Hurricane Amanda

Amanda, the first named storm of the 2014 hurricane season in the Americas, is seen off the west coast of Mexico in an image acquired on May 25 by the Moderate Resolution Imaging Spectrometer (MODIS) on NASA's Aqua satellite. At the time of the image, Amanda was a category 4 hurricane. Amanda's winds peaked at 155 miles (250 kilometers) per hour, making it the strongest May hurricane on record in the eastern Pacific. In the image, Hurricane Amanda sports a distinct eye as well as heavy rain bands wound tightly around the center.

Image credit: NASA/GFSC

The Coldest Place on Earth

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.

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, Colorado, joined a team of researchers reporting the findings Monday at the American Geophysical Union meeting in San Francisco.

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 August 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.

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."

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, Maryland. Since its launch February 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."

Image credit: Ted Scambos, National Snow and Ice Data Center; text credit: NASA

Totten Glacier Ice Shelf

This image shows the Totten Glacier ice shelf in East Antarctica (the wrinkled white area at top left) on September 25, 2013. Two large open-water polynyas appear on the sea ice below and to the right of the shelf, as well as several smaller ones. The open-water areas are bright black. The stippled diagonal line from lower left to upper right is the outer edge of the sea ice, with cloud cover to the right of that line. The image is from the Moderate Resolution Imaging Spectroradiometer instrument on NASA's Aqua satellite.

Photo credit: NASA

Note: For more information, see NASA Finds Reducing Salt Is Bad for Glacial Health.

Dasht-e Lut Salt Desert

The Dasht-e Lut salt desert in southeast Iran is captured in this Envisat image.

The desert is often called the ‘hottest place on Earth’ as satellites measured record surface temperatures there for several years. The highest land surface temperature ever recorded was in the Lut Desert in 2005 at 70.7ºC, as measured by NASA’s Aqua satellite.

The light area in the center of the image are the long, parallel wind-carved ridges and furrows. The darker area to the east is an extent of massive sand dunes, some reaching up to 300 m tall.

In the upper-right section we can see a light green, shallow body of water that straddles Iran’s border with Afghanistan. With their arid surroundings, the wetlands in this border region have been a major source of food and fresh water for thousands of years, as well as an important stop for migratory birds. But irrigation expansion combined with droughts have caused the water levels in these wetlands to drop significantly – and some years even dry up.

In the lower-left we can see the white, snow-capped Jebal Barez mountains.

A major earthquake struck about 100 km east of the snow-caps in 2003, its epicenter near the ancient city of Bam (lower-central portion of image). Iran experiences frequent tectonic activity as several major fault lines cross the country.

This image was acquired by Envisat’s MERIS instrument on 2 April 2012 and is also featured on the Earth from Space video program.

Photo credit: ESA

The Spread of Western Wildfire Pollution

A new movie produced with data from the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft shows the spread of carbon monoxide pollution across North America from fires in the Western U.S., including the Beaver Creek Fire in Idaho and the Rim Fire in California. The movie shows carbon monoxide concentrations at altitude 18,000 feet (5.5 kilometers) as measured by AIRS.

About AIRS
The Atmospheric Infrared Sounder, AIRS, in conjunction with the Advanced Microwave Sounding Unit, AMSU, senses emitted infrared and microwave radiation from Earth to provide a three-dimensional look at Earth's weather and climate. Working in tandem, the two instruments make simultaneous observations all the way down to Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, three-dimensional map of atmospheric temperature and humidity, cloud amounts and heights, greenhouse gas concentrations, and many other atmospheric phenomena. Launched into Earth orbit in 2002, the AIRS and AMSU instruments fly onboard NASA's Aqua spacecraft and are managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

Video credit: NASA/JPL-Caltech

Rates of Basal Melt of Antarctic Ice Shelves

Rates of basal melt of Antarctic ice shelves (melting of the shelves from underneath) overlaid on a 2009 mosaic of Antarctica created from data from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Terra and Aqua spacecraft. Red shades denote melt rates of less than 5 meters (16.4 feet) per year (freezing conditions), while blue shades represent melt rates of greater than 5 meters (16.4 feet) per year (melting conditions). The perimeters of the ice shelves in 2007-2008, excluding ice rises and ice islands, are shown by thin black lines. Each circular graph is proportional in area to the total ice mass loss measured from each ice shelf, in gigatons per year, with the proportion of ice lost due to the calving of icebergs denoted by hatched lines and the proportion due to basal melting denoted in black.

Image credit: NASA/JPL-Caltech/UC Irvine/Columbia University

Note: For more information, see Warm Ocean Causing Most Antarctic Ice Shelf Mass Loss

Petermann Glacier

The Petermann Glacier grinds and slides toward the sea along the northwestern coast of Greenland, terminating in a giant floating ice tongue. Like other glaciers that end in the ocean, Petermann periodically calves icebergs. A massive iceberg, or ice island, broke off of the Petermann Glacier in 2010. Now, nearly two years later, another chunk of ice has broken free.

The Moderate Resolution Imaging Spectroradiometer, or MODIS, on NASA’s Aqua satellite observed the new iceberg calving and drifting downstream on July 16–17, 2012. Because Aqua is a polar-orbiting satellite, it makes multiple passes over the polar regions each day.

Photo credit: NASA