Subject: NSF Press Release-Global Change
From: Dot Baker <[email-masked]>
To: [email-masked]
Date: Fri, 08 Nov 91 10:51 EST

Hi Paul,
   Please post to the NIH Listserver as:
      Global.911108
 ---------------------------- Text of forwarded message -----------------------
Title       : STUDIES OF GLOBAL CHANGE
              HIGHLIGHT 1991-1992 ANTARCTIC RESEARCH
NSF Contact : OLPA
Type        : Press Release
Date        : October 4, 1991

 

 
Jeffrey Norris                                       For Release:
(202) 357-9498                                    October 4, 1991
                                                     NSF PR 91-90
 
                    STUDIES OF GLOBAL CHANGE
             HIGHLIGHT 1991-1992 ANTARCTIC RESEARCH

     The National Science Foundation-managed U.S. Antarctic
Program (USAP) has begun its 35th consecutive season supporting
research by scientists on the only continent without permanent
human inhabitants.
     Exceptionally cold, windy, high and dry Antarctica is a
focus of study not only for its own uniqueness, but also because
processes that are revealed there may portend global changes --
in ecosystems, temperature, ice cover, sea level, or entire land
masses -- across a broad range of time scales.
     Changes in phytoplankton blooms from year to year, in animal
populations over decades, in ice-sheet flow and ocean circulation
over centuries and millennia, in the movement of continental
plates over eons, and in stars and galaxies over billions of
years will all be under investigation.
     "Antarctica contributes to our understanding of ecological
and environmental problems, such as global climate change and
ozone depletion," says Robert Corell, NSF assistant director for
geosciences.   "The ice and geology of the continent contain a
record of natural global change processes as they occurred in the
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past, and may continue to occur in the future.  By studying the
ongoing interactions between the atmosphere, the ocean, the ice
and the marine ecosystem of Antarctica, we can learn how these
interactions may in turn affect climate globally."
 
     This season, the United States is fielding 112 scientific
and technical projects, to be conducted by 490 scientists and
technicians at 18 remote field camps and three stations.  These
research outposts include: the busiest in Antarctica, McMurdo
Station, on the Ross Sea; Amundsen-Scott South Pole Station,
supplied by flights from McMurdo; and Palmer Station, on the west
Antarctic Peninsula.
 
     Once again, researchers will be working under an ozone hole.
During September, ozone over the South Pole was depleted more
rapidly than ever before, with levels declining to about
10 percent of normal at some altitudes in the lower stratosphere.
NSF-supported scientists will continue to study the antarctic
ozone hole and the potential impact on life forms of the extra
ultraviolet light that reaches Earth as a consequence of ozone
depletion.
 
     Ten projects will focus on learning more about mechanisms
related to ozone depletion.  In recent years researchers have
discovered that when temperatures in the antarctic stratosphere
dip below -112 degrees Fahrenheit, ice-crystal clouds form.  These clouds
provide a locus where, in the presence of sunlight, chlorine freed from CFCs and
other gases can catalyze the destruction of ozone.
 
     Throughout this research season, scientists will be tracking
changes in temperature, humidity, air circulation, cloud cover,
and crucial chemical compounds, at a range of altitudes, in order
to learn more precisely how these factors affect ozone
destruction.
 
     To examine biological impacts, Deneb Karentz of the
University of California, San Francisco, will continue her
studies on molecules produced naturally by antarctic algae and
invertebrates that protect them from damage due to ultraviolet
light.  In another project, Patrick J. Neale of the University of
California, Berkeley, has originated techniques which he will use
to measure inhibition of photosynthesis by ultraviolet light of
various wavelengths.
 
     To generalize results of these studies on marine organisms
to entire ecosystems, researchers need to know how much
ultraviolet light reaches the Earth over large geographic areas.

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Catherine Gautier of the University of California, Santa Barbara,
has developed a model that will enable scientists to make these
estimates by extrapolating from extensive satellite data on
visible light reflected back into space from Earth's atmosphere
and from clouds.  Gautier will also make ground-based
measurements of visible light at Palmer Station, and will check
her model with these data and with data from UV monitoring
stations at Palmer, McMurdo and the South Pole.
 
     Another area of ongoing ecological research is penguin
studies.  At least one location on the South Shetland Islands off
the Antarctic Peninsula, Adlie and chinstrap penguin populations
have declined over the past few years, according to biologists
Wayne and Susan Trivelpiece of Old Dominion University in
Norfolk, Virginia.
 
     The Trivelpiece team will continue to monitor penguin
colonies at this site and attempt to determine whether the recent
population declines represent natural fluctuations and responses
to the environment, or if they instead might be due to other
events or trends, such as the rise of commercial krill fisheries,
which harvest the penguins' favorite food.
 
     Focusing on longer time scales, glaciologists are
investigating potential changes in ice stability.  At the
conclusion of the last ice age, part of the North American ice
sheet anchored over Hudson Bay collapsed, and led to a rapid rise
in sea level.  Theoretical studies suggest that such marine-based
ice sheets are generally susceptible to collapse.  Today the West
Antarctic Ice Sheet is the only remaining marine-based ice mass
in the world.
 
     In an effort to determine the stability of this ice sheet,
Charles R. Bentley of the University of Wisconsin, Ian M.
Whillans of Ohio State University's Byrd Polar Research Center,
Robert Bindschadler of the National Aeronautics and Space
Administration and Robert Jacobel of St. Olaf College will lead
studies of ice movement on the eastern edge of the Ross Ice
Shelf.
 
     U.S. glaciologists will also travel to the Soviet station
Vostok, where temperatures have dipped to -129 degrees
Fahrenheit.  Here, high on the plateau of the massive continental
ice sheet covering east Antarctica, snow has fallen undisturbed
over the ages, compacting into layers of ice extending downward
over 3,000 meters to bedrock.
 
     Cores of ice extracted from the plateau contain a record of
past climate more than 160,000 years old.  Michael Bender of the
University of Rhode Island and Eric Saltzman of the University of
Miami will study gases trapped in this frozen archive for clues
 
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to past atmospheric composition and biological productivity.  The
researchers will investigate the possibility that changes in the
abundance of marine life may affect the global climate system.
 
     In another U.S.-Soviet collaboration, 10 U.S. scientists
will join 10 Soviet researchers in February to establish the
first manned research station on floating antarctic ice.  The
team will be transported by the Soviet ship, Akademik Federov,
and in one its first missions, a new USAP research ship, the 300-
foot Nathaniel B. Palmer, is scheduled to resupply the ice camp
in April.  The Soviet and U.S. ships plan to pick up the team in
June.
 
     The scientists will drift more than 400 miles on an ice floe
in the Weddell Sea over five months, learning about how ice cover
affects ocean circulation and climate.  Below the ice of the
western Weddell, the water chills, sinks and then spreads along
the Southern Ocean sea floor, supplying cold bottom-water to most
of the world's oceans.  The extent to which the Southern Ocean is
covered by ice waxes and wanes with the seasons.  Winter sea ice
can cover about eight million square miles, an area more than
twice that of the entire United States, and it plays an important
role in heat transfer.  By February the sea ice may melt back to
about one million square miles.
 
     The antarctic land mass, however, was not always covered by
ice.  This year, geologists from New Zealand and the United
Kingdom will join U.S. scientists led by Ian Dalziel of the
University of Texas at Austin in looking back to an ice-free time
200 million years ago, before Antarctica existed as a distinct
polar continent.
 
     Antarctica was once joined with other land masses in an
ancient southern supercontinent called Gondwanaland.  The
researchers will search for clues to determine how today's land
masses once fit together and then split apart over time, changing
ocean circulation and climate.
 
     Other scientists will be in Antarctica investigating natural
phenomena beyond Earth.  The South Pole will once again be a
major site for ground-based astrophysics research.  Astro-
physicists in Antarctica also will be launching air-borne
experiments to learn about solar activity and about changes which
have taken place in the universe over billions of years.
 
     In December, two 28-million-cubic-foot helium balloons will
circle the South Pole at about 78 degrees latitude for ten days
or more, bearing aloft experiments designed to detect energetic
photons and subatomic particles.
 
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     Constant daylight will prevent extreme diurnal temperature
fluctuations and enable the balloons to maintain nearly stable
altitude for the duration of the flights.  Circumpolar air
currents will carry the balloons around the continent and should
permit recovery of the payloads on land.
 
     The balloons will float at 120,000 feet, essentially in
space.  The instruments they carry will register collisions with
subatomic particles that would be absorbed by the Earth's
atmosphere and could not be detected on the ground.
 
     A team led by Robert Lin of the University of California at
Berkeley and colleagues from other institutions will take
advantage of the current peak in the periodic cycle of solar
activity to study solar flares, sudden bursts of energy released
from small areas on the sun's surface.  The team's detector will
register gamma rays and x-rays emitted by the flares, and the
researchers will use the data to investigate the causes of these
solar disturbances.
 
     In addition, Lin's team will study Supernova 1987A, an
explosion first observed in February 1987, in a companion galaxy
to the Milky Way called the Large Magellanic Cloud.  Supernova
1987A was the closest supernova to Earth in 300 years, and it
continues to provide observers with information about how stars
evolve.
 
     Astrophysicists believe that heavy elements, such as the
iron which makes up the Earth's core, are created when a star
collapses on itself and then explodes in a supernova.  X-rays and
gamma rays are emitted during the formation of elements and
provide clues to the processes of stellar evolution.
 
     In a separate experiment and balloon launching, scientists
led by Michael Salamon of the University of Utah and Steve Ahlen
of Boston University will use a one-meter-diameter super-
conducting magnet cooled by a vat of liquid helium in order to
detect cosmic rays.
 
     Heavy cosmic rays, such as the nuclei of iron and cobalt,
come in a variety of isotopes, which can be identified by the way
they are bent in a magnetic field.  By studying the ratios of
these isotopes, the researchers hope to make new discoveries
about changes that stars undergo.
 
                              -end-
 
     The National Science Foundation is an independent agency of
the federal government established in 1950 to promote and advance
scientific progress in the United States.  NSF accomplishes its
mission primarily by competitively awarding grants to educational
institutions for research and education in the sciences,
mathematics, and engineering.
 
..stis file is pr9190
..expires April 1992
 
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