http://www.sciam.com/article.cfm?cha...6783414B7F0000

Launching weather balloons has been a nearly daily habit at some Antarctic
research facilities since 1957. Carrying radiosondes--instruments that
measure atmospheric conditions such as temperature and wind speed--the
balloons travel as high as 12 miles or more. A new analysis of the past 30
years of records from nine research stations, including Amundsen-Scott at
the South Pole, reveals that the air above the entirety of Antarctica has
warmed by as much as 0.70 degree Celsius per decade during the winter
months.

John Turner of the British Antarctic Survey and his colleagues report in
today's issue of Science that this warming trend is consistent across data
from multiple stations run by multiple countries using multiple types of
instruments. Previous studies had shown that Antarctica's surface
temperatures had warmed by roughly 2.5 degrees C over the last half century,
but this study provides the most complete look at atmospheric trends to
date.

"The rapid surface warming of the Antarctic Peninsula and the enhanced
global warming signal over the whole continent shows the complexity of
climate change," Turner says. "Greenhouse gases could be having a bigger
impact in Antarctica than across the rest of the world and we don't
understand why."

This warming has implications for snowfall on the continent as well as the
melting of land-based ice reserves, potentially leading to global sea-level
rise, the researchers warn. Although they cannot ascribe a particular cause
to the warming, they ruled out several other potential explanations,
including heat transfer from other regions (there was no observed change in
wind patterns) and solar radiation changes (the sun is either at or below
the horizon throughout the winter months in question).
And although current computer models fail to predict this warming trend, the
scientists argue that the data is consistent with what would be expected as
a result of increasing greenhouse gases. "Our next step," Turner says, "is
to try to improve the models." --David Biello

Related article.
http://www.sciam.com/article.cfm?cha...6783414B7F0000

Climate Model Predicts Greater Melting, Submerged Cities

Over the past 30 years, temperatures in the Arctic have been creeping up,
rising half a degree Celsius with attendant increases in glacial melting and
decreases in sea ice. Experts predict that at current levels of greenhouse
gases--carbon dioxide alone is at 375 parts per million--the earth may warm
by as much as five degrees Celsius, matching conditions roughly 130,000
years ago. Now a refined climate model is predicting, among other things,
sea level rises of as much as 20 feet, according to research results
published today in the journal Science.

Modeler Bette Otto-Bliesner of the National Center for Atmospheric Research
in Boulder and paleoclimatologist Jonathan Overpeck of the University of
Arizona matched results from the Community Climate System Model and climate
records preserved in ice cores, exposed coral reefs, fossilized pollen and
the chemical makeup of shells to determine the accuracy of the computer
simulation. Roughly 130,000 the Arctic enjoyed higher levels of solar
radiation, leading to increased warming in the summer and the retreat of
glaciers worldwide. The model correctly predicted the extent of the
resulting Arctic ice melt, enough to raise sea levels by roughly nine feet.

"Getting the past climate change correct in these models gives us more
confidence in their ability to predict future climate change," Otto-Bliesner
says. "These ice sheets have melted before and sea levels rose. The warmth
needed isn't that much above present conditions."
But sea levels rose as much as 20 feet 130,000 years ago and Overpeck
speculates that may have been the result of additional melting in
Antarctica. After all, the ice there is not all landlocked; some rests in
the ocean and a little warming in sea temperatures could melt it or pry it
loose. And this time around, the warming is global, rather than concentrated
in the Arctic. "In the Antarctic, all you have to do is break up the ice
sheet and float it away and that would raise sea level," he says. "It's just
like throwing a bunch of ice cubes into a full glass of water and watching
the water spill over the top."


Such a sea level rise would permanently inundate low-lying lands like New
Orleans, southern Florida, Bangladesh and the Netherlands. Already sea level
rise has increased to an inch per decade, thanks to melting ice and warm
water expansion, according to Overpeck. And evidence that the Arctic is
exponentially warming continues to accumulate. Indeed, in another paper in
the same issue of Science, Goran Ekstrom of Harvard University reported a
marked increase in so-called glacial earthquakes (seismic events recorded
throughout the world when Greenland's glaciers slip past rock) since 2002.
In fact, last year alone saw twice as many quakes as in previous years, with
most of that increase coming during the summer months.
"We need to start serious measures to reduce greenhouse gases within the
next decade," Overpeck says. "If we don't do something soon, we're committed
to [13 to 20 feet] of sea level rise in the future." --David Biello

http://www.sciencedaily.com/releases...1125050151.htm

"Volcano Of Fire" Could Be Entering Its Most Dangerous Phase In Nearly A
Century, UB Expert Says

BUFFALO, N.Y. -- The eruption of Colima volcano -- also known as Volcan del
Fuego, or "Volcano of Fire" -- that began on Nov. 20 has produced its first
pyroclastic flows that could signal the start of the volcano's most
dangerous period since its catastrophic eruption in 1913, a University at
Buffalo volcanologist says.

Michael F. Sheridan, Ph.D., professor and chair of the UB Department of
Geology and a co-author of the current hazards map of Colima, says that
while activity at the volcano may continue in "fits and starts," the weak
condition of the volcano summit, combined with the weight of lava that is
now emerging, has created an extremely unstable situation.
Two nearby villages, Yerba Buena and Juan Baragan, were evacuated last week.

In Spring 1991, computer simulations developed by Sheridan accurately
predicted the course and magnitude of pyroclastic avalanches from Colima
that occurred shortly afterward.

Last month, at the annual meeting of the Geological Society of America,
Sheridan reported that extremely fast-moving volcanic mudflows could
inundate and destroy a large part of a key industrial town located northeast
of Colima sometime within the next 10 years.

That would be the case, he says, only if a major explosion should occur as a
result of pent-up pressure at the volcano's summit, and if a blanket of
volcanic ash from the volcano was mobilized by torrential rains, which could
come next spring or earlier.

"While there is still considerable uncertainty whether the current activity
is a prelude to a major event, all of the precursors, such as the lava
emission at the summit and the formation of pyroclastic flows, have already
occurred," Sheridan says.
There is fresh magma at the summit and the slope is very steep, he adds.

"As magma surges upward, the volcano swells and unstable slopes begin to
crumble and slide, becoming avalanches," he says. "This mixture of older,
cool lava and new, red-hot magma can become fluidized and cascade down the
volcano's sides at speeds of 100 miles per hour or more."

According to Sheridan, this could produce incandescent dust clouds so thick
that people caught in them can die from severe burns or suffocation.

He adds that Colima currently is emitting 4,000 tons of sulfur per day,
enough to produce a significant cooling effect on the global climate if the
eruption continues.

A pioneer in developing computerized simulations of volcanoes that allow
researchers to estimate how fast and how far ash flows from an eruption will
travel, Sheridan has been honored by the University of Colima for his
scientific work on the activity of the volcano and for his training of young
Mexican scientists at UB and elsewhere.

The most dangerous volcano in Mexico, Colima has erupted violently three
times during the past 450 years. About 2,300 years ago, it produced a
cataclysmic avalanche much larger than that of Mount St. Helens in 1980.

"Bart Senior" .@. wrote in message ...
http://www.sciencedaily.com/releases...1125050151.htm

"Volcano Of Fire" Could Be Entering Its Most Dangerous Phase In Nearly A
Century, UB Expert Says

BUFFALO, N.Y. -- The eruption of Colima volcano -- also known as Volcan
del Fuego, or "Volcano of Fire" -- that began on Nov. 20 has produced its
first pyroclastic flows that could signal the start of the volcano's most
dangerous period since its catastrophic eruption in 1913, a University at
Buffalo volcanologist says.

Michael F. Sheridan, Ph.D., professor and chair of the UB Department of
Geology and a co-author of the current hazards map of Colima, says that
while activity at the volcano may continue in "fits and starts," the weak
condition of the volcano summit, combined with the weight of lava that is
now emerging, has created an extremely unstable situation.
Two nearby villages, Yerba Buena and Juan Baragan, were evacuated last
week.

In Spring 1991, computer simulations developed by Sheridan accurately
predicted the course and magnitude of pyroclastic avalanches from Colima
that occurred shortly afterward.

Last month, at the annual meeting of the Geological Society of America,
Sheridan reported that extremely fast-moving volcanic mudflows could
inundate and destroy a large part of a key industrial town located
northeast of Colima sometime within the next 10 years.

That would be the case, he says, only if a major explosion should occur as
a result of pent-up pressure at the volcano's summit, and if a blanket of
volcanic ash from the volcano was mobilized by torrential rains, which
could come next spring or earlier.

"While there is still considerable uncertainty whether the current
activity is a prelude to a major event, all of the precursors, such as the
lava emission at the summit and the formation of pyroclastic flows, have
already occurred," Sheridan says.
There is fresh magma at the summit and the slope is very steep, he adds.

"As magma surges upward, the volcano swells and unstable slopes begin to
crumble and slide, becoming avalanches," he says. "This mixture of older,
cool lava and new, red-hot magma can become fluidized and cascade down the
volcano's sides at speeds of 100 miles per hour or more."

According to Sheridan, this could produce incandescent dust clouds so
thick that people caught in them can die from severe burns or suffocation.

He adds that Colima currently is emitting 4,000 tons of sulfur per day,
enough to produce a significant cooling effect on the global climate if
the eruption continues.

A pioneer in developing computerized simulations of volcanoes that allow
researchers to estimate how fast and how far ash flows from an eruption
will travel, Sheridan has been honored by the University of Colima for his
scientific work on the activity of the volcano and for his training of
young Mexican scientists at UB and elsewhere.

The most dangerous volcano in Mexico, Colima has erupted violently three
times during the past 450 years. About 2,300 years ago, it produced a
cataclysmic avalanche much larger than that of Mount St. Helens in 1980.

I actually went on a trip to climb Colima, but ran into trouble with
authorities. It's a small volcano.

Check out what Mt Erebrus dumps into the atmosphere.

Lloyd

"Bart Senior" .@. wrote in message ...
http://www.sciam.com/article.cfm?cha...6783414B7F0000

Launching weather balloons has been a nearly daily habit at some Antarctic
research facilities since 1957. Carrying radiosondes--instruments that
measure atmospheric conditions such as temperature and wind speed--the
balloons travel as high as 12 miles or more. A new analysis of the past 30
years of records from nine research stations, including Amundsen-Scott at
the South Pole, reveals that the air above the entirety of Antarctica has
warmed by as much as 0.70 degree Celsius per decade during the winter
months.

John Turner of the British Antarctic Survey and his colleagues report in
today's issue of Science that this warming trend is consistent across data
from multiple stations run by multiple countries using multiple types of
instruments. Previous studies had shown that Antarctica's surface
temperatures had warmed by roughly 2.5 degrees C over the last half
century, but this study provides the most complete look at atmospheric
trends to date.

"The rapid surface warming of the Antarctic Peninsula and the enhanced
global warming signal over the whole continent shows the complexity of
climate change," Turner says. "Greenhouse gases could be having a bigger
impact in Antarctica than across the rest of the world and we don't
understand why."

This warming has implications for snowfall on the continent as well as the
melting of land-based ice reserves, potentially leading to global
sea-level rise, the researchers warn. Although they cannot ascribe a
particular cause to the warming, they ruled out several other potential
explanations, including heat transfer from other regions (there was no
observed change in wind patterns) and solar radiation changes (the sun is
either at or below the horizon throughout the winter months in question).
And although current computer models fail to predict this warming trend,
the scientists argue that the data is consistent with what would be
expected as a result of increasing greenhouse gases. "Our next step,"
Turner says, "is to try to improve the models." --David Biello



Here's the accuracy of a modern radiosonde:

http://www.aber.ac.uk/ozone/UFAM/UFAM_radiosonde.html


Great paper on innaccuracies over the years from radiosonde temperature
measurement and calculation:

http://www.cru.uea.ac.uk/cru/pubs/th...e/chapter2.pdf


Lloyd