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Arctic Eclipse
NASA's Terra satellite was r …
8/4/08
Description NASA's Terra satellite was rounding the top of the globe, making its way from the eastern tip of Siberia and across the Arctic Ocean towards northern Norway and northwest Russia, when it captured this unique view of a total solar eclipse on Aug. 1, 2008. The circular disk of the Moon casts an oval-shaped shadow across the left edge of this image. In the region of totality, where the Moon entirely obscures the Sun, the shadow is complete. The edges of the shadow are fuzzy, gradually lightening from black to red, brown, and yellow until the shadow is no longer discernable. In these areas of semi-shadow, the Sun is only partially blocked. On any other day, the photo-like view captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite would be brilliant white since both the ever-present Arctic clouds and the ice that caps the northern sea reflect light. In this image, however, it is as if the world is painted in sepia: the low light casts a yellow-brown glow on much of the scene. The image was captured between 9:35 and 9:45 UTC. In the area shown in the image, the Sun was completely obscured for about two minutes. As Earth rotated, the shadow moved southeast across the surface. At the same time, the satellite crossed the Arctic, its path nearly perpendicular to the eclipse. Because the shadow was moving across Earth's surface as the satellite approached, it has a long oblong shape in this image. In an instantaneous snapshot from a platform that was not moving relative to Earth, the shadow would be more circular. Image credit: Jeff Schmaltz, NASA's MODIS Rapid Response Team Text credit: Holli Riebeek, NASA's Earth Observatory
Date 8/4/08
Global View of the Arctic Oc …
The Arctic Ocean has been ma …
8/21/00
Date 8/21/00
Description The Arctic Ocean has been mapped in an unprecedented manner by scientists at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif. Using advanced radar that sees through all weather conditions, researchers will now be able to determine how the Earth's warming may be changing the sea ice cover. Sea ice in the polar region is a large barometer of global climate conditions. The mission is a joint project between JPL and the Alaska Synthetic Aperture Radar Facility, University of Alaska, Fairbanks. JPL manages the Sea Ice Thickness Derived from High Resolution Radar Imagery project for NASA's Earth Science Enterprise, Washington, DC. The Earth Science Enterprise is dedicated to studying how natural and human-induced change affects our global environment. This image is posted on the World Wide Web at http://www.jpl.nasa.gov/pictures/seaice .
Comparative Views of Arctic …
Scientists at NASA's Jet Pro …
8/21/00
Date 8/21/00
Description Scientists at NASA's Jet Propulsion Laboratory (JPL) have used high resolution radar to see, for the first time ever, the development of the Arctic sea ice cover. The images show a comparison of ice growth during the Arctic winter. The two images are separated by nine days. Both images represent an area located in the Baufort Sea, north of the Alaskan coast. This radar view covers an area of 96 by 128 kilometers (60 by 80 miles). The brighter features are older thicker ice and the darker areas show young, recently formed ice. The earlier image is shown on the left. Within the nine-day span, large and extensive cracks in the ice cover have formed due to ice movement. These cracks expose the open ocean to the cold, frigid atmosphere where sea ice grows rapidly and thickens. Formation of sea ice in the Arctic Ocean affects the heat balance in the global atmosphere and ocean. The mission is a joint project between JPL and the Alaska Synthetic Aperture Radar Facility, University of Alaska, Fairbanks. JPL manages the Sea Ice Thickness Derived from High Resolution Radar Imagery project for NASA's Earth Science Enterprise, Washington, DC. The Earth Science Enterprise is dedicated to studying how natural and human-induced change affects our global environment. This image is available at http://www.jpl.nasa.gov/pictures/seaice . #####
Europa Exploration Concept
title Europa Exploration Concept
description Almost 30 years ago, NASA's Voyagers 1 and 2 (lower left) made their historic rendezvous with the Jupiter system and first revealed Europa's icy-covered surface. In 1995, the Galileo spacecraft entered orbit about Jupiter, and for years studied the giant planet and its major moons. From this mission we learned that Europa is a world covered with a global ocean about 100 kilometers (60 miles) deep, and that this ocean was capped, liked Earth's Arctic Ocean, with a shell of solid ice. To learn more about the ocean and the ice shell above, and especially to investigate the ocean's suitability to sustain life, will require the next step, a future mission dedicated to exploring Europa from orbit about the moon itself (center). Both NASA and the European Space Agency are actively studying the possibility of launching such a mission in the next 10 years. If a mission is launched, depending on what is found, future missions to Europa might involve landers or even autonomous vehicles, called cryobots (upper right), that melt through the ice to explore the ocean below, perhaps sometime later in this century. Credit: NASA/JPL
Minimum Sea Ice Extent (WMS)
Title Minimum Sea Ice Extent (WMS)
Abstract Each year, the ice covering the Arctic Ocean grows during the northern hemisphere winter and shrinks with the northern hemisphere summer. The ice extent is usually greatest during the month of March and is the least during the month of September. This image shows the average minimum extent of sea ice over the northern hemisphere during the month of September over 24 seasons, from 1979 - 2002. The red line shows the area where the average sea ice concentration is 15%.
Completed 2005-07-01
Minimum Sea Ice Extent (WMS)
Title Minimum Sea Ice Extent (WMS)
Abstract Each year, the ice covering the Arctic Ocean grows during the northern hemisphere winter and shrinks with the northern hemisphere summer. The ice extent is usually greatest during the month of March and is the least during the month of September. This image shows the average minimum extent of sea ice over the northern hemisphere during the month of September over 24 seasons, from 1979 - 2002. The red line shows the area where the average sea ice concentration is 15%.
Completed 2005-07-01
Bockfjorden
Title Bockfjorden
Description Far north within the Arctic Circle off the northern coast of Norway lies a small chain of islands known as Svalbard. These craggy islands have been scoured into shape by ice and sea. The effect of glacial activity can be seen in this image of the northern tip of the island of Spitsbergen. Here, glaciers have carved out a fjord, a U-shaped valley that has been flooded with sea water. Called Bockfjorden, the fjord is located at almost 80 degrees north, and it is still being affected by glaciers. The effect is most obvious in this image in the tan layer of silty freshwater that floats atop the denser blue water of the Arctic Ocean. The fresh water melts off land-bound glaciers and flows over the sandstone, collecting fine red-toned silt. In this image, the tan-colored fresh water flows northward up the fjord and is being pushed to the east side of the fjord by the rotation of the Earth. Glaciers here and elsewhere on Spitsbergen are cold bottom glaciers, which means that they are frozen to the ground rather than floating on top of a thin layer of melt water. The glaciers are also land glaciers since their terminus (end) lies on land, rather than floating on the water (a tidewater glacier). Land glaciers grow and retreat slowly, balancing fresh snow with the melting and draining of old ice. Their rate of growth or retreat can be affected by global warming. In most cases, including the glaciers around Bockfjorden, global warming has caused glaciers to retreat from increased melting. On the eastern side of Svalbard, however, glaciers are growing from enhanced snowfall. The reason for this pattern remains only one of many intriguing unanswered questions of Arctic science in the islands. The Advanced Spaceborne Thermal Emission and Reflection Radiometer, (ASTER [ http://asterweb.jpl.nasa.gov/ ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured this false-color image on June 26, 2001. The image was created by combining near-infrared, red, and green wavelenghts (ASTER bands 3, 2, & 1 respectively). NASA image created by Jesse Allen, Earth Observatory, using data obtained from the Goddard Earth Sciences DAAC [ http://daac.gsfc.nasa.gov/ ] courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov/ ]
Northwest Passage Open
Title Northwest Passage Open
Description Although nearly open, the Northwest Passage was not necessarily easy to navigate in August 2007. Located 800 kilometers (500 miles) north of the Arctic Circle and less than 1,930 kilometers (1,200 miles) from the North Pole, this sea route poses significant challenges, and the severe depletion of sea ice means only one of these is reduced. Nevertheless, long-term opening of the passage would have global impacts on trade and natural resource use. You can download a 250-meter-resolution KMZ file of the Northwest Passage [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Aug2007/nwpassage_amo_2007241.kmz ] suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image created by Jesse Allen, using data obtained from the Goddard Land Processes data archives (LAADS). [ http://laads.gsfc.nasa.gov/ ] Thanks to Walt Meier, NSIDC, U.S. National Ice Center, and John Falkingham, Environment Canada - Canadian Ice Service for image interpretation., For over 500 years, Arctic explorers have sought a passage between the North Atlantic and Pacific Oceans. Such a passage, often called the Northwest Passage, would connect Europe to Asia via shorter routes than the long voyage south around Africa. In 1497, English King Henry VII sent Italian explorer John Cabot to look for this hypothetical route and expeditions from some of the most famous explorers in the centuries that followed—Sir Francis Drake and Captain James Cook among them—met with failure. The combined efforts of a number of explorers eventually uncovered a winding path from the Atlantic to the Arctic and Pacific Oceans through the ice-bound islands of northern Canada. Even in modern times, navigating from the Atlantic to the Pacific through Canada's Arctic islands has been difficult. The summer of 2007, however, melted enough sea ice in Canada's far north to open up this long-sought passage. This image shows the islands north of mainland Canada adjacent to Greenland, as observed by the the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite on August 29, 2007. While the usual veil of clouds over the Arctic is visible through the scene, the sea ice pack that normally covers the water between the islands is absent. Areas often choked with ice at this time of year, but free of it in this MODIS scene, include the Parry and McClintock Channels and the McClure Strait. Larsen Sound and Victoria Strait are hidden beneath cloud cover, but they are also largely free of sea ice. [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17752 ] This provided a nearly ice-free connection between Baffin Bay (a long body of water between Canada's Baffin Island and Greenland that is regularly ice-free in summer) and the Arctic Ocean. An ice-free gap between the North American mainland and the Arctic sea, not shown here, extends all the way to the Bering Strait between Alaska and Russia, creating a connection almost free of all sea ice from the North Atlantic to the North Pacific. Multi-year ice (ice that survives more than one melt season) tends to be thicker and more resistant to melt than first-year ice (formed over just one winter). According to John Falkingham of the Canadian Ice Service, most of the multi-year ice melted from Victoria Strait and McClintock Channel in the summer of 2006, leaving these traditionally difficult areas more open. In mid-August 2007, only patchy areas of ice filled Victoria Strait and Larsen Sound. Falkingham described the Northwest Passage as "nearly open." Changes in the Northwest Passage were part of a larger pattern of melt in 2007 that also affected the East Siberian Sea. [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17743 ]
Flooding in Southern Siberia
Title Flooding in Southern Siberia
Description Springtime flooding in southern Siberia is not unusual. Melting snow fills the north-flowing rivers in the south even as upstream sections of the river are still frozen. Floods build up behind dams of ice, or simply build under the fast flow of spring runoff. Spring of 2006 was not exceptional. The Ob River of southern Siberia bulged with melted snow when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured the top image on May 7, 2006. A little over two weeks earlier, lower image, the river was still partially frozen, as evidenced by the strips of light blue ice on the river. Snow, pale blue here, was just beginning to melt on April 21. By May 7, most of the snow was gone, and the river had expanded out over its flood plain. Under the clouds along the right edge of the image is the city of Biysk, where 1,350 houses were flooded, according to news reports. Approximately 5,000 people had evacuated from the region. The Ob forms near Biysk where two smaller rivers converge. The smaller rivers flow out of the Altay Mountains of southern Russia and Mongolia near the borders of China and Kazakhstan. From the segment of the river shown here, the Ob will flow 3,700 kilometers (2,260 miles) north to the Kara Sea, a branch of the Arctic Ocean. NASA images created Jesse Allen, Earth Observatory, using data obtained from the Goddard Earth Sciences DAAC. [ http://daac.gsfc.nasa.gov/ ]
Flooding on the Ob River
Title Flooding on the Ob River
Description As much a sign of spring as longer days, greening plants, and melting snow, the Ob River had spread across its floodplain in far northern Russia when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured the top image on June 20, 2007. The Ob River and its tributary, the Irtysh, together form one of the longest river systems in Asia, flowing from the Altay Mountains of northern China to the Arctic Ocean. The northern reaches of the Ob flow over a flat, permafrost plain. As spring creeps north, the snow that covered northern Russia gradually melts, and the runoff flows into the river. Swollen with spring runoff, the river flows north, where it meets ice jams on sections of the river that have not thawed. Since the river cannot cut deep channels into the frozen land, it flows out over the surrounding plain during the spring melt, creating the wide band of water seen in this image. The lower image shows the Ob River in the fall, immediately before winter secured the region in its frozen grip. The river was a fraction of the size it would be the following spring. Both images were made using a combination of visible and infrared light. Water is black and dark blue. Snow, light blue, dusts the ground south of the Gulf of Ob in the October image and covers the peaks of the Ural Mountains west of the river in the June image. Also in the June image, a smooth pane of ice, also light blue, covers the Gulf of Ob, providing the natural dam that created the floods shown here. Pale blue, frozen lakes dot the permafrost north of the river, and darker, ice-free lakes adorn the land to the south of the river. Plant-covered land is green, and clouds are light blue and white. You can download a 250-meter-resolution KMZ file of the mouth of the Ob River [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jun2007/ob_tmo_2007171.kmz ] suitable for use with Google Earth. [ http://earth.google.com/ ] NASA images created by Jesse Allen, using data provided courtesy of the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team.
Flooding on the Ob River
Title Flooding on the Ob River
Description As much a sign of spring as longer days, greening plants, and melting snow, the Ob River had spread across its floodplain in far northern Russia when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured the top image on June 20, 2007. The Ob River and its tributary, the Irtysh, together form one of the longest river systems in Asia, flowing from the Altay Mountains of northern China to the Arctic Ocean. The northern reaches of the Ob flow over a flat, permafrost plain. As spring creeps north, the snow that covered northern Russia gradually melts, and the runoff flows into the river. Swollen with spring runoff, the river flows north, where it meets ice jams on sections of the river that have not thawed. Since the river cannot cut deep channels into the frozen land, it flows out over the surrounding plain during the spring melt, creating the wide band of water seen in this image. The lower image shows the Ob River in the fall, immediately before winter secured the region in its frozen grip. The river was a fraction of the size it would be the following spring. Both images were made using a combination of visible and infrared light. Water is black and dark blue. Snow, light blue, dusts the ground south of the Gulf of Ob in the October image and covers the peaks of the Ural Mountains west of the river in the June image. Also in the June image, a smooth pane of ice, also light blue, covers the Gulf of Ob, providing the natural dam that created the floods shown here. Pale blue, frozen lakes dot the permafrost north of the river, and darker, ice-free lakes adorn the land to the south of the river. Plant-covered land is green, and clouds are light blue and white. You can download a 250-meter-resolution KMZ file of the mouth of the Ob River [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jun2007/ob_tmo_2007171.kmz ] suitable for use with Google Earth. [ http://earth.google.com/ ] NASA images created by Jesse Allen, using data provided courtesy of the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team.
Flooding on the Ob River: Na …
nasa, nasanaturalhazards
* eoimages.gsfc.nasa.gov/ima …
ob_tmo_2007171
mediatype IMAGE
mediatype image
date 2007-06-20
creator NASA -- NASA Image Of The Day
identifier ob_tmo_2007171
Ellesmere Island National Pa …
nasa, nasaimageofthedaygalle …
The northeastern corner of E …
aster_ellesmere_04aug03
mediatype IMAGE
mediatype image
date 2003-08-04
creator NASA -- Data made available by NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan asterweb.jpl.nasa.gov/ ASTER Science Team
identifier aster_ellesmere_04aug03
Distinguishing Clouds from I …
nasa, nasaimageofthedaygalle …
As a consequence of its capa …
PIA03717
mediatype IMAGE
mediatype image
date 2002-05-28
creator NASA -- Image courtesy NASA/GSFC/LaRC/JPL, www-misr.jpl.nasa.gov/ MISR Team
identifier PIA03717
Fires Across the Central Sib …
nasa, nasaimageofthedaygalle …
Forest fires were burning ac …
ge_06779
mediatype IMAGE
mediatype image
date 2006-07-24
creator NASA -- NASA image by Jeff Schmaltz, rapidfire.sci.gsfc.nasa.gov MODIS Rapid Response Team, Goddard Space Flight Center.
identifier ge_06779
Fires Across the Central Sib …
nasa, nasaimageofthedaygalle …
Forest fires were burning ac …
ge_06779
mediatype IMAGE
mediatype image
date 2006-07-24
creator NASA -- NASA image by Jeff Schmaltz, rapidfire.sci.gsfc.nasa.gov MODIS Rapid Response Team, Goddard Space Flight Center.
identifier ge_06779
Clouds over Ice: Image of th …
nasa, nasaimageofthedaygalle …
In a photo-like satellite im …
ge_07378
mediatype IMAGE
mediatype image
date 2004
creator NASA -- NASA images by Robert Simmon and Jesse Allen, based on modarch.gsfc.nasa.gov/ MODIS data.
identifier ge_07378
Clouds over Ice: Image of th …
nasa, nasaimageofthedaygalle …
In a photo-like satellite im …
ge_07378
mediatype IMAGE
mediatype image
date 2004
creator NASA -- NASA images by Robert Simmon and Jesse Allen, based on modarch.gsfc.nasa.gov/ MODIS data.
identifier ge_07378
Clouds over Ice: Image of th …
nasa, nasaimageofthedaygalle …
In a photo-like satellite im …
ge_07378
mediatype IMAGE
mediatype image
date 2004
creator NASA -- NASA images by Robert Simmon and Jesse Allen, based on modarch.gsfc.nasa.gov/ MODIS data.
identifier ge_07378
Clouds over Ice: Image of th …
nasa, nasaimageofthedaygalle …
In a photo-like satellite im …
ge_07378
mediatype IMAGE
mediatype image
date 2004
creator NASA -- NASA images by Robert Simmon and Jesse Allen, based on modarch.gsfc.nasa.gov/ MODIS data.
identifier ge_07378
Detailed View of Arctic Sea …
nasa, nasaimageofthedaygalle …
For many years, scientists h …
ge_07370
mediatype IMAGE
mediatype image
date 2001-06-16
creator NASA -- NASA image by Robert Simmon, based on Landsat-7 data from the glcf.umiacs.umd.edu/index.shtml Global Land Cover Facility.
identifier ge_07370
Detailed View of Arctic Sea …
nasa, nasaimageofthedaygalle …
For many years, scientists h …
ge_07370
mediatype IMAGE
mediatype image
date 2001-06-16
creator NASA -- NASA image by Robert Simmon, based on Landsat-7 data from the glcf.umiacs.umd.edu/index.shtml Global Land Cover Facility.
identifier ge_07370
Flooding in Southern Siberia …
nasa, nasanaturalhazards
* eoimages.gsfc.nasa.gov/ima …
siberia_tmo_2006127
mediatype IMAGE
mediatype image
date 2006-05-02
creator NASA -- NASA Image Of The Day
identifier siberia_tmo_2006127
Northwest Passage Open: Natu …
nasa, nasanaturalhazards
For over 500 years, Arctic e …
nwpassage_amo_2007241
mediatype IMAGE
mediatype image
date 2007-08-29
creator NASA -- NASA Image Of The Day
identifier nwpassage_amo_2007241
Global View of the Arctic Oc …
PIA02970
Sol (our sun)
Imaging Radar
Title Global View of the Arctic Ocean
Original Caption Released with Image NASA researchers have new insights into the mysteries of Arctic sea ice, thanks to the unique abilities of Canada's Radarsat satellite. The Arctic is the smallest of the world's four oceans, but it may play a large role in helping scientists monitor Earth's climate shifts. Using Radarsat's special sensors to take images at night and to peer through clouds, NASA researchers can now see the complete ice cover of the Arctic. This allows tracking of any shifts and changes, in unprecedented detail, over the course of an entire winter. The radar-generated, high-resolution images are up to 100 times better than those taken by previous satellites. Using this new information, scientists at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., can generate comprehensive maps of Arctic sea ice thickness for the first time. "Before we knew only the extent of the ice cover," said Dr. Ronald Kwok, JPL principal investigator of a project called Sea Ice Thickness Derived From High Resolution Radar Imagery. "We also knew that the sea ice extent had decreased over the last 20 years, but we knew very little about ice thickness.""Since sea ice is very thin, about 3 meters (10 feet) or less,"Kwok explained, "it is very sensitive to climate change." Until now, observations of polar sea ice thickness have been available for specific areas, but not for the entire polar region. The new radar mapping technique has also given scientists a close look at how the sea ice cover grows and contorts over time. "Using this new data set, we have the first estimates of how much ice has been produced and where it formed during the winter. We have never been able to do this before, " said Kwok. "Through our radar maps of the Arctic Ocean, we can actually see ice breaking apart and thin ice growth in the new openings. " RADARSAT gives researchers a piece of the overall puzzle every three days by creating a complete image of the Arctic. NASA scientists then put those puzzle pieces together to create a time-lapsed view of this remote and inhospitable region. So far, they have processed one season's worth of images."We can see large cracks in the ice cover, where most ice grows, " said Kwok. "These cracks are much longer than previously thought, some as long as 2,000 kilometers (1,200 miles)," Kwok continued. "If the ice is thinning due to warming, we'll expect to see more of these long cracks over the Arctic Ocean. " Scientists believe this is one of the most significant breakthroughs in the last two decades of ice research. "We are now in a position to better understand the sea ice cover and the role of the Arctic Ocean in global climate change, " said Kwok. Radar can see through clouds and any kind of weather system, day or night, and as the Arctic regions are usually cloud-covered and subject to long, dark winters, radar is proving to be extremely useful. However, compiling these data into extremely detailed pictures of the Arctic is a challenging task."This is truly, a major innovation in terms of the quantities of data being processed and the novelty of the methods being used, " said Verne Kaupp, director of the Alaska SAR Facility at the University of Alaska, Fairbanks. The mission is a joint project between JPL, the Alaska SAR Facility, and the Canadian Space Agency. Launched by NASA in 1995, the Radarsat satellite is operated by the Canadian Space Agency. JPL manages the Sea Ice Thickness Derived From High Resolution Radar Imagery project for NASA's Earth Science Enterprise, Washington, DC. The Earth Science Enterprise is dedicated to studying how natural and human-induced changes affect our global environment.
Comparative Views of Arctic …
PIA02971
Sol (our sun)
Imaging Radar
Title Comparative Views of Arctic Sea Ice Growth
Original Caption Released with Image NASA researchers have new insights into the mysteries of Arctic sea ice, thanks to the unique abilities of Canada's Radarsat satellite. The Arctic is the smallest of the world's four oceans, but it may play a large role in helping scientists monitor Earth's climate shifts. Using Radarsat's special sensors to take images at night and to peer through clouds, NASA researchers can now see the complete ice cover of the Arctic. This allows tracking of any shifts and changes, in unprecedented detail, over the course of an entire winter. The radar-generated, high-resolution images are up to 100 times better than those taken by previous satellites. The two images above are separated by nine days (earlier image on the left). Both images represent an area (approximately 96 by 128 kilometers, 60 by 80 miles)located in the Baufort Sea, north of the Alaskan coast. The brighter features are older thicker ice and the darker areas show young, recently formed ice. Within the nine-day span, large and extensive cracks in the ice cover have formed due to ice movement. These cracks expose the open ocean to the cold, frigid atmosphere where sea ice grows rapidly and thickens. Using this new information, scientists at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., can generate comprehensive maps of Arctic sea ice thickness for the first time. "Before we knew only the extent of the ice cover," said Dr. Ronald Kwok, JPL principal investigator of a project called Sea Ice Thickness Derived From High Resolution Radar Imagery. "We also knew that the sea ice extent had decreased over the last 20 years, but we knew very little about ice thickness.""Since sea ice is very thin, about 3 meters (10 feet) or less,"Kwok explained, "it is very sensitive to climate change." Until now, observations of polar sea ice thickness have been available for specific areas, but not for the entire polar region. The new radar mapping technique has also given scientists a close look at how the sea ice cover grows and contorts over time. "Using this new data set, we have the first estimates of how much ice has been produced and where it formed during the winter. We have never been able to do this before," said Kwok. "Through our radar maps of the Arctic Ocean, we can actually see ice breaking apart and thin ice growth in the new openings." RADARSAT gives researchers a piece of the overall puzzle every three days by creating a complete image of the Arctic. NASA scientists then put those puzzle pieces together to create a time-lapsed view of this remote and inhospitable region. So far, they have processed one season's worth of images."We can see large cracks in the ice cover, where most ice grows," said Kwok. "These cracks are much longer than previously thought, some as long as 2,000 kilometers (1,200 miles)," Kwok continued. "If the ice is thinning due to warming, we'll expect to see more of these long cracks over the Arctic Ocean." Scientists believe this is one of the most, significant breakthroughs in the last two decades of ice research. "We are now in a position to better understand the sea ice cover and the role of the Arctic Ocean in global climate change," said Kwok. Radar can see through clouds and any kind of weather system, day or night, and as the Arctic regions are usually cloud-covered and subject to long, dark winters, radar is proving to be extremely useful. However, compiling these data into extremely detailed pictures of the Arctic is a challenging task."This is truly a major innovation in terms of the quantities of data being processed and the novelty of the methods being used," said Verne Kaupp, director of the Alaska SAR Facility at the University of Alaska, Fairbanks. The mission is a joint project between JPL, the Alaska SAR Facility, and the Canadian Space Agency. Launched by NASA in 1995, the Radarsat satellite is operated by the Canadian Space Agency. JPL manages the Sea Ice Thickness Derived From High Resolution Radar Imagery project for NASA's Earth Science Enterprise, Washington, DC. The Earth Science Enterprise is dedicated to studying how natural and human-induced changes affect our global environment.
MISR Sights the Bering Strai …
PIA02638
Sol (our sun)
Multi-angle Imaging SpectroR …
Title MISR Sights the Bering Strait
Original Caption Released with Image With the Seward Peninsula of Alaska to the east, and Chukotskiy Poluostrov of Siberia to the west, the Bering Strait separates the United States and the Russian Federation by only 90 kilometers. It is named for Danish explorer Vitus Bering, who spotted the Alaskan mainland in 1741 while leading an expedition of Russian sailors. This view of the region was captured by MISR's vertical-viewing (nadir) camera on August 18, 2000 during Terra orbit 3562. The boundary between the US and Russia lies between Big and Little Diomede Islands, which are visible in the middle of the Bering Strait. The Arctic Circle, at 66.5 degrees north latitude, runs through the Arctic Ocean in the top part of this image. This circle marks the southernmost latitude for which the Sun does not rise above the horizon on the day of the winter solstice. At the bottom of this image is St. Lawrence Island. Situated in the Bering Sea, it is part of Alaska and home to Yupik Eskimos. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. For more information: http://www-misr.jpl.nasa.gov
Distinguishing Clouds from I …
PIA03717
Sol (our sun)
Multi-angle Imaging SpectroR …
Title Distinguishing Clouds from Ice over the East Siberian Sea, Russia
Original Caption Released with Image As a consequence of its capability to retrieve cloud-top elevations, stereoscopic observations from the Multi-angle Imaging SpectroRadiometer (MISR) can discriminate clouds from snow and ice. The central portion of Russia's East Siberian Sea, including one of the New Siberian Islands, Novaya Sibir, are portrayed in these views from data acquired on May 28, 2002. The left-hand image is a natural color view from MISR's nadir camera. On the right is a height field retrieved using automated computer processing of data from multiple MISR cameras. Although both clouds and ice appear white in the natural color view, the stereoscopic retrievals are able to identify elevated clouds based on the geometric parallax which results when they are observed from different angles. Owing to their elevation above sea level, clouds are mapped as green and yellow areas, whereas land, sea ice, and very low clouds appear blue and purple. Purple, in particular, denotes elevations very close to sea level. The island of Novaya Sibir is located in the lower left of the images. It can be identified in the natural color view as the dark area surrounded by an expanse of fast ice. In the stereo map the island appears as a blue region indicating its elevation of less than 100 meters above sea level. Areas where the automated stereo processing failed due to lack of sufficient spatial contrast are shown in dark gray. The northern edge of the Siberian mainland can be found at the very bottom of the panels, and is located a little over 250 kilometers south of Novaya Sibir. Pack ice containing numerous fragmented ice floes surrounds the fast ice, and narrow areas of open ocean are visible. The East Siberian Sea is part of the Arctic Ocean and is ice-covered most of the year. The New Siberian Islands are almost always covered by snow and ice, and tundra vegetation is very scant. Despite continuous sunlight from the end of April until the middle of August, the ice between the island and the mainland typically remains until August or September. The Multi-angle Imaging SpectroRadiometer views almost the entire Earth every 9 days. These images were acquired during Terra orbit 12986 and cover an area of about 380 kilometers x 1117 kilometers. They utilize data from blocks 24 to 32 within World Reference System-2 path 117. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.
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