The Coldest Place in the World
 
Dec. 10, 2013:  What is the coldest place on Earth? It is a high ridge in
Antarctica on the East Antarctic Plateau where temperatures in several hollows
can dip below minus 133.6 degrees Fahrenheit (minus 92 degrees Celsius) on a
clear winter night.
 
Scientists made the discovery while analyzing the most detailed global surface
temperature maps to date, developed with data from remote sensing satellites
including the new Landsat 8, a joint project of NASA and the U.S. Geological
Survey (USGS). Ted Scambos, lead scientist at the National Snow and Ice Data
Center in Boulder, Colo., joined a team of researchers reporting the findings
Monday at the American Geophysical Union meeting in San Francisco.
 
http://www.nasa.gov/sites/default/files/coldestplacerecords.png
 
With remote-sensing satellites, scientists have found the coldest places on
Earth, just off a ridge in the East Antarctic Plateau. The coldest of the cold
temperatures dropped to minus 135.8 F (minus 93.2 C) -- several degrees colder
than the previous record. Image Credit: Ted Scambos, National Snow and Ice
Data Center
Researchers analyzed 32 years' worth of data from several satellite
instruments. They found temperatures plummeted to record lows dozens of times
in clusters of pockets near a high ridge between Dome Argus and Dome Fuji, two
summits on the ice sheet known as the East Antarctic Plateau. The new record
of minus 136 F (minus 93.2 C) was set Aug. 10, 2010.
 
That is several degrees colder than the previous low of minus 128.6 F (minus
89.2 C), set in 1983 at the Russian Vostok Research Station in East
Antarctica. The coldest permanently inhabited place on Earth is northeastern
Siberia, where temperatures in the towns of Verkhoyansk and Oimekon dropped to
a bone-chilling 90 degrees below zero Fahrenheit (minus 67.8 C) in 1892 and
1933, respectively.
 
"We had a suspicion this Antarctic ridge was likely to be extremely cold, and
colder than Vostok because it's higher up the hill," Scambos said. "With the
launch of Landsat 8, we finally had a sensor capable of really investigating
this area in more detail."
 
The quest to find out just how cold it can get on Earth -- and why -- started
when the researchers were studying large snow dunes, sculpted and polished by
the wind, on the East Antarctic Plateau. When the scientists looked closer,
they noticed cracks in the snow surface between the dunes, possibly created
when wintertime temperatures got so low the top snow layer shrunk. This led
scientists to wonder what the temperature range was, and prompted them to hunt
for the coldest places using data from two types of satellite sensors.
 
https://www.youtube.com/watch?v=Hp6wMUVb23c
 
The coldest place on earth is in the East Antarctic Plateau, but not at the
highest peak. Rather, the coldest spots develop just downhill from a ridge
that runs from Dome A to Dome Fuji.
 
They turned to the Moderate Resolution Imaging Spectroradiometer (MODIS)
instruments on NASA's Terra and Aqua satellites and the Advanced Very High
Resolution Radiometer (AVHRR) on several National Oceanic and Atmospheric
Administration satellites. These sensitive instruments can pick up thermal
radiation emitted from Earth's surface, even in areas lacking much heat.
 
Using these sensors to scan the East Antarctic Plateau, Scambos detected
extremely cold temperatures on a 620-mile stretch of the ridge at high
elevations between Argus and Fuji, and even colder temperatures lower
elevations in pockets off the ridge. Then, with the higher resolution of the
Thermal Infrared Sensor (TIRS) aboard Landsat 8, the research team pinpointed
the record-setting pockets.
 
The team compared the sites to topographic maps to explore how it gets so
cold. Already cold temperatures fall rapidly when the sky clears. If clear
skies persist for a few days, the ground chills as it radiates its remaining
heat into space. This creates a layer of super-chilled air above the surface
of the snow and ice. This layer of air is denser than the relatively warmer
air above it, which causes it to slide down the shallow slope of domes on the
Antarctic plateau. As it flows into the pockets, it can be trapped, and the
cooling continues.
 
"By causing the air to be stationary for extended periods, while continuing to
radiate more heat away into space, you get the absolute lowest temperatures
we're able to find," Scambos said. "We suspected that we would be looking for
one magical site that got extremely cold, but what we found was a large strip
of Antarctica at high altitude that regularly reached these record low
temperatures."
 
https://www.youtube.com/watch?v=jlucyyHVXes
 
This narrated animation shows the process by which the coldest place on Earth
develops its extreme low temperatures.  Play it
 
The study is an example of some of the intriguing science possible with
Landsat 8 and the TIRS instrument, which was built at NASA's Goddard Space
Flight Center in Greenbelt, Md. Since its launch Feb. 11, Landsat 8 has
captured approximately 550 scenes per day of Earth's land surface. USGS
processes, archives and distributes the images free of charge over the
Internet.
 
"With Landsat 8, we expect to see more accurate and more detailed maps of the
landscape than we've ever been able to see," said James Irons, the mission's
project scientist at Goddard. "If change is occurring, I think we'll be able
to detect it earlier and track it."
 
Researchers also are eager to see what new results come out of Landsat 8, both
from icy plateaus and Earth's warmer regions.
 
"What we've got orbiting Earth right now is a very accurate and consistent
sensor that can tell us all kinds of things about how the land surface of
Earth is changing, how climate change is impacting the surface of Earth, the
oceans of Earth, and the icy areas of Earth," Scambos said. "Finding the
coldest areas on Earth is just the beginning of the discoveries we're going to
be able to make with Landsat 8."
 
Credits:
Production editor: Dr. Tony Phillips | Credit: Science@NASA
 
More information:
 
NASA's Landsat 8 website:
 
http://www.nasa.gov/mission_pages/landsat/main/index.html
 
 
Regards,
 
Roger

--- D'Bridge 3.96
 * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)