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Images of Austria and Goddard Space Flight Center (GSFC)
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Dust Storm over the Mediterr
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| Title |
Dust Storm over the Mediterranean Sea |
| Description |
The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) observed this large cloud of dust (brownish pixels) blowing from northern Africa across the Mediterranean Sea on March 4, 2002. The dust can be seen clearly blowing across Southern Italy, Albania, Greece, and Turkey?all along the Mediterranean?s northeastern shoreline. Notice that there also appears to be human-made aerosol pollution (greyish pixels) pooling in the air just south of the Italian Alps and blowing southeastward over the Adriatic Sea. The Alps can be easily identified as the crescent-shaped, snow-capped mountain range in the top center of this true-color scene. There also appears to be a similar haze over Austria, Hungary, and Yugoslavia to the north and east of Italy. SeaWiFS image courtesy the SeaWiFS Project, [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://seawifs.gsfc.nasa.gov/SEAWIFS.html ] NASA/Goddard Space Flight Center, and ORBIMAGE |
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European Heat Wave
| Title |
European Heat Wave |
| Description |
Europe is experiencing an historic heat wave that has been responsible for at 3,000 deaths in France alone. Compared to July 2001, temperatures in July 2003 were sizzling. This image shows the differences in day time land surface temperatures collected in the two years by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite. A blanket of deep red across southern and eastern France (left of image center) shows where temperatures were 10 degrees Celsius (18 degrees Fahrenheit) hotter this summer. White areas show where temperatures were similar, and blue shows where temperatures were cooler in 2003 than 2001. Even the Alps, which arc across southeastern France, Switzerland, Austria, and northern Italy (just below image center), are very warm this year. Glaciers are melting rapidly and swelling rivers and lakes to dangerously high levels. Climbers had to be evacuated from Switzerland's famous Matterhorn after melting triggered the collapse of a rock face. The popular climbing destination has been closed while geologists assess the possibility of further collapses. The heat wave stretches northward all the way to the United Kingdom, particularly southern England (bottom of island) and Scotland (top of island). In London, trains were shut down over fears that tracks would buckle in the heat, while in Scotland the high temperatures combined with falling water levels in rivers and streams are threatening the spawning and survival of salmon. Throughout France, Spain, Portugal, and Italy, the intense heat and dry conditions sparked devastating forest fires that killed at least 15 people. Image by Reto Stockli and Robert Simmon, NASA?s Earth Observatory Team. |
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Flooding on Elbe River
| Title |
Flooding on Elbe River |
| Description |
Heavy rains in Central Europe over the past few weeks have led to some of the worst flooding the region has witnessed in more than a century. The floods have killed more than 100 people in Germany, Russia, Austria, Hungary, and the Czech Republic and have led to as much as $20 billion in damage. This false-color image of the Elbe River and its tributaries was taken on August 18, 2002, by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA?s Terra satellite. Portions of the Elbe River rose from the usual summer high of 6 feet (1.8 meters) to over 30 feet (9.1 meters). In the Czech Republic capital of Prague, which sits at the lower right-hand corner of the image, residential streets filled with water and thousands were evacuated from their homes. Further north in Dresden, Germany, the floods reached levels not seen since 1845. The water seeped into the historic buildings and threatened precious works of art. City officials estimate that the damage to Dresden will probably exceed $100 million. As the floodwaters moved north over the weekend, thousands of people abandoned the cities of Magdeburge and Bitterfeld, Germany, and rescue workers lined the exposed riverbanks with sandbags. German meteorologists expect the flooding to subside over the next week as little rain is expected. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC |
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Floods in Central Europe
| Title |
Floods in Central Europe |
| Description |
The rivers of Central Europe spilled over their banks in late March and early April 2006. Filled with heavy rain and spring runoff, the flooded rivers forced thousands to evacuate, according to news reports. Among the most severely affected regions were northeast Austria and western Slovakia, shown in this Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) image taken by the Terra [ http://terra.nasa.gov/ ] satellite. The Morava River, which forms the border between the two countries, was a wide blue ribbon on April 7, 2006, top. Dams along the river were strained, reported the Associated Press, and one burst under the onslaught of excess water. The Danube River, shown in the lower left corner of the image, had also been flooded, but the section of the river shown here appeared to have subsided to normal conditions by April 7. The lower image, taken on March 24, is provided to show the region under normal conditions, though the Danube may already have been running high at that point. The large images provided above are at MODIS' maximum resolution of 250 meters per pixel. The MODIS Rapid Response Team provides daily images [ http://rapidfire.sci.gsfc.nasa.gov/fas/?Europe_2_03 ] of the region in a variety of resolutions. NASA images courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
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Floods in Central Europe
| Title |
Floods in Central Europe |
| Description |
The rivers of Central Europe spilled over their banks in late March and early April 2006. Filled with heavy rain and spring runoff, the flooded rivers forced thousands to evacuate, according to news reports. Among the most severely affected regions were northeast Austria and western Slovakia, shown in this Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) image taken by the Terra [ http://terra.nasa.gov/ ] satellite. The Morava River, which forms the border between the two countries, was a wide blue ribbon on April 7, 2006, top. Dams along the river were strained, reported the Associated Press, and one burst under the onslaught of excess water. The Danube River, shown in the lower left corner of the image, had also been flooded, but the section of the river shown here appeared to have subsided to normal conditions by April 7. The lower image, taken on March 24, is provided to show the region under normal conditions, though the Danube may already have been running high at that point. The large images provided above are at MODIS' maximum resolution of 250 meters per pixel. The MODIS Rapid Response Team provides daily images [ http://rapidfire.sci.gsfc.nasa.gov/fas/?Europe_2_03 ] of the region in a variety of resolutions. NASA images courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
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Mir Dreams
| Title |
Mir Dreams |
| Explanation |
This dream-like image of Mir [ http://www.hq.nasa.gov/osf/mir/ ] was recorded by astronauts as the Space Shuttle Atlantis [ http://kids.msfc.nasa.gov/Rockets/ShuttleNames.asp ] approached the Russian space station prior to docking during the STS-76 mission [ http://spaceflight.nasa.gov/shuttle/archives/sts-76/ index.html ]. Sporting spindly appendages and solar panels, Mir resembles a whimsical flying insect hovering about 350 kilometers above New Zealand's [ http://www.rasnz.org.nz/index.htm ] South Island and the city of Nelson [ http://webnz.com/nelsonarts/foundations.html ], near Cook Strait [ http://www.south-pole.com/p0000071.htm ]. In late March 1996, Atlantis shuttled astronaut Shannon W. Lucid [ http://www.jsc.nasa.gov/Bios/htmlbios/lucid.html ] to Mir for a five month visit, increasing Mir's occupancy from 2 to 3. It returned to pick Lucid up and drop off astronaut John Blaha [ http://www.jsc.nasa.gov/Bios/htmlbios/blaha.html ] during the STS-79 mission [ http://www.ksc.nasa.gov/shuttle/missions/sts-79/mission-sts-79.html ] in August of that year. Since becoming operational in 1986, Mir has [ http://www.hq.nasa.gov/osf/mir/mirvis.html ] been visited by over 100 spacefarers from the nations of planet Earth including, Russia, the United States, Great Britain, Germany, France, Japan, Austria, Kazakhstan and Slovakia. After joint Shuttle-Mir [ http://spaceflight.nasa.gov/history/shuttle-mir/ ] training missions in support of the International Space Station [ http://spaceflight.nasa.gov/station/index.html ], continuous occupation of Mir ended in August 1999. Mir is still in orbit and its operation is now being pursued by commercial interests [ http://www.mirstation.com/index.html ]. |
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Eclipsed Moon and Stars
| Title |
Eclipsed Moon and Stars |
| Explanation |
This dramatic image [ http://panther-observatory.com/gallery/moon/doc/ Mofi_03032007_cass.htm ] features a dark red Moon during a total lunar eclipse -- celestial shadow play [ http://antwrp.gsfc.nasa.gov/apod/ap060909.html ] enjoyed by many denizens of planet Earth [ http://spaceweather.com/eclipses/gallery_03mar07.htm ] last Saturday. Recorded near Wildon, Austria, the picture is a composite of two exposures, a relatively short exposure to feature the lunar surface and a longer exposure to capture background stars in the constellation Leo [ http://www.seds.org/Maps/Stars_en/Fig/leo.html ]. Completely immersed in Earth's cone-shaped shadow during the total eclipse [ http://www.inconstantmoon.com/cyc_ecl1.htm ] phase, the lunar surface is still illuminated by sunlight, reddened and [ http://antwrp.gsfc.nasa.gov/apod/ap031121.html ] refracted into the dark shadow region by a dusty atmosphere. As a result, familiar [ http://antwrp.gsfc.nasa.gov/apod/ap031212.html ] details of the Moon's nearside are easy to pick out, including the smooth lunar mare and the large ray crater Tycho [ http://antwrp.gsfc.nasa.gov/apod/ap050305.html ]. In this telescopic view, the background stars are faint and most would be invisible to the naked eye. |
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Announcing Comet Hale-Bopp
| Title |
Announcing Comet Hale-Bopp |
| Explanation |
The pictured fuzzy patch may become one of the most spectacular comets this century. Although it is very hard to predict how bright a comet [ http://seds.lpl.arizona.edu/billa/tnp/comets.html ] will become, Comet Hale-Bopp [ http://encke.jpl.nasa.gov/hale_bopp_info.html ], named for its discoverers [ http://encke.jpl.nasa.gov/hale_bopp/discoverers.html ], was spotted farther from the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ] than any previous comet - a good sign that it could become very bright, easily visible to the naked eye. This picture was taken on July 25th 1995, only two days after its discovery. A comet [ http://www.c3.lanl.gov/~cjhamil/SolarSystem/comet.html ] bright enough to see without a telescope occurs only about once a decade. The large coma [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#coma ] and long tail [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#comet ] of bright comets are so unusual and impressive that they have been considered omens of change by many cultures. A comet does not streak by in few seconds - but it may change its position and structure noticeably from night to night. Tomorrow's picture: An Orbiting Iceberg |
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Mir Dreams
| Title |
Mir Dreams |
| Explanation |
This dream [ http://www.pbs.org/wgbh/nova/mir/day.html ]-like image of Mir [ http://www.pbs.org/wgbh/nova/mir/tour.html ] was recorded by astronauts as the Space Shuttle Atlantis [ http://kids.msfc.nasa.gov/Rockets/ShuttleNames.asp ] approached the Russian space station prior to docking during the STS-76 mission. Sporting spindly appendages and solar panels, Mir resembles a whimsical flying insect hovering about 350 kilometers above New Zealand's [ http://www.rasnz.org.nz/index.htm ] South Island and the city of Nelson near Cook Strait [ http://www.south-pole.com/p0000071.htm ]. In late March 1996, Atlantis shuttled astronaut Shannon W. Lucid [ http://www.jsc.nasa.gov/Bios/htmlbios/lucid.html ] to Mir for a five month visit, increasing Mir's occupancy from 2 to 3. It returned to pick Lucid up and drop off astronaut John Blaha [ http://www.jsc.nasa.gov/Bios/htmlbios/blaha.html ] during the STS-79 mission [ http://www.ksc.nasa.gov/shuttle/missions/sts-79/mission-sts-79.html ] in August of that year. Since becoming operational in 1986, Mir has [ http://www.cosmicimages.com/Mir/index.html ] been visited by over 100 spacefarers from the nations of planet Earth including, Russia, the United States, Great Britain, Germany, France, Japan, Austria, Kazakhstan and Slovakia. After joint Shuttle-Mir [ http://spaceflight.nasa.gov/history/shuttle-mir/ ] training missions in support of the International Space Station [ http://spaceflight.nasa.gov/station/index.html ], continuous occupation of Mir ended in August 1999. The Mir was deorbited [ http://antwrp.gsfc.nasa.gov/apod/ap010323.html ] in March 2001. |
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Clouds and the Moon Move to
…
| Title |
Clouds and the Moon Move to Block the Sun |
| Explanation |
High above a small church near Vienna, Austria [ http://www.cia.gov/cia/publications/factbook/geos/au.html ], clouds and the Moon vied for position in front of the Sun. Such was the case on the ground late last month during a partial eclipse of the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap030606.html ] visible throughout Europe and Asia [ http://www.askasia.org/image/maps/asia.htm ]. Nearing the farthest part of its orbit [ http://www.windows.ucar.edu/tour/link=/the_universe/uts/moon1.html ] around the Earth [ http://www.nineplanets.org/earth.html ], the Moon's angular size [ http://antwrp.gsfc.nasa.gov/apod/ap010218.html ] was too small to block [ http://www.earthview.com/tutorial/causes.htm ] the entire Sun, a situation that would have resulted in a total solar eclipse [ http://antwrp.gsfc.nasa.gov/apod/ap010408.html ]. The next solar eclipse visible from Earth will occur on November 23. Although a total eclipse [ http://www.exploratorium.edu/eclipse/ ] will be visible only from parts of Antarctica [ http://antwrp.gsfc.nasa.gov/apod/ap991116.html ], parts of the Sun will momentarily disappear for observers across Australia [ http://www.cia.gov/cia/publications/factbook/geos/as.html ], New Zealand [ http://www.cia.gov/cia/publications/factbook/geos/nz.html ], and the southernmost tip of South America [ http://www.infoplease.com/atlas/southamerica.html ]. |
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Cyg X-1: Can Black Holes For
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| Title |
Cyg X-1: Can Black Holes Form in the Dark? |
| Explanation |
The formation of a black hole [ http://imagine.gsfc.nasa.gov/docs/science/know_l2/ black_holes.html ] from the collapsing core of a massive star is thought to be heralded by a spectacular supernova explosion. Such an extremely energetic collapse is also a leading explanation [ http://arxiv.org/abs/astro-ph/0304173 ] for the mysterious cosmic gamma-ray bursts [ http://antwrp.gsfc.nasa.gov/apod/ap020228.html ]. But researchers now suggest that the Milky Way's most famous black hole, Cygnus X-1 [ http://www.eso.org/outreach/eduoff/catchastar/cas-projects/ austria_cygnus_1/ ], was born when a massive star collapsed -- without any supernova explosion [ http://arxiv.org/abs/astro-ph/0305205 ] at all. Their dynamical evidence is summarized in this color image of a gorgeous region in Cygnus [ http://imagine.gsfc.nasa.gov/YBA/cyg-X1-mass/ cygX1-more3.html ], showing Cyg X-1 and a cluster of massive stars (yellow circles) known as Cygnus OB3. Arrows compare the measured direction and speed of Cyg X-1 and the average direction and speed of the massive stars of Cyg OB3. The similar motions indicate that Cyg X-1's progenitor star was itself a cluster member and that its path was not altered at all when it became a black hole. In contrast, if Cyg X-1 were born in a violent supernova it would have likely received a fierce kick [ http://hubblesite.org/newscenter/archive/2002/30/ ], changing its course. If not a supernova, could the formation [ http://saturn.sron.nl/~erikk/v4641sgr/ ] of the Cyg X-1 black hole have produced a dark [ http://swift.gsfc.nasa.gov/public/news/ archive/2002/02-257.html ] gamma-ray burst in the Milky Way [ http://www.pbs.org/wgbh/nova/gamma/milkyway.html ]? |
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Mars Moons
| Title |
Mars Moons |
| Explanation |
This year's record close approach [ http://www.planetary.org/html/news/articlearchive/headlines/ 2003/mars_closest-approach.html ] of Mars inspired many [ http://antwrp.gsfc.nasa.gov/apod/ap030902.html ] to enjoy telescopic views [ http://antwrp.gsfc.nasa.gov/apod/ap030724.html ] of the red planet. But while Mars was so bright it was hard to miss, spotting Mars' two diminutive moons was still a good test for observers [ http://www.lpl.arizona.edu/~rhill/alpo/marstuff/ recobs.html ] with modest sized instruments. Mars' moons were discovered in August [ http://www.usno.navy.mil/hallmedal.html ] of 1877 by Asaph Hall at the US Naval Observatory using the large 26-inch Alvan Clark refractor [ http://www.usno.navy.mil/USNO26in.shtml ]. Recorded on this August 22nd, innermost moon Phobos [ http://antwrp.gsfc.nasa.gov/apod/ap030406.html ] and outermost moon Deimos [ http://antwrp.gsfc.nasa.gov/apod/ap010902.html ] are seen here against the planet's glare in a digital composite image. The picture consists of of a long exposure capturing the faint, city-sized moons and overexposing the planetary disk, combined with a well exposed image of the red planet, revealing dark markings [ http://www.bibliomania.com/2/1/69/116/ frameset.html ] on the surface and the white south polar cap. The images were taken [ http://panther-observatory.com/Mars2003.htm ] by astronomer Johannes Schedler using an 11-inch Schmidt-Cassegrain telescope at his observatory in southeastern Austria. ("Editor's note:" For help finding Mars' moons, just put your cursor over the image.) |
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A Window to the Once Secret
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| Title |
A Window to the Once Secret Sky |
| Explanation |
If there were a window nearby to the distant universe -- would you look through it? Quite possibly, there is, in the form of a small telescope [ http://www.yesmag.bc.ca/how_work/telescope.html ]. A local skykeeper could be a relative [ http://images.google.com/images?hl=en&lr=&q=relatives ] or a stranger and is frequently proud to show off the sky free [ http://antwrp.gsfc.nasa.gov/apod/ap040808.html ] of charge. Through a window called an eyepiece [ http://observers.org/beginner/eyepieces.freeman.html ], on a dark cloudless night [ http://antwrp.gsfc.nasa.gov/apod/ap000611.html ], you can see clusters of stars [ http://antwrp.gsfc.nasa.gov/apod/ap050406.html ], rings around Saturn [ http://antwrp.gsfc.nasa.gov/apod/ap040117.html ], glowing nebulas of gas [ http://antwrp.gsfc.nasa.gov/apod/ap041024.html ], craters on the Moon [ http://antwrp.gsfc.nasa.gov/apod/ap010809.html ], and galaxies across [ http://antwrp.gsfc.nasa.gov/apod/ap040718.html ] the universe. The technology to create this window -- and the secret sky it reveals -- was unknown only 400 years ago [ http://galileo.rice.edu/sci/lipperhey.html ]. Modern sky opportunities may occur this Saturday, Astronomy Day [ http://www.astroleague.org/al/astroday/adactiv05.html ], at local amateur astronomy clubs, universities, science centers, or planetariums. Pictured above [ http://homepage.univie.ac.at/peter.wienerroither/pwafox/deca01.htm ] is a small telescope being deployed at picturesque Hohe Wand, about 50 kilometers south of Vienna, Austria [ http://www.cia.gov/cia/publications/factbook/geos/au.html ]. The spin of the Earth [ http://antwrp.gsfc.nasa.gov/apod/ap010110.html ] is visible in the above photo as the long star trails [ http://antwrp.gsfc.nasa.gov/apod/ap040911.html ]. |
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Star Trails Over Vienna
| Title |
Star Trails Over Vienna |
| Explanation |
As the Earth spins on its axis, the sky seems to rotate around us. This motion, called diurnal motion [ http://antwrp.gsfc.nasa.gov/apod/ap010110.html ], produces the beautiful concentric trails traced by stars during time exposures. In the middle of the picture is the North Celestial Pole [ http://solar.physics.montana.edu/YPOP/Classroom/Lessons/Sundials/skydome.html ] (NCP), easily identified as the point in the sky at the center of all the star trail arcs. The star Polaris [ http://antwrp.gsfc.nasa.gov/apod/ap991006.html ], commonly known as the North Star [ http://en.wikipedia.org/wiki/North_star ], made the very short bright circle near the NCP. Full circle star trails are pictured over Vienna, Austria [ http://www.cia.gov/cia/publications/factbook/geos/au.html ]. This image [ http://homepage.univie.ac.at/peter.wienerroither/ pwafoxe.htm ], a relatively short exposure followed by a digital trick, could not have been taken during a single night because 24-hours are needed for one full rotation, and the Sun is sure [ http://antwrp.gsfc.nasa.gov/apod/ap050503.html ] to dominate the frame at some time. |
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Mir Dreams
| Title |
Mir Dreams |
| Explanation |
This dream [ http://www.pbs.org/wgbh/nova/mir/day.html ]-like image of Mir [ http://www.pbs.org/wgbh/nova/mir/tour.html ] was recorded by astronauts as the space shuttle orbiter Atlantis [ http://kids.msfc.nasa.gov/Rockets/ShuttleNames.asp ] approached the Russian space station prior to docking during the STS-76 mission in 1996. Sporting spindly appendages and solar panels, Mir resembles a whimsical flying insect hovering about 350 kilometers above New Zealand's [ http://www.rasnz.org.nz/index.htm ] South Island and the city of Nelson near Cook [ http://www.south-pole.com/p0000071.htm ] Strait. Mir was launched 20 years ago [ http://www.russianspaceweb.com/mir.html ] this week, and served as a continuously occupied orbital outpost [ http://spaceflight.nasa.gov/history/shuttle-mir/ ] until August 1999. Mir was visited by over 100 spacefarers from the nations of planet Earth including, Russia, the United States, Great Britain, Germany, France, Japan, Austria, Kazakhstan and Slovakia. The Mir was deorbited [ http://antwrp.gsfc.nasa.gov/apod/ap010323.html ] in March 2001. |
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Flooding along Danube River:
…
nasa, nasanaturalhazards
Heavy rains in Central and E
…
danube.TMO2002231
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-08-19 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
danube.TMO2002231 |
|
Flooding on Elbe River: Natu
…
nasa, nasanaturalhazards
Heavy rains in Central Europ
…
elbe.TMO2002230
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-08-19 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
elbe.TMO2002230 |
|
Flooding on Elbe River: Natu
…
nasa, nasanaturalhazards
Heavy rains in Central Europ
…
elbe.TMO2002230
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-08-19 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
elbe.TMO2002230 |
|
Flooding on Elbe River: Natu
…
nasa, nasanaturalhazards
Heavy rains in Central Europ
…
elbe.TMO2002232
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-08-20 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
elbe.TMO2002232 |
|
Flooding along Danube River:
…
nasa, nasanaturalhazards
Heavy rains in Central and E
…
danube.TMO2002230
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-08-19 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
danube.TMO2002230 |
|
Flooding along Danube River:
…
nasa, nasanaturalhazards
Heavy rains in Central and E
…
danube.TMO2002230
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-08-19 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
danube.TMO2002230 |
|
Floods in Central Europe: Na
…
nasa, nasanaturalhazards
* eoimages.gsfc.nasa.gov/ima
…
Austria_TMO_2006097
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2006-04-07 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Austria_TMO_2006097 |
|
Flooding on Elbe River: Natu
…
nasa, nasanaturalhazards
Heavy rains in Central Europ
…
elbe.L72002232
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-08-20 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
elbe.L72002232 |
|
Aerosols over Central and Ea
…
PIA04325
Sol (our sun)
Multi-angle Imaging SpectroR
…
| Title |
Aerosols over Central and Eastern Europe |
| Original Caption Released with Image |
Particulate air pollution is a complex mixture of particles of varying origins and compositions. Determining the type and abundance of tiny airborne particles, known as aerosols, is needed for monitoring air quality and for understanding climate change. During the last weeks of March 2003, unusually high and widespread aerosol pollution was detected over Europe by several satellite-borne instruments. The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard NASA's Terra satellite determines aerosol amount and information about particle properties by examining the variation in scene brightness at different view angles. These images and data products illustrate the amount of aerosols on two dates over parts of Central and Eastern Europe, from the Baltic Sea in the north to the Adriatic Sea in the south. Two groups of three panels are shown. Within each group, the left and center views are natural-color images from MISR's vertical-viewing (nadir) and most obliquely forward-viewing cameras, respectively, and the right-hand panel is a map of retrieved aerosol amount, parameterized by a quantity called the optical depth. A color scale is used to represent this quantity, and high aerosol amount is indicated by yellow or green pixels, and clearer skies are indicated by blue pixels. The left-hand group of panels is comprised of data acquired on February 23, 2003, when most of the land area was still partially frozen. The right-hand group of panels portrays the same area about one month later, on March 27. The nadir camera enables surface features to stand out most clearly, whereas MISR's oblique cameras enhance sensitivity to even thin layers of aerosols. In the March image, the only strong indications of haze from the nadir view are the thin tendrils of grayish pixels over the dark waters of the Baltic Sea. Although aerosols are conventionally difficult to discern over bright surfaces, MISR is able to produce an aerosol abundance map for both the earlier snow-covered scene and for the later date, though fewer successful retrievals were obtained in the winter data. Skies were relatively clear in the earlier view, and the high optical depths implied by the red pixels are probably blunders due either to the homogeneity of the underlying snow-covered surface or the presence of unscreened clouds. In contrast, the March data show a thick haze over most of the lower-elevation parts of the observed area. Optical depths are relatively lower over the Julian Alps and the mountains of western Croatia (just north of the Adriatic), whereas higher abundances are observed to the north of the mountains and over eastern Croatia. There is a gradual transition from higher optical depths in western Poland to lower optical depths in Lithuania and along the eastern coast of the Baltic. Higher optical depths are also indicated over much of Hungary, Slovakia and eastern Austria. Places where clouds or other factors precluded an aerosol retrieval are otherwise shown in, dark gray. An overview [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=8637 ] of the haze extent and meteorological conditions for March 28, 2003 is also available from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) sensor. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 16937 and 17403. The panels cover an area of about 380 kilometers x 1775 kilometers, and use data from blocks 43 to 55 within World Reference System-2 path 190. 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 ofTechnology. |
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