WAIT. WHAT???? I thought AL WHORE GORE Said Polar Bears were drowning
and all the coast lines were going to flood because of Global Warming.
er.. Climate Change was melting all of the ice.
NASA REPORT FROM 2014
Sea ice surrounding Antarctica reached a new record high extent this
year, covering more of the southern oceans than it has since scientists
began a long-term satellite record to map sea ice extent in the late
1970s. The upward trend in the Antarctic, however, is only about a third
of the magnitude of the rapid loss of sea ice in the Arctic Ocean.
The new Antarctic sea ice record reflects the diversity and
complexity of Earth’s environments, said NASA researchers. Claire
Parkinson, a senior scientist at NASA’s Goddard Space Flight Center, has
referred to changes in sea ice coverage as a microcosm of global
climate change. Just as the temperatures in some regions of the planet
are colder than average, even in our warming world, Antarctic sea ice
has been increasing and bucking the overall trend of ice loss.
“The planet as a whole is doing what was expected in terms of
warming. Sea ice as a whole is decreasing as expected, but just like
with global warming, not every location with sea ice will have a
downward trend in ice extent,” Parkinson said.
Since the late 1970s, the Arctic has lost an average of 20,800 square
miles (53,900 square kilometers) of ice a year; the Antarctic has
gained an average of 7,300 square miles (18,900 sq km). On Sept. 19 this
year, for the first time ever since 1979, Antarctic sea ice extent
exceeded 7.72 million square miles (20 million square kilometers),
according to the National Snow and Ice Data Center. The ice extent
stayed above this benchmark extent for several days. The average maximum
extent between 1981 and 2010 was 7.23 million square miles (18.72
million square kilometers).
The single-day maximum extent this year was reached on Sept. 20,
according to NSIDC data, when the sea ice covered 7.78 million square
miles (20.14 million square kilometers). This year's five-day average
maximum was reached on Sept. 22, when sea ice covered 7.76 million
square miles (20.11 million square kilometers), according to NSIDC.
A warming climate changes weather patterns, said Walt Meier, a
research scientist at Goddard. Sometimes those weather patterns will
bring cooler air to some areas. And in the Antarctic, where sea ice
circles the continent and covers such a large area, it doesn’t take that
much additional ice extent to set a new record.
“Part of it is just the geography and geometry. With no northern
barrier around the whole perimeter of the ice, the ice can easily expand
if conditions are favorable,” he said.
Researchers are investigating a number of other possible explanations
as well. One clue, Parkinson said, could be found around the Antarctic
Peninsula – a finger of land stretching up toward South America. There,
the temperatures are warming, and in the Bellingshausen Sea just to the
west of the peninsula the sea ice is shrinking. Beyond the
Bellingshausen Sea and past the Amundsen Sea, lies the Ross Sea – where
much of the sea ice growth is occurring.
That suggests that a low-pressure system centered in the Amundsen Sea
could be intensifying or becoming more frequent in the area, she said –
changing the wind patterns and circulating warm air over the peninsula,
while sweeping cold air from the Antarctic continent over the Ross Sea.
This, and other wind and lower atmospheric pattern changes, could be
influenced by the ozone hole higher up in the atmosphere – a possibility
that has received scientific attention in the past several years,
Parkinson said.
“The winds really play a big role,” Meier said. They whip around the
continent, constantly pushing the thin ice. And if they change direction
or get stronger in a more northward direction, he said, they push the
ice further and grow the extent. When researchers measure ice extent,
they look for areas of ocean where at least 15 percent is covered by sea
ice.
While scientists have observed some stronger-than-normal pressure
systems – which increase winds – over the last month or so, that element
alone is probably not the reason for this year’s record extent, Meier
said. To better understand this year and the overall increase in
Antarctic sea ice, scientists are looking at other possibilities as
well.
Melting ice on the edges of the Antarctic continent could be leading
to more fresh, just-above-freezing water, which makes refreezing into
sea ice easier, Parkinson said. Or changes in water circulation
patterns, bringing colder waters up to the surface around the landmass,
could help grow more ice.
Snowfall could be a factor as well, Meier said. Snow landing on thin
ice can actually push the thin ice below the water, which then allows
cold ocean water to seep up through the ice and flood the snow – leading
to a slushy mixture that freezes in the cold atmosphere and adds to the
thickness of the ice. This new, thicker ice would be more resilient to
melting.
That suggests that a low-pressure system centered in the Amundsen Sea
could be intensifying or becoming more frequent in the area, she said –
changing the wind patterns and circulating warm air over the peninsula,
while sweeping cold air from the Antarctic continent over the Ross Sea.
This, and other wind and lower atmospheric pattern changes, could be
influenced by the ozone hole higher up in the atmosphere – a possibility
that has received scientific attention in the past several years,
Parkinson said.
“The winds really play a big role,” Meier said. They whip around the
continent, constantly pushing the thin ice. And if they change direction
or get stronger in a more northward direction, he said, they push the
ice further and grow the extent. When researchers measure ice extent,
they look for areas of ocean where at least 15 percent is covered by sea
ice.
While scientists have observed some stronger-than-normal pressure
systems – which increase winds – over the last month or so, that element
alone is probably not the reason for this year’s record extent, Meier
said. To better understand this year and the overall increase in
Antarctic sea ice, scientists are looking at other possibilities as
well.
Melting ice on the edges of the Antarctic continent could be leading
to more fresh, just-above-freezing water, which makes refreezing into
sea ice easier, Parkinson said. Or changes in water circulation
patterns, bringing colder waters up to the surface around the landmass,
could help grow more ice.
Snowfall could be a factor as well, Meier said. Snow landing on thin
ice can actually push the thin ice below the water, which then allows
cold ocean water to seep up through the ice and flood the snow – leading
to a slushy mixture that freezes in the cold atmosphere and adds to the
thickness of the ice. This new, thicker ice would be more resilient to
melting.
Source:
http://www.nasa.gov/content/goddard/antarctic-sea-ice-reaches-new-record-maximum
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