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Initial Conditions for the 2006 Atlantic Hurricane Season June 1, 2006

Posted by jtintle in Earth Observing System (EOS), Aqua, Atlantic Ocean, Earth, NASA, Planets, Satellite, Space Agencies, Space Fotos.
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Initial Conditions for the 2006 Atlantic Hurricane Season
 

Credit:

Earth Observing System (EOS), NASA, Earth Observatory

Description:

June 1 marks the first official day of hurricane season in the Atlantic Ocean. In 2006, conditions in the Atlantic were “hurricane friendly,” said NASA scientist David Adamec, but not quiet as extreme as they had been at the opening of the 2005 hurricane season. Hurricanes need both warm sea surface temperatures and calm winds to develop. Warm water provides both heat and humidity needed for storm formation. Strong winds would tear a developing storm apart, while calm winds allow a hurricane to build. In late May 2006, sea surface temperatures were warmer than normal, and winds were calm.

These images contrast sea surface temperatures on May 30, 2006, top, and May 30, 2005, bottom, as measured by the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) on NASA’s Aqua satellite. Red colors show regions where waters were warmer than the twelve-year average (1985-1997), while blue indicates cooler-than-average temperatures. White indicates average temperatures. In 2006, temperatures in the Atlantic were slightly warmer than average, particularly in the Caribbean, but strong southwest trade winds stirred the Gulf of Mexico, keeping the surface waters cool, said Adamec. In 2005, by contrast, the entire hurricane-prone section of the Atlantic was much warmer than average. In fact, at the opening of the 2006 hurricane season, sea surface temperatures were 2 degrees cooler than they had been at opening of the 2005 season, said Adamec. The warm temperatures in 2005 allowed a record seven storms to form by the end of July, one of which, Hurricane Emily, set records when it became first category 5 hurricane to occur in July. All other Atlantic storms of that strength have developed later in the season.

Though sea surface temperatures were not as extreme at the opening of the 2006 hurricane season as they were in 2005, the National Hurricane Center predicts a very active hurricane season with 13 to 16 named storms, 4 to 6 of which could become major hurricanes.

The other major difference between conditions in 2005 and conditions in 2006 is the position of the Bermuda High, a semi-permanent high-pressure system that sits over the Central Atlantic. Hurricanes that form in the Atlantic tend to circle the Bermuda High. In 2004 and 2005, the Bermuda High expanded to the south and west, pushing storms into the Gulf of Mexico and Florida. But as of May 31, 2006, the Bermuda High remained small and in a position that would steer storms up the East Coast of the United States or out into the Atlantic.

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Princess Astrid Ice Shelf December 15, 2005

Posted by jtintle in Earth Observing System (EOS), Antarctica, Aqua, Earth, Moderate Resolution Imaging Spectroradiometer, NASA, National Snow and Ice Data Center, Space Fotos, Terra satellite.
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Princess Astrid Ice Shelf Click here to view full image (77 kb)

Released in the fall of 2005, the MODIS Mosaic of Antarctica (MOA) has offered a new view of the frozen continent with unprecedented detail. The map is compiled from 260 images of Antarctica acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on NASA’s Terra and Aqua satellites. Using images collected between November 20, 2003, and February 29, 2004, MOA includes all land areas covered by the Antarctic Treaty. This MOA image shows part of the Princess Astrid Ice Shelf. Prominent on this ice shelf are features that glaciologists often study in Antarctica: blue ice and melt ponds.

Snow is composed of tiny ice crystals with many facets that reflect light like a mirror. Light shining into snow is bounced back largely unaltered, so snow appears white. Over time, however, compressed layers of snow turn to ice, and wind can expose this ice by sweeping away or evaporating lighter layers of snow. Compressed ice has big, clear crystals that allow light to travel through more of the ice before reflecting back. Ice absorbs a tiny amount of red light from the spectrum, so the light coming out of the ice appears blue to human eyes. Although MOA imagery is grayscale, blue ice nevertheless has a unique appearance in the imagery. In this image, windswept blue ice appears as swirling patchwork patterns of dark gray.

Melt ponds also appear in this image, showing up as curving lines of charcoal gray. Melt ponds have attracted the scrutiny of glaciologists because of the effects they have on ice shelves and glaciers. Warm summers can cause ponds of melt water to collect on the ice surface, and these ponds may eventually fill small cracks in the ice. Depending on the depth of a crack and the amount of water filling it, the water may deepen the crack, eventually carving all the way through the thick plate of ice. On a glacier, melt ponds can lead to water flow on the glacier’s underside, loosening it from the bedrock and accelerating flow. On an ice shelf, melt ponds can lead to ice shelf disintegration.

Image courtesy the National Snow and Ice Data Center, based on data from NASA’s Aqua and Terra MODIS sensors.

Kilauea Caldera December 10, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Hawaiian Volcano Observatory, Ikonos, Kilauea, NASA, Space Fotos, Volcano House, Volcanoes.
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Kilauea Caldera Click here to view full image (3760 kb)

Image copyright: Space Imaging

If you were to rank all of the volcanoes in the world in terms of activity, Kilauea would come out near the top. The volcano is so given to eruptions that it is said to be home to Pele, the temperamental Hawaiian volcano goddess. The most recent eruption began pouring from Kilauea’s east rift into the Pacific Ocean in 1983 and had not ceased as of December 8, 2005. Though no more than a lump on the eastern flanks of the massive Mauna Loa volcano on the Island of Hawaii, Kilauea has been prodigiously more productive than its neighbor. As much as ninety percent of Kilauea’s surface is less than 1,100 years old.

This Ikonos image, taken on January 14, 2003, shows Kilauea’s summit caldera, the surface of which is covered in fresh lava flows. The newer flows are dark, while the older flows pale as the iron in the lava oxidizes into rust. The oldest flow in the caldera is from 1882. The Halema`uma`u crater forms a pale circle in the southwest section of the caldera. As recently as 1924, the crater was filled with a molten lava lake. According to the Hawaiian Volcano Observatory (visible in the upper left corner of the image), the name comes from Polynesian mythology. “Halema`uma`u? refers to a house of ferns that Kamapua`a, a suitor of Pele, built over the crater to keep her from escaping. As the fresh flows in the image testify, the attempt was not successful. The other crater seen in the image, Keanakako`i, was the site of an eruption in 1974. In the upper right corner of the image is Volcano House, a private hotel.

Hurricane Epsilon December 7, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Goddard Space Flight Center, Hurricane Epsilon, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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Hurricane Epsilon Click here to view full image (4237 kb)

Explanation:
The official hurricane season in the Atlantic Ocean runs from June 1 to November 30 each year, but on very rare occasions, tropical storms and even hurricanes form outside the season. In 150 years of records, a hurricane has formed outside of the season on only four other occasions. But with so many records broken by the 2005 Atlantic hurricane season, it seems almost unsurprising to find Hurricane Epsilon ushering in December and bumping that out-of-season-hurricane record up to five storms. Epsilon formed in the Central Atlantic about halfway between the Azores Islands and Bermuda on November 29, 2005.

This image shows Hurricane Epsilon in the mid-Atlantic, as observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on December 4, 2005, at 13:30 UTC (10:30 a.m. local time). At that time, the hurricane had peak sustained winds of 140 kilometers per hour (85 miles per hour). That intensity appears to be the strongest the storm will achieve, according to forecasts from early on December 5, 2005. The storm had been sustaining winds from 120-140 kilometers per hour (75-85 mph) for roughly 48 hours at that time. This longevity ensures that Epsilon, despite having four other storms for company in the out-of-season-hurricane neighborhood, will nevertheless go down alone in the record books in at least one respect: it has broken a new record for the longest-lived December hurricane.

Image Credit: Jeff Schmaltz, MODIS Rapid Response Team,Goddard Space Flight Center

Topography of Popocatepetl December 2, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Mexico, NASA, Popocatépetl Volcano, Shuttle Radar Topography Mission (SRTM), Space Fotos, topography.
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Topography of Popocatepetl Click here to view full image (527 kb)

Explanation: Mexico’s Popocatépetl Volcano ushered in the new month with a moderate eruption on the morning of December 1, 2005. According to reports from the local monitoring station, an ash plume rose 5 kilometers above the summit and spread east-northeast, scattering a light ash fall onto nearby towns and cities. Several hours later a smaller ash column rose 2.5 kilometers above the volcano’s summit. As of December 1, 2005, scientists at the monitoring station had placed the volcanic alert level to yellow—indicating that those nearby should be aware that the volcano is active, should make basic emergency preparedness arrangements, and should remain alert for reports from authorities—but they were not anticipating a major eruption in coming days.

This image shows the topography of the Popocatépetl Volcano and the surrounding landscape in colors ranging from green (low elevation) to yellow to pink to white (highest elevation). Popocatépetl is a stratovolcano, the classic symmetrical (in this case cone-shaped) mountain with a circular crater in its summit. The volcano sits in the center of the image, its slopes rising from the surrounding plain and dissected by many cracks. To the east, scallop-edged raised areas show the location of hardened lava flows.

According to the Smithsonian Institution’s Global Volcanism Website, “At least three previous major cones [at Popocatépetl] were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits south of the volcano.? That history may explain why the southern portion of the volcano and the terrain to the south appear much more rugged than the area to the west and the east. North of Popocatépetl is a peak known as Iztaccihuatl, a 900,000-year-old volcano whose last eurptive episode was 80,000 years ago. The topographic map is made from data collected by the Space Shuttle Endeavour in February 2000 as part of the Shuttle Radar Topography Mission (SRTM).

The volcano is just an hour southeast of Mexico City, and it has a history of mild to moderate eruptions throughout the recorded history of the Aztecs and the Spanish. It had been dormant for many decades until an eruption in December 1996 opened a new chapter in the volcano’s eruptive history.

NASA image by Robert Simmon, based on SRTM data provided by the UMD Global Land Cover Facility

Karthala Volcano Erupts December 1, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Karthala, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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Karthala Volcano Erupts Click here to view full image (298 kb)

On November 24, 2005, Americans celebrated Thanksgiving. Halfway around the world, some 2,000 people fled their homes, hoping to escape the latest eruption of the Karthala Volcano. The volcano covered nearby villages in ash, and locals had little means of protecting their lungs besides covering their faces with scarves. As of November 28, one casualty (an infant) had been reported.

Karthala is one of two volcanoes that make up Grand Comore (or Ngazidja) Island in the Comoros archipelago. These islands lie in the Indian Ocean, between Africa and Madagascar. The Moderate Resolution Imaging Spectroradiometer (MODIS) flying onboard the Terra satellite captured this image on November 25, 2005. In this image, Grand Comore appears only in outline as material from the eruption completely obscures the satellite’s view of the land surface. The volcanic ash ranges in color from tan to beige. It has spread out around the volcano in all directions, but moves primarily eastward.

With an altitude of 2,361 meters (7,746 feet), Karthala is a shield volcano, with smooth slopes built from hardened lava. Comprising the southern portion of Grand Comore Island, Karthala is a regular troublemaker in its neighborhood. The volcano has erupted about 20 times in the last century, most recently in April 2005. The November 2005 eruption caused fears of lava floods and poisonous gases. The volcano had showed signs of trouble for several days before the eruption, and the ground continued to rumble afterwards.

Even after the volcano stopped erupting, trouble for the region was expected to continue. The November eruption fouled drinking water already made scarce by the region’s dry season. According to news reports, the UN Office for the Coordination of Humanitarian Affairs estimated that almost 120,000 people were without clean drinking water after the volcano dropped ash into water cisterns.

NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center

Ireland November 30, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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Ireland

Satellite: Terra
Date Acquired: 11/21/2005
Resolutions: 1km (238.2 KB)
500m (912.9 KB)
250m (2.4 MB)
Bands Used: 1, 4, 3
Credit: Jeff Schmaltz
MODIS Land Rapid Response Team,
NASA GSFC

Explanation: The rich and vibrant greens in this image depict the aptly-named “Emerald Isle?. Ireland (also called the ‘Republic of Ireland’) comprises about 5/6 of the island, while Northern Ireland, a region of the United Kingdom, encompasses the remaining portion. The darker colors in this image signify the coastal mountain ranges, while the lighter colors indicate the central lowlands or plains. In the past, forests covered the entire island, but the island was virtually stripped of its trees in the 17th century. Since then, agriculture has dominated the landscape, although currently Ireland’s economy is dominated by the industrial and service sectors. Ireland is located at high latitude (between 51.5 and 55.5 degrees North), but its climate is very mild: the average temperature in Winter is about 4 degrees Celsius (39 degrees Fahrenheit), while the average Summer temperature is about 16 degrees Celsius (61 degrees Fahrenheit). This condition is caused by the North Atlantic Current or Drift (of which the Gulf Stream is a part); warm water from the Gulf of Mexico is carried to the North Atlantic by strong ocean currents. Some of the water evaporates, making the water that remains much saltier and colder, and, therefore, more dense. It then sinks towards the ocean floor and is carried back in the direction from which it came. Recent research by NASA and other scientists indicates that this conveyor belt-like system may have been, and continue to be, disrupted by global warming.

The Caspian Sea November 29, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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The Caspian Sea

Satellite: Terra
Date Acquired: 11/21/2005
Resolutions: 1km (434.6 KB)
500m (1.5 MB)
250m (3.8 MB)
Bands Used: 1, 4, 3
Credit: Jeff Schmaltz
MODIS Land Rapid Response Team,
NASA GSFC

The Caspian Sea dominates this image at the crossroads of Europe and Asia. The Caspian is just Southwest of the Ural Mountains, the traditional dividing line between the two continents. It is bordered by Russia and Azerbaijan to the West, Kazakhstan to the North, Turkmenistan to the East, and Iran to the South. The Caspian is the largest inland body of water in the world, measuring over 370,000 square kilometers (143,000 square miles). It is fed by the Volga and Ural Rivers, but it has no natural outlet; instead, water is lost primarily through evaporation. It is relatively shallow, measuring only about a 1 kilometer (0.6 miles) deep; in contrast, the deepest lake in the world (Lake Baikal) is 1.6 kilometers (0.9 miles) deep but only about 31,000 square kilometers (12,000 square miles) in area. The Caspian, although sometimes classified as a lake, is comprised of salt, not fresh, water. The Caspian Sea is a major source of sturgeon, a highly valuable type of fish that produces most of the world’s caviar.

Cloud streets in Hudson Bay November 28, 2005

Posted by jtintle in Earth Observing System (EOS), Canada, Earth, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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Cloud streets in Hudson Bay

Satellite: Terra
Date Acquired: 11/21/2005
Resolutions: 1km (505 KB)
500m (1.9 MB)
250m (4.8 MB)
Bands Used: 1, 4, 3
Credit: Jeff Schmaltz
MODIS Land Rapid Response Team,
NASA GSFC

The striking patterns visible in this image are called “cloud streets?. Cloud streets are a regular feature of the middle and high latitudes; these are located within the Hudson Bay in Canada. Cloud streets form when cold air blows across the landscape and passes over warmer water. The cold air picks up energy from the warm water and rises (a process called “convection?) vertically. At the same time, the now-warmer air is being pushed horizontally by air currents. These competing forces produce vortices, pockets or masses of swirling air that resemble a tornado on its side. However, not all of the pockets are spin in the same direction; in fact, adjacent vortices spin in opposite directions. But they are all aligned in the direction of the prevailing winds, creating the linear patterns seen here. Sometimes the flow is interrupted by a land feature, such as an island. Then, the cloud streets produce interesting, paisley-like patterns known as von Karman cloud streets. These are named after the late Theodore von Karman, a professor of aeronautics and co-founder of NASA’s Jet Propulsion Laboratory at Caltech.

St. Petersburg and the Gulf of Finland November 28, 2005

Posted by jtintle in Earth Observing System (EOS), Astronaut, Earth, Expedition 11, Finland, International Space Station, NASA, Rocket, Space Fotos.
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St. Petersburg and the Gulf of Finland Click here to view full image (192 kb)

This strongly oblique (from the side) view shows the Gulf of Finland and Lake Ladoga in the late afternoon. At this time of day, sunglint—the reflection of sunlight into the camera lens—distinguishes the bodies of water from their surroundings. The image was taken from the International Space Station when the craft orbited north of the Caspian Sea, approximately 2,500 kilometers (1600 miles) to the southeast on the Russia-Kazakhstan border. Lakes in Finland in the middle of the view are 3,000 kilometers (1900 miles) from the camera.

The Neva River appears in sunglint, connecting Lake Ladoga to the gulf. Czar Peter the Great constructed St. Petersburg, starting in 1703, on the Neva River Delta. He established this city as his capital and window into Europe via the Baltic Sea. (Although not visible, St. Petersburg—the home town of Sergei Krikalev, Space Station commander when this picture was taken—lies on the Neva River delta.) In this view, taken with a powerful 400-millimeter lens, sunglint even reveals the causeways to Kotlin Island in the gulf—including some of the details of their construction. Oblique views reveal marked layers of gray haze generated by air pollution (top image, top of view), a common sight over Western Europe. Pollution also renders the bright glint areas a coppery color.

Below the photographs are a satellite view of St. Petersburg (left) and a map showing the location of the International Space Station at the time the photograph was taken (right).

Credit: Astronaut photograph 12401 was acquired July 10, 2005, with a Kodak 760C digital camera with a 400 mm lens, and is provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Group, Johnson Space Center

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