Atacama Desert

The southern Atacama Desert is pictured in this Envisat image, with the border of Chile (west) and Argentina (east) running down the middle. The Atacama is believed to be the driest desert in the world, and the lack of cloud cover in this image highlights the dry climate.

This image was acquired by Envisat’s MERIS instrument on 4 March 2012.

Photo credit: ESA

Note: The Atacama desert is where the various telescopes for the European Southern Observatory are located; it is also where scenes for the James Bond movie, Quantum of Solace, were filmed.

New Estimate of Gross Carbon Emissions From Tropical Deforestation

Distribution of annual carbon emissions from gross forest cover loss between 2000 and 2005 mapped at a spatial resolution of 11.5 miles (18.5 kilometers).

Image credit: Winrock International

Note: For more information, see Study Slashes Deforestation Carbon Emission Estimate.

Picher, Oklahoma

Picher, Oklahoma once boasted 20,000 people in this mining town in northeast Oklahoma. Now, after a 2009 tornado, and a federal cleanup program, the town is a modern-day ghost town. Picher lies in the middle of the Tar Creek Superfund site, an expanse of lead- and zinc-mining towns that extends into Missouri and Kansas. But mine cave-ins, sinkholes, and a creek that flows orange from pollution have forced abandonment of Picher and the surrounding smaller towns. The image was acquired July 12, 2006, covers an area of 17.7 by 16.8 km, and is located at 37 degrees north latitude, 94.8 degrees west longitude.

Photo credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

Lake Garda, Italy

Italy’s Lake Garda and the city of Verona south of the Italian Alps are pictured in this image from ALOS observation satellite. With an area of 370 sq km, Garda is the largest lake in Italy and the third largest in the Alpine region. East of the lake is the Adige River, flowing south before curving east toward Verona. The city of Verona has been awarded World Heritage Site status by UNESCO because of its urban structure and architecture – among them the circular Roman amphitheater, visible when zooming in.

Photo credit: JAXA/ESA

NASA's Aquarius Maps Ocean Salinity Structure

New research using salinity data from NASA's Aquarius instrument on the Aquarius/SAC-D observatory has given scientists an unprecedented look at a key factor involved in the formation of an oceanic wave feature in the tropical Pacific and Atlantic Oceans that influences global climate patterns.

Tropical instability waves are westward-traveling waves that form along the interface between areas of cold and warm sea surface temperatures near the equator. Existing studies suggest that these waves can have wavelengths of 1,000-2,000 kilometers and have an average period between waves of about one month. These waves redistribute various properties of seawater within the ocean, including temperature, salinity, nutrients, and carbon. They interact with ocean currents, affect large-scale climate patterns such as El Niño and La Niña, and influence marine ecosystems and the carbon cycle.

Previous observations of tropical instability waves have been limited to satellite observations of sea surface temperature, sea level, ocean surface wind, and ocean surface chlorophyll abundance, as well as sparse direct ocean measurements. Salinity has been found to play an important role in the physics of these waves, and observations of their salinity are important to understanding them and their impacts on climate variability and prediction, and biogeochemistry. However, until now salinity observations of them have been limited to very sparse direct ocean measurements. Aquarius provides an unprecedented opportunity to observe their salinity.

In a study in press in the journal Geophysical Research Letters, a team led by Tong Lee of NASA's Jet Propulsion Laboratory, Pasadena, California, and including scientists from Earth & Space Research in Seattle, Aquarius data were used to reveal the salinity structure associated with tropical instability waves in the Pacific Ocean. The figure shows sea surface salinity (color shading in panels a and b) on December 18, 2011, derived from Aquarius measurements, showing the peaks and valleys of tropical instability waves in the eastern to central equatorial Pacific Ocean. The salinity structure is coherent with those obtained from other satellite derived products such as sea surface temperature (contour lines in panel a) and ocean surface currents (arrows in panel b). The unit for the sea surface salinity (SSS) is parts per thousand (the Practical Salinity Unit or PSU). The unit for sea surface temperature (SST) is degree centigrade.

The team found that Aquarius' salinity observations showed a clear signature of the waves near the equator in the Pacific Ocean where large contrasts in salinity occur between the saltier waters of the South Pacific and fresher waters of the North Pacific. The Aquarius data reveal that the waves move much faster at the equator than they do away from the equator, a feature that had not previously been well documented.

Aquarius observations show that near the equator, the waves have a dominant period of approximately 17 days. Aquarius' ability to reveal oceanic features on such short timescales was unexpected, as the mission was designed to study salinity changes on time scales of a month and longer. Salinity variability associated with tropical instability waves is larger near the equator, while sea surface temperature and sea level variability associated with the waves is larger a few degrees away from the equator. Salinity observations from Aquarius can therefore fill an important gap in studying tropical instability waves by providing measurements that are complementary to other satellite observations and direct ocean measurements.

Reference: Lee, T.; G. Lagerloef; M. Gierach; H.-Y. Kao; S. Yueh; and K. Dohan, 2012: "Aquarius reveals salinity structure of tropical instability waves," Geophysical Research Letters, in press.

Image credit: NASA/JPL-Caltech/GSFC

The Paraná River

The Paraná River cuts through this image of southern Brazil, acquired by the MERIS instrument on Envisat on 19 March. In the area pictured, the river marks the borders of the Brazilian states of Mato Grosso do Sul to the north and west, São Paulo to the east and Paraná to the south.

Agricultural structures are evident in the surrounding land. Near the center of the image, smoke from a fire was captured blowing southwest from its source.

Photo credit: ESA

A Crack on Pine Island Glacier

This Envisat image shows the Pine Island Glacier in West Antarctica and reveals a crack in the glacier’s tongue about 25 km long. The image was acquired by Envisat’s radar on 6 April 2012, just two days before contact with the satellite was lost.

Photo credit: ESA

Eruption Plume from Sheveluch Volcano

On the night of June 2, 2012, a large eruption plume from eastern Russia's Sheveluch volcano was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft. Sheveluch is one of the most active volcanoes on the Kamchatka peninsula, with frequent explosive events that can disrupt air traffic over the northern Pacific. In this color composite of three thermal infrared channels, the ash component of the plume is depicted in red, the water droplets and ice are in blue, and the sulfur dioxide (SO2) component is in yellow. The image is centered near 56.6 degrees north latitude, 161.4 degrees east longitude, and covers an area of 37 by 74 miles (60 by 120 kilometers).

Image credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

Copenhagen, Denmark

Copenhagen, the capital of Denmark, is highlighted in this image. The largest city in Denmark, Copenhagen is located on the eastern side of the island of Zealand (left) and on the island of Amager (right). The island visible east of Amager is Saltholm, translated as ‘Salt Islet’. The white structure southwest of Saltholm is the artificial island of Peberholm, translated as ‘Pepper Islet’. Peberholm was created as part of the Øresund Bridge, a combined two-track rail and four-lane road bridge-tunnel across the Øresund Strait that connects Copenhagen with the Swedish city of Malmö (not visible). Peberholm serves as a crossover point between the bridge, completed in 2000, and the 4050-m long Drogden Tunnel. Copenhagen Airport is visible as an L-shaped, white structure on the eastern side of Amager.

Photo credit: CNES, Spot Image

Mississippi River Delta

This Landsat image of 3 October 2011 shows the Mississippi River Delta, where the largest river in the United States empties into the Gulf of Mexico. In this false-color image, land vegetation appears pink, while the sediment in the surrounding waters are bright blue and green.

Photo credit: USGS/ESA

Yarlung Zangpo Grand Canyon, Tibet

The Yarlung Zangpo Grand Canyon (or Tsangpo Gorge) in Tibet is the deepest canyon in the world, and longer than the Grand Canyon. As the river passes between the peaks of Namcha Barwa (7,782 m) and Gyala Peri (7,234 m) it reaches a maximum depth of 6,009 m. In 2002, seven kayakers were the first westerners to navigate the entire gorge. The image was acquired February 25, 2004, and is located near 29.7 degrees north latitude, 95 degrees east longitude.

Photo credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

Ground Deformation at the Nea Kameni Volcano

Evolution of ground deformation over Nea Kameni Volcano (Santorini, Greece) from March 2011 to February 2012. The animation was derived using data from Differential Interferometric Synthetic Aperture Radar analysis of Envisat’s radar data.

Video credit: ESA

Note: This particular island is famous for the volcanic eruption that destroyed the Minoan civilization living on the island of Thera, as Santorini was known at the time. The artwork that was preserved by the eruption is very beautiful.

Texas Wildfires

The Livermore and Spring Ranch fires near the Davis Mountains Resort, Texas, burned 13,000 and 11,000 acres respectively. The fires started on April 21, 2012, by dry lightning. By May 12, when this image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft was acquired, both fires were contained, and management had been turned over to local authorities. The image shows healthy vegetation in red, burned areas in black, and bare ground in blue-gray and yellow-tan. The image covers an area of 13.6 by 17.8 miles (22 by 28.5 kilometers) and is located at 30.7 degrees north latitude, 104.2 degrees west longitude.

Photo credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

Three Gorges Dam, China

The Three Gorges Dam spans the Yangtze River in east-central China, and is the world's largest power station in terms of installed capacity, with its vast reservoir stretching for 660 km. Since its completion in 2008, over 1.3 million people were relocated; 13 cities, 140 towns, and 1350 villages were submerged; and the cost of the project exceeded $40 billion. According to the BBC News, landslides and bank collapses upriver from the dam may force authorities to move another 100,000 people. The image was acquired June 24, 2009, and is located at 30.8 degrees north latitude, 111 degrees east longitude.

Photo credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

Hot Spots in Northern France

This animation shows two images of northern France acquired by two different instruments on the Envisat satellite: MERIS and the Advanced Along-Track Scanning Radiometer.

The first image, acquired on 20 February 2012, shows Paris in the center. The river flowing through the city and into the English Channel is the Seine. East of Paris, vineyards and fields of the famous Champagne-Ardenne region appear lighter in color. The second radiometer image, acquired on 23 May 2011, shows heat, with yellows and reds depicting higher temperatures compared to the cooler blue areas. In this image, urban areas south of Paris – such as Orléans – stand out.

Video credit: ESA; text credit: ESA

Gulf of Fonseca, Honduras

The eastern end of the Gulf of Fonseca, in Honduras, was originally the site of extensive wetlands ecosystem, dominated by six species of mangroves. In 1986 (right image), the Landsat Thematic Mapper shows an environment minimally impacted by human activities. By 2009, when the ASTER image was acquired (left), hundreds of square kilometers of coastal swamps had been converted to shrimp ponds, appearing as blue rectangles near the water line. The images cover an area of 30 x 36 km, and are located at 13 degrees north latitude, 87.2 degrees west longitude.

Photo credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

Popocatepetl Volcano

Mexico's active Popocatepetl volcano, located about 40 miles southeast of Mexico City, has been spewing water vapor, gas, ashes and glowing rocks since its most recent eruption period began in April 2012. Civil defense authorities have set up evacuation shelters should they become necessary. In 2000, eruptions of the nearly 18,000-foot-high (5,400 meter) volcano led to the evacuation of tens of thousands of residents. More than 30 million people live within sight of the mountain.

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft acquired these two images on April 23, 2012. The left image is in simulated natural color; the right image combines three thermal infrared channels, displaying the eruption plume in purple and pink, blowing toward the northeast. A small hotspot can be seen in the summit crater. The image covers an area of 19.2 by 27.6 miles (30 by 44.5 kilometers) and is located at 19 degrees north latitude, 98.6 degrees west longitude.

Photo credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

Moskva at Night

Moscow appears at the center of this nighttime image photographed by the Expedition 30 crew aboard the International Space Station, flying at an altitude of approximately 240 miles on March 28, 2012. A solar array panel for the space station is on the left side of the frame. The view is to the north-northwest from a nadir of approximately 49.4 degrees north latitude and 42.1 degrees east longitude, about 100 miles west-northwest of Volgograd. The Aurora Borealis, airglow and daybreak frame the horizon.

Photo credit: NASA

Shadow of a Solar Eclipse

The International Space Station (ISS) was in position to view the umbral (ground) shadow cast by the Moon as it moved between Earth and the Sun during a solar eclipse on March 29, 2006. This astronaut image captures the umbral shadow across southern Turkey, northern Cyprus and the Mediterranean Sea.

Photo credit: NASA

Portugal and Spain

Envisat’s Medium Resolution Imaging Spectrometer (MERIS) captured this image on 8 April 2012 at 13:05 CEST. The image was transmitted in Ka-band to ESA/ESRIN though direct transmission via Artemis, the ESA Data Relay satellite. The image, which is of nominal quality, shows Portugal and Spain. It is the last Envisat data transmitted via Ka-band before the communication anomaly affected the Envisat satellite.

Photo credit: ESA