Landsat 8 helps unveil the coldest place on Earth

Scientists recently recorded the lowest temperatures on Earth at a desolate and remote ice plateau in East Antarctica, trumping a record set in 1983 and uncovering a new puzzle about the ice-covered continent.

Ted Scambos, lead scientist at the National Snow and Ice Data Center (NSIDC), and his team found temperatures from -92 to -94 degrees Celsius (-134 to -137 degrees Fahrenheit) in a 1,000-kilometer long swath on the highest section of the East Antarctic ice divide.

The measurements were made between 2003 and 2013 by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on board NASA's Aqua satellite and during the 2013 Southern Hemisphere winter by Landsat 8, a new satellite launched early this year by NASA and the U.S. Geological Survey.

"I've never been in conditions that cold and I hope I never am," Scambos said. "I am told that every breath is painful and you have to be extremely careful not to freeze part of your throat or lungs when inhaling."

The record temperatures are several degrees colder than the previous record of -89.2 degrees Celsius (-128.6 degrees Fahrenheit) measured on July 21, 1983 at the Vostok Research Station in East Antarctica. They are far colder than the lowest recorded temperature in the United States, measured at -62 degrees Celsius (-79.6 degrees Fahrenheit) in Alaska, in northern Asia at -68 degrees Celsius (-90.4 degrees Fahrenheit), or even at the summit of the Greenland Ice Sheet at -75 degrees Celsius (-103 degrees Fahrenheit).

Scambos said the record temperatures were found in several 5 by 10 kilometer (3 by 6 mile) pockets where the topography forms small hollows of a few meters deep (2 to 4 meters, or 6 to 13 feet). These hollows are present just off the ice ridge that runs between Dome Argus and Dome Fuji -- the ice dome summits of the East Antarctic Ice Sheet. Antarctic bases sit on each of the sites and are generally not occupied during Antarctic winters.

Under clear winter skies in these areas, cold air forms near the snow surface. Because the cold air is denser than the air above it, it begins to move downhill. The air collects in the nearby hollows and chills still further, if conditions are favorable.

"The record-breaking conditions seem to happen when a wind pattern or an atmospheric pressure gradient tries to move the air back uphill, pushing against the air that was sliding down," Scambos said. "This allows the air in the low hollows to remain there longer and cool even further under the clear, extremely dry sky conditions," Scambos said. "When the cold air lingers in these pockets it reaches ultra-low temperatures."

"Any gardener knows that clear skies and dry air in spring or winter lead to the coldest temperatures at night," Scambos said. "The thing is, here in the United States and most of Canada, we don't get a night that lasts three or four or six months long for things to really chill down under extended clear sky conditions."

Centuries-old ice cracks

Scambos and his team spotted the record low temperatures while working on a related study on unusual cracks on East Antarctica's ice surface that he suspects are several hundred years old.

"The cracks are probably thermal cracks -- the temperature gets so low in winter that the upper layer of the snow actually shrinks to the point that the surface cracks in order to accommodate the cold and the reduction in volume," Scambos said. "That led us to wonder what the temperature range was. So, we started hunting for the coldest places using data from three satellite sensors."

More than 30 years of data from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA Polar Orbiting Environmental Satellite (POES) series gave Scambos a good perspective on what the pattern of low temperatures looked like across Antarctica.

"Landsat 8 is still a new sensor, but preliminary work shows its ability to map the cold pockets in detail," Scambos said. "It's showing how even small hummocks stick up through the cold air."

Scambos suspected they would find one area that got extremely cold. Instead they found a large strip at high altitude where several spots regularly reach record low temperatures. Furthermore, dozens of these extremely cold areas reached about the same minimum temperatures of -92 to -94 degrees Celsius (-134 to -137 degrees Fahrenheit) on most years.

"This is like saying that on the coldest day of the year a whole strip of land from International Falls, Minnesota to Duluth, Minnesota to Great Falls, Montana reached the exact same temperature, and more than once," Scambos said. "And that's a little odd."

A physical limit

The scientists suspect that a layer in the atmosphere above the ice plateau reaches a certain minimum temperature and is preventing the ice plateau's surface from getting any colder.

"There seems to be a physical limit to how cold it can get in this high plateau area and how much heat can escape," Scambos said. Although an extremely cold place, Antarctica's surface radiates heat or energy out into space, especially when the atmosphere is dry and free of clouds.

"The levels of carbon dioxide, nitrogen oxide, traces of water vapor and other gases in the air may impose a more or less uniform limit on how much heat can radiate from the surface," Scambos said.

Scambos and his team will continue to refine their map of Earth's coldest places using Landsat 8 data. "It's a remarkable satellite and we've repeatedly been impressed with how well it works, not just for mapping temperature but for mapping crops and forests and glaciers all over the world," Scambos said.

"The uses for Landsat 8 data are broad and diverse," said James Irons, Landsat 8 project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "And Scambos' work is an example of some of the intriguing science that can be done using Landsat 8."

In the longer term, Scambos and his team will try to design weather stations and set them up in the area where the record temperatures occur to confirm the data from Landsat 8 and MODIS. Currently, most of the automated weather stations in the vicinity do not work properly in the dead of winter.

"The research bases there don't have people that stay through the winter to make temperature measurements," Scambos said. "We will need to investigate electronics that can survive those temperatures."

View the NASA animation The Coldest Place in the World: http://www.youtube.com/watch?v=Hp6wMUVb23c

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Grant helps protect critical Hudson River estuarine habitat

June 13, 2013

NOAA's Coastal and Estuarine Land Conservation Program helped protect over 300 acres of critical lands along the Hudson River near the town of Stockport, NY that will be managed by the NYS Department of Environmental Conservation as a protected wildlife habitat, open to the public for passive recreational use.

Download here (Credit: NYS DEC)

A NOAA grant of more than $800,000 has helped New York state complete the acquisition of nearly 300 acres of critical habitat located within the Stockport Creek and Flats biologically important area.

New York’s departments of State and Environmental Conservation and the Scenic Hudson Land Trust, the largest environmental group focused on the Hudson River Valley, joined in the purchase.

The $806,017 grant comes from a fiscal year 2010 grant competition held by NOAA’s Coastal and Estuarine Land Conservation Program (CELCP).

The acquisition will conserve and permanently protect key spawning and nursery habitat for the Hudson River’s migratory fish including blueback herring, alewife, American shad, American eel, striped bass, and the federally endangered short-nosed sturgeon. In addition, 64 acres of globally rare freshwater tidal wetlands will be protected including a segment of land that is part of an important bald eagle habitat corridor.

“This important acquisition will protect vital intertidal marsh and swamp, floodplain forest, and buffer lands which are critical habitat for a host of birds, fish, and other fauna,”said Betsy Blair, manager of the Hudson River reserve. “It will also enable tidal wetlands to migrate landward and upslope with sea level rise, building resilience to climate change in the Hudson River estuary”

“This NOAA conservation grant program is one of America’s best investments because it leverages funds from federal, state and private partners to acquire and protect acres of critical coastal habitat that supports both coastal communities and its ecosystems,” said Margaret Davidson, acting director of NOAA’s Office of Ocean and Coastal Resource Management. “NOAA is pleased to have contributed to the preservation of this important area of the Hudson River valley.”

Map of NOAA's Coastal and Estuarine Land Conservation Program project area along the Hudson River near the town of Stockport, NY.

Download here (Credit: Scenic Hudson.)

This acquisition will protect one of the last major privately owned holdings within the NOAA-funded Hudson River National Estuarine Research Reserve -- a parcel known as the Plotkin property, which will be owned by New York state’s department of environmental conservation (DEC) and managed as a protected wildlife habitat open to the public for passive recreational use.

With the addition of the Plotkin property, the reserve’s Nutten Hook State Unique Area to the north and Hudson River Islands State Park, Gays Point Section to the south, will now be linked to protect almost five miles of contiguous shoreline within the Stockport Flats component of the Hudson River NERR. The property straddles the towns of Stuyvesant and Stockport in Columbia County, N.Y.

“Protecting the ecological values of Little Nutten Hook and Stockport Flats is critical to maintaining and improving Hudson River habitats for numerous fisheries, migratory waterfowl and marsh birds,” said New York DEC Commissioner Joe Martens. “These habitats are important for both the species that depend on them as well as the numerous recreational and economic benefits the Hudson River provides to the people of New York State.”

The Hudson River reserve, one of 28 national estuarine research reserves, is a network of four sites along the Hudson River containing 5,000 acres of estuarine habitat designated in 1982 by NOAA and New York state. The reserve receives funding from NOAA, under the federal Coastal Zone Management Act, and is operated by the DEC as natural field laboratories for research and education, with a strong focus on conserving natural resources, biodiversity, and public access.

NOAA’s CELCP program, established by Congress in 2002 to advance the objectives of the Coastal Zone Management Act, has protected nearly 100,000 acres of critical coastal and estuarine lands in partnership with federal, state, territorial and local government agencies and private organizations.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter and our other social media channels.

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Weather helps Arizona contain huge blaze (AFP)

LOS ANGELES (AFP) – A massive fire in the US state of Arizona has destroyed 27 homes and injured three people, but less powerful winds are helping efforts to contain the blaze, a spokeswoman said Friday.

Some 6,000 people have been ordered to evacuate from two towns in the path of the blaze, which has now consumed some 165,000 hectares (640 square miles), according to the latest update from the firefighters' command center.

More than 3,100 emergency workers are now fighting to douse the flames near the New Mexico border, and the blaze -- the second biggest ever in Arizona -- has now been five percent contained, as opposed to zero percent before Friday.

"We are making progress on suppressing the fire. In the last couple of days the winds have been very favorable," Susan Zornek, a spokeswoman for the Wallow Fire incident command center, told AFP.

Earlier in the week a "red flag" warning was in effect, because of high winds which were fanning the flames.

The towns of Eagar and Springerville were ordered to evacuate Wednesday, while warnings to be prepared to evacuate at short notice have been issued for a handful of other towns including one over the border in New Mexico.

On Thursday a huge DC-10 air tanker which can drop some 13,000 gallons (49,000 liters) of water or retardant at a time was brought in, adding to the 16 helicopters already working to douse the flames.

Some 220 fire engines were tackling the blaze, which started on May 29 and has so far destroyed 27 homes, 24 outbuildings, and is threatening a further 4,000 homes, according to a Friday morning update.

Arizona Governor Jan Brewer on Monday signed a declaration of emergency in response to the wildfires, releasing $200,000 from an emergency response fund.

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