December 13, 2002
NASA study: year-round
Arctic sea ice may vanish
The great-grandchildren
of today’s Nunavummiut may end up living in a radically different natural
environment than the one we know today.
A new study published in
October by researchers from the National Aeronautics and Space Administration
predicts the unthinkable: that year-round Arctic sea-ice may vanish by the end
of this century.
Their work, based on satellite
data gathered between 1978 and 2000, shows that if current melt rates continue,
there may be year-round sea-ice in the Arctic by 2099.
They also found that temperatures
in the Arctic are rising at a rate of 1.2 C per decade, and that sea-ice is
now melting at a rate that’s about nine per cent faster than shown by prior
research.
"If the perennial
ice cover, which consists mainly of thick multi-year ice floes, disapears, the
entire Arctic Ocean climate and ecology would become very different," Josefino
Comiso, the author of the study, told the Environmental News Service.
The NASA study says that
the rate of sea-ice decline in the Arctic is expected to accelerate because
of interactions between the ice, oceans and the atmosphere. As temperatures
in the Arctic rise, the summer ice cover retreats, more solar heat gets absorbed
by the ocean, and more ice gets melted by a warmer upper water layer.
In turn, this will produce
more climate change in the Arctic, and around the globe. Summer sea ice reflects
sunlight out to space, cooling the planet’s surface and warming the atmosphere.
As the ice cover shrinks, less sunlight will be reflected, allowing the sun
to warm more of the ocean.
NASA has also found more
recent data that shows that this year’s perennial ice cover is the least
extensive ever observed in the Arctic during the era of satellite observation.
The NASA study was published
in the late October issue of the Journal Geophysical Research Letters. It was
funded by NASA’s Cryospheric Sciences Program and the NASA Earth Science
Enterprise/Earth Observing System Project.
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December
13, 2002
Alaskans wonder: where’s
winter?
Many Alaskans are wondering
if the earth is tilting differently on its axis this year.
That’s because the
first signs of winter haven’t appeared in most places, even though the
calendar shows it’s well into December.
As of last week, snow had
yet to fall on Alaska’s largest city, Anchorage. In Fairbanks, they’ve
seen freezing rain – but no snow.
On the Arctic coast, shore-fast
ice is slow to form, and many hunters are still unable to go seal hunting on
the ice.
An AP report last week
quoted a National Weather Service meteorologist as saying that the biggest factor
causing this year’s warming trend is El Nino, a large area of water in
the Pacific Ocean that affects wind and water patterns.
A high-pressure ridge on
the British Columbia coast is channeling warm, moist air into Alaska. But weather
officials say global warming may be a factor too.
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