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Chilly Temperatures During t
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| Title |
Chilly Temperatures During the Maunder Minimum |
| Description |
Many things can change temperatures on Earth: a volcano erupts, swathing the Earth with bright haze that blocks sunlight, and temperatures drop, greenhouse gases trap heat in the atmosphere, and temperatures climb. From 1650 to 1710, temperatures across much of the Northern Hemisphere plunged when the Sun entered a quiet phase now called the Maunder Minimum. During this period, very few sunspots appeared on the surface of the Sun, and the overall brightness of the Sun decreased slightly. Already in the midst of a colder-than-average period called the Little Ice Age, Europe and North America went into a deep freeze: alpine glaciers extended over valley farmland, sea ice crept south from the Arctic, and the famous canals in the Netherlands froze regularlyan event that is rare today. The impact of the solar minimum is clear in this image, which shows the temperature difference between 1680, a year at the center of the Maunder Minimum, and 1780, a year of normal solar activity, as calculated by a general circulation model. Deep blue across eastern and central North America and northern Eurasia illustrates where the drop in temperature was the greatest. Nearly all other land areas were also cooler in 1680, as indicated by the varying shades of blue. The few regions that appear to have been warmer in 1680 are Alaska and the eastern Pacific Ocean (left), the North Atlantic Ocean south of Greenland (left of center), and north of Iceland (top center). If energy from the Sun decreased only slightly, why did temperatures drop so severely in the Northern Hemisphere? Climate scientist Drew Shindell and colleagues at the NASA Goddard Institute for Space Studies tackled that question by combining temperature records gleaned from tree rings, ice cores, corals, and the few measurements recorded in the historical record, with an advanced computer model of the Earth's climate. The group first calculated the amount of energy coming from the Sun during the Maunder Minimum and entered the information into a general circulation model. The model is a mathematical representation of the way various Earth systemsocean surface temperatures, different layers of the atmosphere, energy reflected and absorbed from land, and so forthinteract to produce the climate. When the model started with the decreased solar energy and returned temperatures that matched the paleoclimate record, Shindell and his colleagues knew that the model was showing how the Maunder Minimum could have caused the extreme drop in temperatures. The model showed that the drop in temperature was related to ozone [ http://earthobservatory.nasa.gov/Library/Ozone/ozone_2.html ], in the stratosphere, the layer of the atmosphere that is between 10 and 50 kilometers from the Earth's surface. Ozone is created when high-energy ultraviolet light from the Sun interacts with oxygen. During the Maunder Minimum, the Sun emitted less strong ultraviolet light, and so less ozone formed. The decrease in ozone affected planetary waves, the giant wiggles in the jet stream that we are used to seeing on television weather reports. The change to the planetary waves kicked the North Atlantic Oscillation (NAO) [ http://earthobservatory.nasa.gov/Study/NAO_200307/NAO.html ]the balance between a permanent low-pressure system near Greenland and a permanent high-pressure system to its southinto a negative phase. When the NAO is negative, both pressure systems are relatively weak. Under these conditions, winter storms crossing the Atlantic generally head eastward toward Europe, which experiences a more severe winter. (When the NAO is positive, winter storms track farther north, making winters in Europe milder.) The model results, shown above, illustrate that the NAO was more negative on average during the Maunder Minimum, and Europe remained unusually cold. These results matched the paleoclimate record. By creating a model that could reproduce temperatures recorded in paleoclimate records, Shindell and colleagues reached a better understanding of how changes in the stratosphere influence weather patterns. With such an understanding, scientists are better poised to understand what factors could influence Earth's climate in the future. To read more about how ancient temperature records are used to improve climate models, see Paleoclimatology: Understanding the Past to Predict the Future, [ http://earthobservatory.nasa.gov/Study/Paleoclimatology_Understanding/paleoclimatology_understanding.html ] the final installment of a series of articles [ http://earthobservatory.nasa.gov/Study/Paleoclimatology/paleoclimatology_intro.html ] about paleoclimatology on the Earth Observatory. Map adapted from Shindell et al., 2001, copyright AAAS 2001. Terms and conditions of use for material copyright AAAS: Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modified, adapted, performed, displayed, published, or sold in whole or in part, without prior written permission from the publisher. |
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Grassfire in Iceland
| Title |
Grassfire in Iceland |
| Description |
At the end of March 2006, a grassfire broke out in western Iceland, perhaps as a result of a smoldering cigarette butt. Although this area near the coast to the northwest of the country's capital, Reykjavik, is typically very wet, a period of persistent north winds dried out the grass and made it flammable. The fire burned for several days, threatening farms and livestock and resulting in Iceland's largest fire in its recorded history. This image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) [ http://asterweb.jpl.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite was captured on April 6, 2006. The burned area appears as a large brownish-charcoal splotch in the center of the image. The fire started inland and burned all the way to the coast. This is a false-color image, and unburned vegetation appears red, clouds appear white, and the Atlantic Ocean (image left) appears nearly black. Several partially ice-covered lakes are scattered across the burned landscape, these lakes appear light blue. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team [ http://asterweb.jpl.nasa.gov ] |
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Dust Plumes off Iceland
| Title |
Dust Plumes off Iceland |
| Description |
Plumes of dust blew off the southern coast of Iceland in late June 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured this image on June 23, 2007. The dust appears as grayish blurs emanating from the coast southward over the North Atlantic Ocean. Blue-green algal blooms also fringe the coastline. Iceland's winter of 2006-2007 brought relatively light snow, leaving the local vegetation little shelter from frost. Both the vegetation and soil dried further in two weeks of arid weather prior to this dust storm. Strong winds from the north added the final ingredient needed for dust plumes in late June. You can download a 250-meter-resolution KMZ file of Iceland [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jul2007/iceland_tmo_2007174.kmz ] suitable for use with Google Earth. [ http://earth.google.com/ ] NASA image created by Jesse Allen, using data provided courtesy of the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team. Image interpretation by Ingibjörg Jónsdóttir, University of Iceland. |
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Dust Storm off Iceland
| Title |
Dust Storm off Iceland |
| Description |
A low-pressure system north of the United Kingdom was blowing dust off Iceland and sending it southward over the Atlantic Ocean on Oct. 5, 2004. The dust plume (light brown) is easily distinguished from the bright, white clouds in this true-color scene, acquired by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). NASA images courtesy the SeaWiFS Project [ http://seawifs.gsfc.nasa.gov/SEAWIFS.html ], Goddard Space Flight Center, and ORBIMAGE [ http://www.orbimage.com/ ] |
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Dust Storm Off Southern Coas
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| Title |
Dust Storm Off Southern Coast of Iceland |
| Description |
On May 11 and 12, 2002, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) observed a large plume of dust (brownish pixels) blown by stiff winds out from Iceland?s southern coast over the North Atlantic Ocean. This particular scene was acquired on May 12. In the large image (click on the image above), the low pressure cell that was driving the wind on that day is readily discernible to the southeast of the island. Image courtesy the SeaWiFS Project [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://seawifs.gsfc.nasa.gov/SEAWIFS.html ], NASA GSFC, and ORBIMAGE |
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Smoke Over Northern Europe a
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| Title |
Smoke Over Northern Europe and the Atlantic |
| Description |
Although skies may have been mostly cloud-free over Ireland and the United Kingdom on May 10, 2006, a pall of haze dimmed the day. The white haze drifts from the Atlantic Ocean northwest of Ireland, over the island country, and southeast over the Celtic Sea and the English Channel in this photo-like image taken by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite. The smoke is coming from hundreds of fires [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=13539 ] burning in western Russia, most of which are probably agricultural fires. The fires have been burning since late April, and in that time, the smoke has drifted northwest over Scandinavia, the Norwegian Sea, Iceland, and the Atlantic Ocean before curving south to blanket Ireland. Unrelated to the smoke, the ocean southwest of Ireland is brilliant green-blue where a large phytoplankton bloom is growing. Phytoplankton are microscopic plants that grow in the sun-lit surface waters of the ocean. When large colonies develop, the blooms are visible from space by the bright color they lend the normally dark water. The large image provided above has a resolution of 250 meters per pixel. The image is available in additional resolutions [ http://rapidfire.sci.gsfc.nasa.gov/subsets/subsets.php?Europe.2006130.aqua.2km ] from the MODIS Rapid Response Team. NASA image courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
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Flooding in Iceland
| Title |
Flooding in Iceland |
| Description |
Most spring floods are triggered by rain or melting snow, but when the Skafta River of southern Iceland flooded in late April 2006, geologic activity may have been the driver. The river flows out from under the Vatnajokull Ice Cap, a large permanent field of snow and ice that covers more than 8,000 square kilometers of southeastern Iceland, including a number of volcanoes and other regions of geothermal activity. Over these hotspots, the lower layer of the ice cap melts to form glacier lakes, some of which drain into the Atlantic Ocean through rivers such as the Skafta. Other lakes are dammed by walls of ice from the overlying glacier. Catastrophic floods can occur when water breaks through the ice dams and bursts into the rivers, or when geologic activity increases and melts more water. On April 22, 2006, floods swamped the Skafta River. The flood water was accompanied by dangerously high levels of sulfur, possibly from increased geologic activity, prompting the Civil Protection Department to issue a warning, said local news reports. In flood, the fast-moving river swept over the dark, volcanic soil west of the ice cap, and carried it into the ocean. The ocean was milky green with sediment when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite captured this image on April 27. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team. |
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Dust Plumes off Iceland: Nat
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nasa, nasanaturalhazards
Plumes of dust blew off the
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iceland_tmo_2007174
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-06-23 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
iceland_tmo_2007174 |
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Dust Storm Off Southern Coas
…
nasa, nasanaturalhazards
On May 11 and 12, 2002, the
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IcelandDust_S2002132
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-05-12 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
IcelandDust_S2002132 |
|
Dust Storm off Iceland: Natu
…
nasa, nasanaturalhazards
A low-pressure system north
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Iceland_OSE2004279
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2004-10-05 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Iceland_OSE2004279 |
|
The Land of Ice and Fire : I
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nasa, nasaimageofthedaygalle
…
Due to an unusual combinatio
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iceland_misr_med
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2001-08-16 |
| creator |
NASA -- Image courtesy NASA/GSFC/LaRC/JPL, MISR Team |
| identifier |
iceland_misr_med |
|
The Land of Ice and Fire : I
…
nasa, nasaimageofthedaygalle
…
Due to an unusual combinatio
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iceland_misr_med
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2001-08-16 |
| creator |
NASA -- Image courtesy NASA/GSFC/LaRC/JPL, MISR Team |
| identifier |
iceland_misr_med |
|
Grassfire in Iceland: Natura
…
nasa, nasanaturalhazards
At the end of March 2006, a
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ge_16352
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2006-04-06 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
ge_16352 |
|
Grassfire in Iceland: Natura
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nasa, nasanaturalhazards
At the end of March 2006, a
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ge_16352
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2006-04-06 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
ge_16352 |
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Chilly Temperatures During t
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nasa, nasaimageofthedaygalle
…
Many things can change tempe
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maunder_minimum_temperature
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2006-08-10 |
| creator |
NASA -- Map adapted from Shindell et al., 2001, copyright AAAS 2001. Terms and conditions of use for material copyright AAAS: Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modified, adapted, performed, displayed, published, or sold in whole or in part, without prior written permission from the publisher. |
| identifier |
maunder_minimum_temperature |
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Flooding in Iceland: Natural
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nasa, nasanaturalhazards
Most spring floods are trigg
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iceland_amo_2006117
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2006-04-27 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
iceland_amo_2006117 |
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Iceland: Image of the Day
nasa, nasaimageofthedaygalle
…
True to its name, Iceland is
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image02022004
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2004-01-28 |
| creator |
NASA -- Image courtesy Jeff Schmaltz, rapidfire.sci.gsfc.nasa.gov/ MODIS Land Rapid Response Team at NASA GSFC |
| identifier |
image02022004 |
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Smoke Over Northern Europe a
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nasa, nasanaturalhazards
Although skies may have been
…
Ireland_AMO_2006130
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2006-05-10 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Ireland_AMO_2006130 |
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The Land of Ice and Fire
PIA03426
Sol (our sun)
Multi-angle Imaging SpectroR
…
| Title |
The Land of Ice and Fire |
| Original Caption Released with Image |
. Each image represents an area of about 200 by 340 kilometers. Two of Iceland's larger icecaps, Langjökull (located just below image center) and Hofsjökull (just above center) can be clearly seen. The western edge of Vatnajökull is also visible at the top of the image, and a portion of Myrdalsjökull can be seen through the clouds in the upper right. Langjökull (the Long Glacier, 1287 meters maximum elevation)is the second largest icecap in Iceland. It supplies water to Lake Pingvallavatn, the largest lake in the country (visible in the lower right), and to several other lakes and geothermal areas. Hofsjökull (the Temple Glacier, 1760 meters) is the third largest icecap in Iceland. The landscape under the ice is the great mountain mass if of a central subglacial volcano. The brighter, rounded area atop the icecap is a vast, ice filled caldera. The Pjórsá, Iceland's longest and largest river, is fed by the Hofsjökull icecap. The river can be seen running adjacent to the icecap toward the Atlantic Ocean at image right. Iceland has a very vigorous climate, and the high-energy coastline and glacial melt waters result in the movement of a large amount of sediment to the sea, visible herein the turbid waters of the Pjórsá. The capital city of Reykjavík is visible in the lower right as a greyish region along the coast, to the west of (below) a bank of cumulus clouds. Reykjavík is located about 20 kilometers west of the Reykjanes-Langjökull volcanic zone, and the name of the city, the "Bay of Smokes", is testimony to the region's geothermal activity. 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., Due to an unusual combination of tectonic settings, many icecaps and glaciers of Iceland rest above active volcanoes. This landnation is located on the northern edge of the Mid-Atlantic ridge, at the intersection of the North American and Eurasian plates, and is one of the few places on Earth where a mid-ocean ridge is exposed above sea level. The land is built from erupted and intruded magmas concentrated around a hot spot beneath the spreading ridge. These late summer views of central and southwestern Iceland were obtained by the Multi-angle Imaging SpectroRadiometer on August 16,2001, during Terra orbit 8842. The upper image is a true-color view from the instrument's vertical-viewing (nadir) camera. The lower image is a stereo anaglyph generated from the instrument's nadir and 60-degree forward-viewing cameras. Viewing the anaglyph in 3-D requires the use of red/blue glasses with the red filter placed over your left eye. The images have been oriented with north at the left in order to facilitate stereo viewing. Information on ordering glasses is available here [ http://photojournal.jpl.nasa.gov/Help/VendorList.html#Glasses ] |
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A Vortex Street in the Arcti
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PIA03448
Sol (our sun)
Multi-angle Imaging SpectroR
…
| Title |
A Vortex Street in the Arctic |
| Original Caption Released with Image |
Marine stratocumulus clouds frequently form parallel rows, or "cloud streets", along the direction of wind flow. When the flow is interrupted by an obstacle such as an island, a series of organized eddies can appear within the cloud layer downwind of the obstacle. These turbulence patterns are known as von Karman vortex streets. In these images from NASA's Multi-angle Imaging SpectroRadiometer, an impressive vortex pattern continues for over three hundred kilometers southward of Jan Mayen island. Jan Mayen is an isolated territory of Norway, located about 650 kilometers northeast of Iceland in the north Atlantic Ocean. Jan Mayen's Beerenberg volcano rises about 2.2 kilometers above the ocean surface, providing a significant impediment to wind flow. These MISR images were captured on June 6, 2001, during Terra orbit 7808. The entire vortex street can be seen in the top panel, which is a natural-color view from the instrument's nadir (downward-looking) camera. The area covered measures 365 kilometers x 158 kilometers, and a cloud-clearing effect is apparent at the vortex centers until finally closing on the sixteenth"hole." The bottom panel is a stereo anaglyph of a portion of the vortex street, compiled using data from MISR's 26-degree forward and 70-degree backward viewing cameras. This view covers an area of about 183 kilometers x 96 kilometers. Despite the vertical exaggeration afforded by using widely separated angles, the relatively modest height variation in the cloud layer implies a vertically stable atmosphere. To facilitate stereo viewing, the images have been oriented with north at the left. Red/blue glasses should be used with the red filter placed over your left eye. Information on ordering glasses can be found here [ http://photojournal.jpl.nasa.gov/Help/VendorList.html#Glasses ]. Fluid dynamicist Theodore von Karman was the first to derive the conditions under which these turbulence patterns occur. Von Karman was a professor of aeronautics at the California Institute of Technology and one of the principal founders of NASA's Jet Propulsion Laboratory. 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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