Scientific investigation of Antarctica began on the present scale with the 1957-1958 International Geophysical Year. Since then, continuous research by many nations has come close to completing a reconnaissance of the continent and its surrounding oceans.

The goal is to foster research on worldwide and regional problems of scientific and social importance and to expand fundamental knowledge of the region. Because of the expense of antarctic operations, research is performed in Antarctica only if it can be performed only there or if it can be performed best there.

Investigators from universities and, to a lesser extent, from federal agencies and other organizations perform the research projects. For most Americans who do research in Antarctica the National Science Foundation, on completion of exacting review and selection procedures that include evaluation by outside scientists, provides both financial and operational support. Investigators may perform research and analysis individually, in small teams, or in large interdisciplinary groups.

Preparation and presentation of the results of research in Antarctica are the responsibility of the investigators. These resultes appear mainly in scientific journals.

What follows is a brief description of research objectives in the scientific disciplines most active in Antarctica:

A. Aeronomy and astrophysics

The polar regions have been called Earth's window to outer space. This term originally applied to study of aurora and other phenomena related to interaction of solar plasmas and fields. In this context the polar upper atmosphere is a screen on which the results of such interactions can be viewed and through which other evidence of space physics processes can pass. Today, this concept of Earth's polar atmosphere as a window includes research in other fields as well. With discovery of polar stratospheric ozone depletions, a window previously thought ``closed'' (the ultraviolet window) is known to ``open'' in certain seasons. In astronomy and astrophysics, favorable atmospheric conditions and the unique location of the South Pole enable scientists to use this window to probe the structure of the Sun and the universe with unprecedented precision.

The aeronomy and astrophysics program supports studies of three regions:

o the stratosphere and the mesosphere. Research focuses on stratospheric chemistry and aerosols, particularly in the context of the ozone hole. The polar stratosphere is expected to be a field of continued interest and growth.

o the thermosphere, the ionosphere, and the magnetosphere. These regions derive many of their characteristics from the interplay of ionized plasmas and energetic charged particles with geomagnetic and geoelectric fields. The upper atmosphere, particularly the ionospheric portion of it, is the ultimate sink of solar wind energy that is transported into the magnetosphere. En- ergy dissipates in the ionosphere because of particle precipitation, which is the result in part of resonant wave- particle interactions, and because of the Joule heating that is a result of currents driven by electric fields.

o astronomy and astrophysical studies of the regions of the universe outside the magnetosphere, including solar astronomy and cosmic ray physics. Astrophysical studies are primarily conducted at the South Pole station, and long-duration balloon projects are launched from McMurdo.

Major goals are to sponsor research that requires or would benefit from the unique conditions of the Antarctic, to contribute to understanding of the role of the Antarctic in global environmental change, to participate in interdisciplinary studies of geosphere- biosphere interactions in the middle and upper atmosphere, and to improve understanding of the coupling of the Earth's polar atmosphere with the magnetosphere and of the ways in which both are affected by solar activity.

B. Biology and medical research

The goal of antarctic biology and medical research is to improve understanding of life phenomena and processes. The program supports projects directed at all levels of organization from molecular, cellular, and organismal to communities, ecosystems, and global processes. Investigators should apply recent theory and technology to understanding how organisms, including humans, adapt and live in high latitude environments and how ecosystems may respond to global change. Support is focused on these areas:

o Marine ecosystem dynamics. Understanding the natural variability of marine ecosystems is the goal. An important direction is toward correlating the structure and function of the marginal ice-zone ecosystem with oceanic and atmospheric processes. Of particular interest is the influence of nutrient limitations on primary production and the role of marine phytoplankton in carbon dioxide cycling. Proposals to develop data collection technologies such as satellite remote sensing are encouraged.

o Terrestrial and limnetic ecosystems. Organisms in ice-free areas and in perennially ice-covered lakes show remarkable adaptations. The presence of relatively few species eases the study of ecosystem dynamics and the interpretation of experiments. Research is needed on adaptive mechanisms and evolutionary proces- ses. Studies that include molecular biological approaches are encouraged.

o Population biology and physiological ecology. Research is supported in population dynamics, especially metabolic, physiological, and behavioral adaptations of krill and other zooplankton and fish species. Marine mammals and birds have been the object of much research and merit further attention in some areas. Mechanisms necessary for maintenance of cell function in fishes and their feeding behavior are important topics. Long-term observations are needed to improve understanding of manmade or natural changes.

o Adaptation. The extremes of light, temperature, and moisture have resulted in unusual adaptations. Research topics include low temperature photosynthesis and respiration, enzymatic adaptations, adaptive strategies such as development of antifreeze compounds and modifications to circulation systems, and the response of organisms to increased UV-B from the ozone hole. Biotechnology offers unique approaches to addressing questions involving adaptation, and such applications are of special interest.

o Human behavior and medical research. Antarctica's extreme climate can induce social, psychological, and physiological stresses, particularly during the winter isolation, which can exceed 8 months. Research has applications to human health and performance both in the Antarctic and in other isolated environments such as spacecraft. Studies can focus on topics such as epidemiology, thermal regulation, immune system function, individual behavior, and group dynamics.

C. Earth sciences

Antarctica represents about 9 percent of Earth's continental crust and has been in a near-polar position for more than 100 million years. It is covered by a continental ice sheet with an average thickness of 3 km. There is unequivocal evidence that for a long period after the continent arrived at its high-latitude position, extensive continental ice sheets did not exist there. The ice sheets, through their interaction with and effect on oceanic and atmospheric circulation, play a key role in modulating global climate.

Some important program goals include:

o determining the tectonic evolution of Antarctica and its relationship to the evolution of the continents from Precambrian time to the present

o determining Antarctica's crustal structure

o determining the effect of the dispersal of antarctic con- tinental fragments on the paleocirculation of the world oceans, on the evolution of life, and on global paleoclimates and present cli- mate

o reconstructing a more detailed history of the ice sheets, identifying geological controls to ice sheet behavior, and defining geological responses to the ice sheets on regional and global scales

o determining the evolution of sedimentary basins within the continent and along continental margins

All of these problems involve the need for an improved understanding of where, when, and how Antarctica and its surrounding ocean basins were accommodated in the interplate movements inferred from studies of global plate kinematics. In short, the program encourages investigation of the relationships between the geological evolution of the antarctic plate and paleocirculation, paleoclimate, and the evolution of high-latitude biota.

In geophysics, the continent and its environs have a central role in the geodynamic processes that have shaped the present global environment. The tectonic role of the antarctic continent in the breakup of Gondwanaland, the close interaction of the antarctic crust and ice sheet with their attendant effects on the planet's fluid systems, and Antarctica's present-day seismically quiescent role defines the important thrusts of geophysical research in the high southern latitudes. Modern geophysical and logistical technology might focus on three broad ``transect zones,'' across the Weddell and Ross embayments and in the area of the Amery Ice Shelf, where prospects for broad-scale understanding of the region are highest.

D. Ocean and climate systems

Antarctic oceanic and tropospheric studies focus on the structure and processes of the ocean-atmosphere environment and their relationships with the global ocean, the atmosphere, and the marine biosphere. As part of the global heat engine, the Antarctic has a major role in the world's transfer of energy. Its ocean/atmosphere system is known to be both an indicator and a component of climate change.

Research sponsored by the ocean and climate systems program is intended to improve understanding of the oceanic environment at high latitudes, including global exchange of heat, salt, water, and trace elements, sea-ice dynamics, and tropospheric chemistry and dynamics. Major program elements include--

o Physical oceanography, concerned with understanding the dynamics and kinematics of the polar oceans, the effects of interface driving forces such as wind, solar radiation, and heat exchange, water mass production and modification processes, ocean dynamics at the pack ice edge, and the effect of polynyas on venti- lation.

o Chemical oceanography, concerned with chemical composition of sea water and its global speciation, reactions among chemical elements and compounds in the ocean, fluxes of material within ocean basins and at their boundaries, and the use of chemical tracers to study time and space scales of oceanic processes.

o Sea ice dynamics, including study of the material charac- teristics of sea ice down to the individual crystal level and the large-scale patterns of freezing, deformation, and melting. These processes have implications for both atmospheric and oceanic ``climates.'' Advances in instrumentation, including remote sensing or telemetering of ice type, thickness, motion, and growth, should enable large scale dynamics of sea ice to be monitored over long periods.

o Meteorology, concerned with atmospheric circulation systems and dynamics. Research areas include the energy budget; atmos- pheric chemistry; transport of atmospheric contaminants to the Antarctic; and the role of large and mesoscale systems in global exchange of heat, momentum, and trace constituents.

E. Glaciology

Snow and ice are pervasive elements of high latitude environmental systems and have an active role in the global environment. The glaciology program is concerned with the study of the history and dynamics of all naturally occurring forms of snow and ice, including floating ice, seasonal snow, glaciers, and continental and marine ice sheets. Program emphases include paleoenvironments from ice cores, ice dynamics, numerical modeling, glacial geology, and remote sensing of ice sheets. Some specific objectives are:

o Correlation of climatic fluctuations evident in antarctic ice cores with data from arctic and lower-latitude ice cores, and integration of the ice record with the terrestrial and marine record.

o Documentation of the geographic extent of climatic events noted in paleoclimatic records; and the extension of the ice core time series to provide information on astronomical forcing of climate.

o Establishment of more precise dating methodologies for deep ice cores.

o Determination of the Cenozoic history of antarctic ice sheets and their interaction with global climate and uplift of the Transantarctic Mountains; response of the antarctic ice sheets to the Pliocene warming.

o Investigation of the physics of fast glacier flow with emphasis on processes at glacier beds.

o Investigation of ice-shelf stability.

o Identification and quantification of the feedback between ice dynamics and climate change.

A Polar Ice Coring Office is supported by the National Science Foundation to service the technological requirements of glaciologists. It focuses on ice drill development for NSF- supported remote field projects.

A National Ice Core Laboratory processes, catalogs, distributes, and archives ice core samples. The University of Colorado and the Geological Survey operate the facility in Denver under contract to NSF.

F. Environmental research

This program supports research that can help to reduce further the environmental impact of NSF's activities in Antarctica. Areas of inquiry include policy research, effects of past practices, materials and waste management, impacts, resilience of ecosystems, and promising technologies.

G. Instrumentation

Supporting complex, state-of-the-art, multidisciplinary research in the Earth's most remote and hostile region is a challenge met increasingly by instrumentation. Off-the-shelf instruments, highly capable computers, and support for the development of new instruments are requested frequently in research proposals.

Some existing instruments are well-suited for polar regions; they can gather data year-round at low operational cost. Use of these instruments can reduce the number of people required to make measurements and even increase the reliability of the collected data. Unattended instruments for collection and analysis of data are essential in Antarctica, where the extreme environment, great distances, and logistics constraints limit the spatial and temporal extent of coverage.