on obtaining more comprehensive and better data.
Multidisciplinary research has taken on new dimensions with the realization that polar regions harbor unusual ecosystems containing organisms that somehow have adapted to the extreme environment. Current research is yielding fundamental insights into how the geophysical environment shapes ecosystems and how adaptations at the molecular level enable the organisms to survive and reproduce. Polar regions are not the sterile wastelands they were once thought to be, and this realization has led to increased interest in both terrestrial and aquatic ecosystems at high latitudes, including the subglacial lakes that the Antarctic ice sheet has shielded from the surface biosphere for millions of years.
The developments highlighted above, together with others in research areas as diverse as space weather and astrophysics, have taken polar science into a new era of exploration. Continued development of communications, transportation, instrumentation and remote sensing capabilities will be essential to realizing the opportunities before us.
Agencies around the globe funding global research face common challenges: to work together to provide the tools we need to probe emerging ideas; and to ensure that succeeding generations of scientists also emerge to exploit those ideas.