http://www.redorbit.com/images/1/images-of-the-day/gallery/1/earth-4 http://www.redorbit.com/media/themes/redorbit/images/logo_160x80.gif http://www.redorbit.com/ 160 80 http://www.redorbit.com/media/gallery/earth/iod-earth-052312.jpg 2012-05-23 11:31:09
Credit: NASA]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-052212.jpg 2012-05-22 11:12:51
Although Alberto sported the spiral shape typical of tropical storms, it lacked a distinct eye, and had not reached hurricane strength. Storm clouds did, however, extend far inland over the Carolinas. As of 5 p.m. Eastern Daylight Time (EDT) May 19, the storm packed maximum sustained winds of 45 miles (75 kilometers) per hour. An update issued later that evening indicated wind speeds of 60 miles (95 kilometers) per hour, and wind speeds were at 50 miles (85 kilometers) per hour the next morning. As of 5 p.m. EDT May 20, the NHC discontinued the tropical storm watch along the U.S. East Coast.

NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center. Caption by Michon Scott.]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-052112.jpg 2012-05-21 11:19:17
At the far northern edge of this image lies Canada. Below the border eleven states have been outlined. From north to south, starting at the left edge of the image the states are: North Dakota, Minnesota, Wisconsin, Michigan; South Dakota; Nebraska, Iowa, Illinois, Ohio; and northern Kansas and Missouri. Lake Superior lies near the upper right corner and Lake Superior to the southeast. The Mississippi River forms the border between several states as it courses from Lake Itasca in Minnesota to the Gulf of Mexico, far south of this image. To the west the Missouri River courses through the Dakotas and across Missouri until it joins the Mississippi in St. Louis, Missouri.

The entire region is swathed in an fine smoke, as evidenced by the hazy appearance to the image, which seems thickest over the Mississippi River Valley. According to the U.S. Air Quality Smog Blog, created by the University of Maryland, Baltimore County, smoke that showed up over the central United States on May 14 was tracked back to wildfires along the Russian/China border near Manchuria. The plume of Siberian smoke was lofted to high altitudes by a serious of pyrocumulonibus clouds, which are cumulus clouds that form over powerful heat sources, such as large wildfires. Once aloft, smoke can be carried extensive distances.

As of May 18, the air quality index (AQI) in much of the Upper Midwest was reported to be Code Yellow (Moderate) and reached Code Orange (Unhealthy for Sensitive Groups) along part of the Mississippi River Valley. A relatively quiet weather pattern, with weak winds in the mid and upper troposphere are limiting the advancement of the smoke layer. The Navy Aerosol Analysis and Prediction System (NAAPS) are forecasting the smoke to remain nearly stationary through at least May 20.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-052012.jpg 2012-05-20 11:32:28
The image was taken by Russia\'s Electro-L satellite, and unlike other images taken by spacecrafts, it was taken in one single shot.

Normally, several images are taken by a space agency, then are stitched together in order to create one big image. However, Roscosmos went about it another way with its 121 megapixel photo. Each pixel in the image represents a little over a half-mile of the Earth\'s surface.

The Electro-L satellite captures a picture of this quality every half-hour to monitor the weather on Earth. If a strange weather pattern is seen, the Russian operators can remotely command the satellite to take images every 10 minutes.

The image uses a combination of visible and near-infrared wavelengths to make-up the image, so vegetation is seen as red, rather than green.

The Russian satellite, which launched in January 2011, sits in an orbit that matches the Earth\'s rotation, known as a geo-stationary orbit, so that it remains on a fixed point of the planet.

Credit: Electro-L]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-051912.jpg 2012-05-19 12:09:09
This natural-color image captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite shows the eastern half of the Black Sea on May 18, 2012. Milky, light blue and turquoise-colored water in the middle of the sea is likely rich with blooming phytoplankton that trace the flow of water currents. Closer to the coast, the colors include more brown and green, perhaps a brew of sediment and organic matter washing out from rivers and streams, though it may also be a sign of phytoplankton. Puffs of spring clouds linger over parts of the coastline.

Phytoplankton are the “primary producers” of the seas and oceans. These plant-like, microscopic algae, bacteria, and protists use chlorophyll to make their own food from sunlight and dissolved nutrients. More than 150 different types of phytoplankton have been observed in the Black Sea over the years, and they have supported a rich bounty of fish and other marine organisms.

With scores of cities, resorts, and villages on its shores (many for thousands of years), and with waterways carrying farm runoff and wastewater from the interior of Europe and western Asia, the Black Sea is often teeming with phytoplankton. The layered structure of the water column also promotes plankton growth, as lighter, fresher water from the rivers gets concentrated on top and does not mix with the denser, saltier water coming in from the Mediterranean and Marmara Seas.

Scientists and resource managers have been working in recent years to stem the flow of nutrients and restore water quality, which can suffer due to an overabundance of phytoplankton. Extreme and persistent blooms can suck most of the oxygen out of the water—a process known as eutrophication—and suffocate other marine life. Predominance by certain phytoplankton species can also crowd out others that give the sea its diversity of plant and fish life.

NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response. Caption by Michael Carlowicz.]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-051812.jpg 2012-05-18 11:04:44
According to Zeenews.com, on May 17 Russian officials announced that twenty one forest fires were burning on a total of over 3,000 hectares, with 2,600 hectares blazing in Buryatia and almost 500 hectares in Khabarovsk territory. Three new fires were seen in Tunkinsky National Park in the past 24 hours alone. In Buryatia, over 400 forest fires have burned more than 30,000 hectares of forest since the beginning of spring this year.

The red “hotspots” seen in the image mark areas where the MODIS instrument has detected thermal anomalies, or places where the temperature is higher than the background. Combined with smoke, these thermal anomalies are strong indicators of fire.

The fires are numerous, but the smoke is extremely heavy throughout the region. Fires may produce large amounts of smoke when they burn moist fuel. It can be speculated that the melting of the thick winter snows has moistened the leaf litter on the ground. The high temperatures of the large wildfires may have ignited the damp organic matter lying on the forest floor, creating copious amounts of smoke as they burn as ground fires. Whatever the cause of the heavy smoke, the entire region lies under a gray veil, and smoke has been seen as far north as the Bering Sea.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-051712.jpg 2012-05-17 11:09:21
Canada lies at the top of the image, and seven states can be seen south of the Canada-United States border. Washington, Idaho and Montana form the top row, from west to east. Oregon lies south of Washington. The final row is comprised of California, Nevada and Utah.

Snow lies atop the mountain peaks in the northern states and in California. In the arid interior states, particularly Nevada and Utah, the white splotches mark salt pans – natural depressions that once held salty water and have since dried out, leaving highly reflective expanses of salt on the surface of the tan land. The Great Salt Lake can be seen in northern Utah. It is a highly salty body of water and the largest saltwater lake in the Western Hemisphere. Bonneville Flats lies to the west of lake in northwestern Utah.

On May 13, Accuweather.com described the weather across the Pacific Northwest as a “summer preview”. An offshore wind blew air across the warm interior and out to the ocean, keeping the cooling ocean air at bay and causing warming conditions. In fact, the sunny skies and offshore wind set up a potential for near-record warm temperatures for several days. Further south, in California, the winds were blowing onshore, causing cooler temperatures with potential for the formation of fog.

The warm temperatures and sunny skies of the Pacific Northwest were not expected to last, however. A weak cold front is predicted to move into the area by May 15, turning winds onshore and bringing cooler temperatures. This front may also spark thunderstorms with little accompanying rainfall in Oregon and California, increasing the risk of wildfires.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-051612.jpg 2012-05-16 10:53:42
The smoke may have arisen from wildfires in the region around Lake Baikal, where numerous wildfires burned in early May. A model from the NOAA Air Resources Laboratory suggests that smoke from the Lake Baikal region would take just a few days to reach the Bering Sea.

In a study published in 2004, scientists tracked the movement of smoke from Russian wildfires, finding that it typically travels in one of two directions: northwest towards Scandinavia or east toward the Okhotsk Sea. The smoke blowing east often crosses the Bering Sea towards Alaska and Canada.

Smoke from the Lake Baikal region also appeared to be hampering air quality over China, as shown in this image.

NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response. Caption by Michon Scott with information from Ralph Kahn, NASA Goddard Space Flight Center.]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-051512.jpg 2012-05-15 11:09:13
NASA Earth Observatory image by Jesse Allen and Robert Simmon, with EO-1 ALI data from the NASA EO-1 team. Caption by Robert Simmon.]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-051412.jpg 2012-05-14 10:58:06
Other smaller lakes hold red and brown water, a result of the interplay of water depth and resident organisms such as algae. The algae color varies depending on water temperature and salinity. (A similar process is observed in pink and red floodwaters when they pond in Lake Eyre, a mostly dry lake in Australia. In Lake Eyre, researchers know that the color is indeed due to algae growth.)

Typically, little water or sediment reaches the floor of the Etosha Pan because the water seeps into the riverbeds along their courses. The floor of the pan itself is only rarely covered by even a thin sheet of water. In this image, there was enough surface flow to reach the pan, but too little to flow beyond the inlet bay. A prior flood event, when water entered the pan via the Oshigambo River, was documented in astronaut imagery in 2006.

The straight line that crosses the image is the northern fence line of Namibia’s Etosha National Park. This three-meter-high fence keeps wildlife from crossing into the numerous small farms of the relatively densely populated Owambo region of Namibia, north of the pan. The large Etosha lakebed (120 kilometers long, or 75 miles) is at the center of Namibia’s largest wildlife park and a major tourist attraction.

Astronaut photograph ISS030-E-234965 was acquired on December 30, 2011, with a Nikon D2Xs digital camera using a 180 mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 30 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by M. Justin Wilkinson, Jacobs/ESCG at NASA-JSC. ]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-051312.jpg 2012-05-13 11:06:14
This natural-color image of Pagan Island from May 7, 2012, was collected by the MODIS instrument on the Terra satellite. A volcanic plume blows westward from the summit of North Pagan Volcano. The plume’s blue tint suggests the presence of sulfur dioxide. Several hours after this image was acquired, the Ozone Monitoring Instrument (OMI) on the Aura satellite detected elevated levels of sulfur dioxide just west of the volcano.

Pagan Island is located in the arc of the islands which make up the Commonwealth of the Northern Mariana Islands (CNMI). The island contains two straovolcanoes which are connected by a narrow isthmus. Saipan, capital city, is located 173 nautical miles south of Pagan Island.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-051212.jpg 2012-05-12 11:23:29
The rugged, mountainous arc of Graham Land, the northernmost tip of the Antarctic Peninsula, can be found in the lower right corner of the image, stretching northeast to the center of the image. The Southern Ocean, which appears inky black, lies to the north and west of Graham Land. Clouds cover the ocean and in some places the clouds are aligned in parallel streets, especially where the wind blows over ice-covered islands west of the mainland.

The northernmost edge of the Larson Ice Shelf hugs the Peninsula in the lower left corner of the image, and appears bright blue-white. At the edge of the ice shelf, cracks and ripples appear in the fast ice covering the sea. In the lower right section of the image, bright white clouds cast gray shadows over the sea ice.

Although the recent weeks have been warm, the summer has not been abnormally hot. Clear evidence of this is seen in the fast ice, which remains relatively intact at the end of the warm season. April is fall in the southern hemisphere, and cooling will soon cause the fast ice to thicken once again as the frigid winter sets in.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-051112.jpg 2012-05-11 11:17:24
The image above, captured on May 4, 2012, by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA’s Aqua satellite, shows ice breaking up in the central part of the lake. Ice remains throughout the northern portion, but drifting ice and large patches of open water are visible throughout the southern part. (Ice often lasts longer in the extreme southeastern part of Lake Baikal because that area is shallow.)

The image also shows fast ice along the coasts. Fast ice is anchored, or fastened, to the shore and does not move with the winds or currents. It usually persists longer than ice that forms over deeper water.

People living along the lake have long kept track of the freezing and break-up. One of the best records comes from a monitoring station at Listvyanka, a village on the southeastern coast of the lake that’s about 70 kilometers (40 miles) southeast of Irkutsk. The Listvyanka station has kept uninterrupted records of ice formation and melting that date back to 1869.

Measurements from Listvyanka reveal some interesting trends related to the timing of ice break-up; most notably that it is occurring earlier now than in the past. In the 1870s, thawing began around May 10; today, it often begins in late April. One study by a Swiss researcher calculated that the thawing date had moved by half a day per decade between 1869 and 1999. However, the most rapid change (about 3 days earlier per decade) occurred between 1869 and 1920. Since 1920, the date of ice breakup has remained fairly constant at Listvynaka. Ice formation, however, has occurred later in the winter, so the overall ice cover doesn\'t last as long as it once did.

But what happens at Listvyanka doesn\'t necessarily apply to the rest of Lake Baikal, so researchers have turned to satellites for a broader view. A team led by Alexei Kouraev, a scientist based in St. Petersburg, has mined the data collected by altimeters on six different satellites (including NASA\'s Jason-1 satellite and Europe’s EnviSat satellite) to produce records of thawing between 1992 and 2004.

The study has shown that over the central and northern part of the lake, ice has been forming later, breaking up later, and lasting longer overall since 1992. (For the southern part of Lake Baikal, the satellites show the timing of the breakup has been fairly constant, but that ice is forming later in the winter, which is consistent with the Listvyanka record.

The reasons for the change are still to be sorted out. Air temperatures have a leading role in how long ice lasts, and recent decades have seen Siberian winters grow colder due to the behavior of the Arctic Oscillation. Kouraev\'s team also lists a number of other factors that can affect how long Baikal’s ice lasts, including wind patterns, lake currents, clouds, snowfall amount, and the volume of river water discharged into the lake.

NASA image by Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response. Caption by Adam Voiland.]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-051012.jpg 2012-05-10 11:16:46
Researchers have known for years that large amounts of methane are frozen in Arctic tundra soils and in marine sediments (including gas hydrates). But now a multi-institutional study led by Eric Kort—now at NASA’s Jet Propulsion Laboratory after conducting the research at Harvard University—has uncovered a surprising and potentially important source of methane: the Arctic Ocean itself.

The photograph above was taken by Kort, and it shows leads and cracks in the ice cover of the Arctic Ocean north of Alaska. During five research flights in 2009–10, Kort and colleagues measured increased methane levels while flying at low altitudes north of the Chukchi and Beaufort Seas in a National Science Foundation/National Center for Atmospheric Research (NCAR) Gulfstream V aircraft as part of the HIAPER Pole-to-Pole Observations (HIPPO) airborne campaign.

The methane level detected during the flights was about one-half percent higher than normal background levels.
 But where was the methane coming from? The team detected no excess carbon monoxide in the atmosphere, which would have been a signature of methane coming from the human combustion of fuels. And based on the time of year, the location, and the nature of the emissions, it was unlikely that the methane was coming from high-latitude wetlands or geologic reservoirs.

By comparing the locations of the enhanced methane levels with airborne measurements of carbon monoxide, water vapor, and ozone, the researchers from six institutions pinpointed a source: the ocean surface, in places where there were cracks and openings in the sea ice cover. The cracks were allowing methane in the top layers of the sea to escape into the atmosphere. The team did not detect enhanced methane levels over areas of solid ice.

Kort noted that previous studies had detected high concentrations of methane in Arctic surface waters, but no one had predicted that this dissolved methane would find its way into the overlying atmosphere. Scientists are not yet sure how the methane is produced, but Kort suspects biological productivity in Arctic surface waters may be the culprit.

“While the methane levels we detected weren\'t particularly large, the potential source region, the Arctic Ocean, is vast,” he said. “Our finding could represent a noticeable new global source of methane.”


References

Kort, E.A., et al (2012) Atmospheric observations of Arctic Ocean methane emissions up to 82° north. Nature Geoscience 5, 318–321.

Courtesy Eric Kort, Jet Propulsion Laboratory. Caption based on a text by Alan Buis, JPL. The research was funded by the National Science Foundation, with additional support from the National Center for Atmospheric Research, NASA, and the National Oceanic and Atmospheric Administration. ]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-050912.jpg 2012-05-09 11:19:58
The Moderate Resolution Imaging Spectroradiometer (MODIS) flying aboard NASA’s Terra’s satellite captured this true-color image on May 2, 2012, four days after the dust storm began. In this image, the dust can be seen to be thinning and dispersing, compared to earlier images.

Most of the dust appears to be blowing across Mauritania (north) and Senegal (south). The coastal countries south of Senegal, The Gambia, Guinea-Bissau, and Guinea, are also covered by the curling band of dust. In the Atlantic Ocean, the Cape Verde Islands remain shrouded by a thick veil of tan dust. The north-east to south-west movement of the prevailing wind is written in both the dust and clouds near Cape Verde. Not only does the dust plume leave a trail in the sky, but cloud vortices can be seen on the leeward side of the islands.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-050812.jpg 2012-05-08 11:14:47
Credit: Illustration by Jack Cook, Woods Hole Oceanographic Institution; USGS.

Data source: Igor Shiklomanov\'s chapter \"World fresh water resources\" in Peter H. Gleick (editor), 1993, Water in Crisis: A Guide to the World\'s Fresh Water Resources (Oxford University Press, New York).]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-050712.jpg 2012-05-07 10:57:35
Originally called Tindouf, the 3.5-kilometer wide crater (image center) has been heavily eroded since its formation; however, its circular morphology is highlighted by exposures of older sedimentary rock layers that form roughly northwest to southeast-trending ridgelines. From the vantage point of an astronaut on the International Space Station, the impact crater is clearly visible with a magnifying camera lens.

A geologist interpreting this image to build a geological history of the region would conclude that the Ouarkziz crater is younger than the sedimentary rocks, as the rock layers had to be already present for the meteor to hit them. Likewise, a stream channel is visible cutting across the center of the structure, indicating that the channel formed after the impact had occurred. This Principal of Cross-Cutting Relationships, usually attributed to the 19th century geologist Charles Lyell, is a basic logic tool used by geologists to build relative sequence and history of events when investigating a region.

Astronaut photograph ISS030-E-254011 was acquired on April 21, 2012, with a Nikon D3X digital camera using a 400 mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 30 crew.

Caption by William L. Stefanov, Jacobs/ESCG at NASA-JSC.]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-050612.jpg 2012-05-06 13:45:47
At times, however, the furious mood calms, the clouds part, and sunshine warms the frigid archipelago. On April 28, 2012, the Moderate Resolution Imaging Spectroradiometer aboard the Terra satellite passed over the Southern Ocean and captured this nearly cloud-free glimpse of the South Sandwich Islands.

The South Sandwich Islands consists of a chain of eleven main islands that bend in an arc about 240-miles (390 kilometers) long. They are volcanic in origin, and, with an age of less than 5 million years, are considered young. Many of the islands, which arise from the subduction of the South American Plate beneath the South Sandwich Plate, are still volcanically active. From May until November, the islands are generally surrounded by pack ice; they remain covered by ice and snow year-round.

Despite the stormy winds, ever changing clouds, rumbling volcanoes, and frigid cover of ice and snow, the South Sandwich Islands teem with life. In 1997, two surveys designed to identify and estimate the species found on the Islands found 16 species of breeding birds, including globally significant numbers of chinstrap penguins, Antarctic fulmars, cape petrels and snow petrels, and five species of seal inhabiting the islands. The number of the chinstrap penguins represents about 30% of the world population, but this survey estimated a significantly lower number of these birds than previously estimated. Other than the wildlife, visitors to these islands are rare. There are no human settlements on the South Sandwich Islands.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-050512.jpg 2012-05-05 13:34:24
The bloom indicates mineral-rich waters from the mixing of surface waters with deeper waters. Phytoplankton depend on these minerals, making blooms like this common in the spring and summer.

These microscopic organisms are the basis of the marine food chain, and play an important role in removing carbon dioxide from the atmosphere and producing oxygen in the oceans. By helping to regulate the carbon cycle, phytoplankton are important to the global climate system.

Since the phytoplankton are sensitive to environmental changes, it is important to monitor and model them for climate change calculations and to identify potentially harmful blooms.

In the lower-right corner, we can see part of County Mayo’s coast, in northwest Ireland – which appears pink in the false-color image.

Broadhaven Bay, with its opening facing north, is visible. This important marine habitat is frequented by the bottlenose dolphin, the harbor porpoise, the grey and common seals, and the European otter.

This SPOT-5 image was acquired on 2 June 2006 with a spatial resolution of 10 m.

The satellite is supported by ESA as a Third Party Mission, which means ESA uses its multi-mission European ground infrastructure and expertise to acquire, process and distribute data from the satellite to its wide user community.

SPOT-5 was built by France’s space agency, CNES, and its imagery is distributed commercially by Spot Image.

Credits: CNES/Spot Image/ESA]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-050412.jpg 2012-05-04 11:16:17
Image Credit: NASA]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-050312.jpg 2012-05-03 11:15:58
The flights are part of a six-year mission called IceBridge. The airborne campaign allows scientists to keep an eye on the complex dynamics of the ice, helping them project how much melting ice sheets might elevate sea level and how fast sea ice is likely to retreat. Funded and structured like a satellite mission, IceBridge continues measurements started by the Ice, Cloud, and Land Elevation Satellite (ICESat) in 2003. ICESat stopped collecting data in 2009, making IceBridge critical for ensuring a continuous series of observations until ICESat-2 launches in 2016. IceBridge flights also collect data useful for climate modeling that ICESat could not, including measures of the land topography beneath the ice, grounding line position, and ice and snow thickness.

The top image, captured during an IceBridge flight, shows a glacier in eastern Greenland flowing through a long and narrow valley—a fjord—carved by the movement of ice. Where the edge of the glacier meets the sea, there’s a layer of floating ice dimpled with chunks of icebergs that have broken off from the glacier. Understanding ice mélanges, as these conglomerations are called, is important because there is evidence that they can slow the rate that glaciers like this slip into the sea. The photograph was taken with a camera aboard NASA’s P-3B aircraft on April 25, 2012.

The image below shows a closer view of a different ice mélange; the blue patch in the middle of the image is possibly the result of turbulence from a recent calving event. Because of the disturbance, the ice appears to be thinner and more transparent to the water below. In addition, the underside of ice from glaciers often has a blue color, so it’s not unusual for ice that recently broke off from a glacier to appear this color. This photograph, also captured during a P-3B flight, was taken on April 14.

This year’s Arctic campaign stands out for completing several more sea ice flights than in previous years and for covering a greater distance. Another highlight: the IceBridge team recently flew a set of coordinated flights with European Space Agency aircraft in order to verify ice thickness measurements made by CryoSat-2.

Throughout the campaign, scientists in the field have been sending back dispatches via the mission’s blog. “The once seemingly insignificant and remote Arctic region is now understood to be intimately connected to the rest of the planet,” noted Goddard Space Flight Center’s Nathan Kurtz in a post published on March 27. “Sea ice variability affecting the severity of snow storms in Europe, melting sea ice increasing the absorption of sunlight by the Earth, and melting ice sheets causing sea level rise are but a few of many such connections.“

NASA images from the IceBridge Science Team and taken by Jefferson Beck and Maria-José Viñas. Image interpretation by Bob Bindschadler and Sophie Nowicki. Caption by Adam Voiland with reporting from George Hale and Holli Riebeek.]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-050212.jpg 2012-05-02 11:32:23
In this mid-spring image, captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite on April 24, 2012, the boreal forests in Denali National Park appear the darkest green, and nearly snow free, near the center of the image, while clouds cover some of the peaks in the 600-mile-long Alaska Range that stretches across the region. On April 20, the Denali National Park and Preserve Superintendent announced that, due to longer days and warming temperatures, the snow cover was no longer adequate for the use of snowmobiles north of the Alaska Range.

Across much of the inland region, the greenish-gray coloration suggests that vegetation is beginning to be seen through a thinning snow cover. In contrast the tundra of the coastal regions, as well as some of the rugged high terrain, remains bright white due to a blanket of snow, as does Nunivak Island.

Sea ice has begun to melt and pull away from the coastline, and the deep blue waters of the Bering Sea and Bristol Bay are clearly visible peeking between the ice and the coast. Large chunks of ice float in the Bering Sea northwest of Nunivak, while thinner ice floats in lacy, graceful swirls, particularly in the more southerly Bristol Bay.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-050112.jpg 2012-05-01 11:09:10
The natural-color image above from DigitalGlobe’s Worldview-2 satellite shows a section of Queens, New York, on September 15, 2010. Viewed from space, the city is a patchwork of dark (often black) surfaces, along with white and other colored rooftops. The plot below the image, based on data from researchers at Columbia University and the NASA Goddard Institute for Space Studies, shows the surface or “skin” temperature of different-colored rooftops in early August 2010.

“I see surface temperatures in the city that routinely exceed what you might find in the desert,” says Stuart Gaffin, who studies the urban heat island effect, the propensity of cities to trap heat and grow considerably warmer than the surrounding natural environment. Heat islands are caused by the construction of dark surfaces—like asphalt pavement and tar-paper roofs—and the removal of vegetation—which cools the land with both shade and moisture. According to the U.S. Environmental Protection Agency, urban areas regularly record air temperatures as much as 6° Celsius (10° Fahrenheit) hotter than the surrounding suburban and rural areas.

Using portable infrared radiometers, Gaffin and colleagues have been measuring land-skin temperatures (LSTs) in greater New York City, including at the Con Edison (power company) buildings shown above. They have observed temperatures as high as 77 to 82°C (170 to 180°F) on the black rooftops of the city in mid-summer. Those hot roofs amplify the oppressiveness of summer by radiating extra heat both by day and at night. Even in winter, rooftop temperatures can be tens of degrees warmer than local air temperatures.

Gaffin and others are interested in how rooftops and other flat, impervious surfaces can concentrate heat, and in how they can be made to reflect more. They have been working for nearly a decade to find creative solutions to reduce heat island effects in cities, such as resurfacing rooftops with white paint or with low-maintenance, lightweight vegetation.
In a recent study, Gaffin and colleagues compared the surface temperature of black, white, and “green” (vegetated) roofs and found that black roofs can be up to 30°C (54°F) hotter than a green or white roof. Installing a plant-covered roof is the ultimate technique to combat urban heat because it adds a combination of slight shading and a lot of cooling moisture.

But the researchers found that even a simple step like painting black roofs white—increasing the albedo, or reflection of light—can reduce temperatures dramatically. In a program partly sponsored by the New York City government, white synthetic surfaces and paints were found to reduce peak rooftop temperatures by 24°C (43°F) compared to typical black rooftops.

“Cities have been progressively darkening the landscape for hundreds of years,” said Gaffin. “City roofs are traditionally black because asphalt and tar are waterproof, tough, ductile and were easiest to apply to complex rooftop geometries. But from a climate and urban heat island standpoint, it makes a lot of sense to install bright, white roofs. That\'s why we say, ‘Bright is the new black.’”

Images by Robert Simmon, using data ©2010 DigitalGlobe (image) and from the Columbia University Center for Climate Systems Research (graph). Caption by Mike Carlowicz, with reporting from Patrick Lynch, NASA Earth Science News Team.]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-043012.jpg 2012-04-30 11:17:27
The island is volcanic in origin and has a summit elevation of 775 meters (2,543 feet) above sea level. The Île aux Cochons stratovolcano is thought to have erupted within the past 12,000 years; however, no historical activity has been recorded.

The summit elevation is high enough for the land surface to interact with cloud layers and with winds flowing past the island. In this image, two cloud layers are visible. The lower, more uniform layer consists of roughly parallel “cloud streets” that suggest the winds blowing out of the west. When air masses run into the summit of Île aux Cochons, moisture-laden air rises and cools, causing water vapor to condense into clouds.

Once the air masses pass over the summit, they descend and may encounter alternating moist and dry air layers, enabling the formation of the discontinuous, chevron-shaped wave clouds. While their appearance suggests that the clouds are forming in the wake of the island and moving eastwards, it is in fact the air mass that is moving, with clouds forming in regions of moist air and dissipating in dry regions.

Île aux Cochons is the westernmost of the islands in the sub-antarctic Crozet Archipelago, part of the French Southern and Antarctic Lands. Except for occasional research visits, the island is uninhabited. The island is an important breeding site for seabirds, including the world’s largest King Penguin colony.

Astronaut photograph ISS030-E-193144 was acquired on March 25, 2012, with a Nikon D2Xs digital camera using a 180 mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 30 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Caption by William L. Stefanov, Jacobs/ESCG at NASA-JSC.]]> 0 http://www.redorbit.com/media/gallery/earth/iod-earth-042912.jpg 2012-04-29 10:52:21
Activity began to intensify in mid-April 2012. The image above, captured by the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite, captured this view of Popocatépetl at 12:35 p.m. local time (16:35 Universal Time) on April 25, 2012.

A plume of steam and ash blows south from the volcano’s main vent. The ongoing eruption has flung hot rock fragments onto the northeast flank of the mountain, and a tan patch of what is probably new material—tephra—is visible just north of the main vent. Older lava flows are visible cutting into forests on the western slope. A portion of a cloud northwest of the main vent obscures part of the plume.

Popocatépetl, which means “smoking mountain” in the Aztec language, has seen low to moderate levels of activity throughout the past week. Other plumes similar to the one shown above have wafted from the volcano; an especially dense ash plume emerged on April 20th and drifted east at an altitude of 1.5 kilometers (0.9 miles). On April 18 and April 23, explosions sent hot, glowing rock fragments as far as 800 meters (874 yards) from the main vent; some of these fragments produced small mudslides, known as lahars.

On April 25, 2012, Mexico’s National Center for Disaster Prevention (CENAPRED) reported that Popocatépetl released bursts of steam, gas, and ash into the atmosphere at 1:00 p.m. and 5:26 p.m. local time; more than 13 low intensity “exhalations” of steam and gas occurred on the 26th, but only three contained ash.

Popo is situated between two large population centers: Mexico City (19 million) and Puebla (2.6 million). The region’s dense population means a serious eruption could have grave consequences. At a recent press conference, CENAPRED Director Roberto Quaas said scientists have no way of predicting whether the molten rock in the chamber will be slowly released or if it will erupt in a powerful explosion.

NASA Earth Observatory image by Jesse Allen, using EO-1 ALI data provided courtesy of the NASA EO-1 team. Caption by Adam Voiland with image interpretation from Erik Klemetti. ]]> 0