|
|
Oil Slicks
This is a radar image of an
…
10/26/95
| Date |
10/26/95 |
| Description |
This is a radar image of an offshore drilling field about 150 km (93 miles) west of Bombay, India, in the Arabian Sea. The dark streaks are extensive oil slicks surrounding many of the drilling platforms, which appear as bright white spots. Radar images are useful for detecting and measuring the extent of oil seepages on the ocean surface, from both natural and industrial sources. The long, thin streaks extending from many of the platforms are spreading across the sea surface, pushed by local winds. The larger dark patches are dispersed slicks that were likely discharged earlier than the longer streaks, when the winds were probably from a different direction. The dispersed oil will eventually spread out over the more dense water and become a layer which is a single molecule thick. Many forms of oil, both from biological and from petroleum sources, smooth out the ocean surface, causing the area to appear dark in radar images. There are also two forms of ocean waves shown in this image. The dominant group of large waves (upper center) are called internal waves. These waves are formed below the ocean surface at the boundary between layers of warm and cold water and they appear in the radar image because of the way they change the ocean surface. Ocean swells, which are waves generated by winds, are shown throughout the image but are most distinct in the blue area adjacent to the internal waves. Identification of waves provide oceanographers with information about the smaller scale dynamic processes of the ocean. This image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on October 9, 1994. The colors are assigned to different frequencies and polarizations of the radar as follows: Red is L-band vertically transmitted, vertically received, green is the average of L-band vertically transmitted, vertically received and C-band vertically transmitted, vertically received, blue is C-band vertically transmitted, vertically received. The image is located at 19.25 degrees north latitude and 71.34 degrees east longitude and covers an area 20 km by 45 km (12.4 miles by 27.9 miles). SIR- C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth. ##### |
|
Agricultural Fires in Northw
…
| Title |
Agricultural Fires in Northwest India |
| Description |
A tight cluster of red dots in the top left of this image marks the location of numerous actively burning fires at the foothills of the Himalaya Mountains in northwest India. The image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite on October 22, 2004, and also shows a thick haze dammed up at the base of the towering mountains at upper right. While smoke from the fires almost certainly contributed to the haze, there may also be residual dust from dust storms in the deserts of Afghanistan and Pakistan in previous weeks, as well as urban pollution from cities in Pakistan and India. The border between the two countries runs mostly along the eastern edge of the fertile Indus River floodplain, where vegetation stands out sharply against the paler, more arid terrain in the far left portion of the image. The Indus flows southward and empties into the Arabian Sea. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
|
Floods in Pakistan
| Title |
Floods in Pakistan |
| Description |
A dual disaster hit Pakistan in the final week of June 2007. On June 23, rare heavy rains and winds swept over much of the country, and three days later, on June 26, Cyclone Yemyin (03B) blew ashore in southern Pakistan. The two storms caused extensive flooding in the country's southwest from the Arabian Sea coast to the border with Afghanistan. The Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) captured this image of flooding near the Indus River on July 2, 2007. The large image shows additional flooding along the coast. In this type of false-color image, made with infrared and visible light, water is dark blue or black. The lighter blue color in the north is either water-soaked land or mud-laden water. The desert landscape is tan-pink, while cropland near the Indus is green. Clouds are pale blue and white. The lower image, taken on June 23 before the storm moved in, shows normal conditions. The white streak near the right edge of the image is sunlight reflected off the wetlands around the Indus River. In the area shown here, more than 100,000 people were displaced when 800 villages were submerged by floods, said Relief Web. [ http://www.reliefweb.int/rw/fullMaps_Sa.nsf/luFullMap/4B4253F15CBDB7D6C125730F003DC643/$File/rw_FL_pak070705.pdf?OpenElement ] As of July 4, the International Federation of Red Cross and Red Crescent Societies [ http://www.reliefweb.int/rw/RWB.NSF/db900SID/LSGZ-74SGLW?OpenDocument&rc=3&emid=FF-2007-000082-PAK ] estimated that approximately 300 lives had been lost throughout Pakistan, and 550,000 people had been displaced. You can download a 250-meter-resolution KMZ file of the flooding [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jul2007/pakistan_tmo_2007183.kmz ] and comparison imagery from June 23, 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. |
|
Haze along the Himalaya Fron
…
| Title |
Haze along the Himalaya Front Range |
| Description |
This Moderate Resolution Imaging Spectroradiometer (MODIS) image from the sensor on the Aqua satellite shows different types of aerosols (particles suspended in the atmosphere) over India and Pakistan on December 1, 2004. In the center of the image, the Indus River runs in a sinuous, thick green braid from the foothills of the Himalaya Mountains (top right, hidden by clouds) to the Arabian Sea (bottom left). Backed up against the mountains, a grayish pall is likely human-made particle pollution, from vehicles, energy production, and household heating and cooking fires. At the mouth of the Indus, a tan-colored cloud of aerosols is probably blowing dust from the region?s arid landscapes. To the west of the Indus, a rugged line of mountains separates Pakistan from Afghanistan. The large roan-colored desert is the Margo Desert of southern Afghanistan. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
|
Haze over Southwestern India
| Title |
Haze over Southwestern India |
| Description |
A plume of haze descended over Mumbai, India, on December 2, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard NASA's Aqua [ http://aqua.nasa.gov/ ] satellite took this picture the same day. In this image, the haze appears as a translucent band, slightly darker than the wispy clouds to the northwest. Underneath the haze, a greenish plume of sediment appears in the ocean off the coast of India. Although the origin of the plume was not clear from adjacent satellite imagery, it could have originated in India itself. Aerosolsminute particles suspended in the atmospherecan sometimes move in a gyre around India, following the path of the Ganges toward the Bay of Bengal, circling around the southern tip of the subcontinent, then re-approaching the country from the Arabian Sea. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of the Level 1 and Atmospheric Archive Distribution System. [ http://ladsweb.nascom.nasa.gov/ ] |
|
Heavy Rains Flood Pakistan
| Title |
Heavy Rains Flood Pakistan |
| Description |
Heavy rain and snow hammered Pakistan in the first two weeks of February 2005, leaving more than 300 people dead as a result of floods and avalanches throughout the country. More than 200 of the deaths occurred in southwestern Pakistan, where a week of rain taxed river and irrigation systems. This image, acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA?s Aqua [ http://aqua.nasa.gov/ ] satellite on February 11, 2005, shows streaks of blue-green floodwater all along the coast. The most deadly floods swept through the region around the coastal city of Pasni when an irrigation dam burst on February 10, washing away several villages and flooding the city with water. Pale blue lines trace out the contours of the flood water on the following day. The city itself is covered with a small cloud, but further evidence of flooding can be seen in the Arabian Sea to the south. Bright blue clouds of sediment fill the waters where floods washed dirt and debris into the sea. To the west, the Dasht River is dramatically flooded, having expanded from a thin green line that was barely visible on February 6 to a sprawling blue wetland. On the right side of the image, the entire coastline around Ormara has been inundated with water. If this scene were depicted in true color, as a human eye would see it, the mud-laden flood water would blend with the tan desert landscape. To make the flood water more visible, the image is in false color, with sediment-filled water represented in blue, while deeper ocean water is black. The bare or sparsely vegetated land has a pink tint, and the clouds are light blue. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
|
Heavy Rains Flood Pakistan
| Title |
Heavy Rains Flood Pakistan |
| Description |
Heavy rain and snow hammered Pakistan in the first two weeks of February 2005, leaving more than 300 people dead as a result of floods and avalanches throughout the country. More than 200 of the deaths occurred in southwestern Pakistan, where a week of rain taxed river and irrigation systems. This image, acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA?s Aqua [ http://aqua.nasa.gov/ ] satellite on February 11, 2005, shows streaks of blue-green floodwater all along the coast. The most deadly floods swept through the region around the coastal city of Pasni when an irrigation dam burst on February 10, washing away several villages and flooding the city with water. Pale blue lines trace out the contours of the flood water on the following day. The city itself is covered with a small cloud, but further evidence of flooding can be seen in the Arabian Sea to the south. Bright blue clouds of sediment fill the waters where floods washed dirt and debris into the sea. To the west, the Dasht River is dramatically flooded, having expanded from a thin green line that was barely visible on February 6 to a sprawling blue wetland. On the right side of the image, the entire coastline around Ormara has been inundated with water. If this scene were depicted in true color, as a human eye would see it, the mud-laden flood water would blend with the tan desert landscape. To make the flood water more visible, the image is in false color, with sediment-filled water represented in blue, while deeper ocean water is black. The bare or sparsely vegetated land has a pink tint, and the clouds are light blue. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
|
Dust Blowing off the Coast o
…
| Title |
Dust Blowing off the Coast of Pakistan |
| Description |
Intense heat can spawn dust storms, and Pakistan and India saw their share of heat and dust in the spring of 2006. A dust storm blew off the coasts of these countries and over the Arabian Sea on June 4, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard NASA's Terra [ http://terra.nasa.gov/ ] satellite took this picture the same day. The dust cloud shown in this image is thin enough to reveal the ocean and land surface below the dust. Along the coast of India, thick sediment has turned the water a brownish-green color, near the right edge of the image. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the Goddard Earth Sciences DAAC. [ http://daac.gsfc.nasa.gov/ ] |
|
Dust from Pakistan and Iran
| Title |
Dust from Pakistan and Iran |
| Description |
Winds blowing down from the Makran Coast Range in Western Pakistan (right) and Eastern Iran (left) are carrying dust over the Gulf of Oman and the Arabian Sea. Such wind patterns commonly blow dust from the coastal valleys into the water. This storm was recorded by the Moderate Resolution Imaging Spectroradiometer [ http://modis.gsfc.nasa.gov ] (MODIS) on the Aqua [ http://aqua.nasa.gov/ ] satellite on March 23, 2004. The horizontal stripes evident over the water mark the beginning and the end of the rotation of MODIS' double-sided scan mirror. The lines are caused by minute differences in the two sides of the scan mirror. The high-resolution image provided above is at MODIS' maximum resolution. The image is available in additional resolutions [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2004083-0323/Pakistan.A2004083.0855 ]. Image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
|
Dust from Southwest Asia ove
…
| Title |
Dust from Southwest Asia over Arabian Sea |
| Description |
On May 8, 2005, a veil of dust from the arid landscapes of southern Iran, Afghanistan, and Pakistan hung over the Arabian Sea. The S-shaped, olive green path of the Indus River in western Pakistan appears washed out beneath the dust. When this image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra [ http://terra.nasa.gov ] satellite, the wind was stirring dust from valley deserts and spreading it southward across the mountainous coastal terrain of Iran (which occupies most of the upper left of the scene) and Pakistan (which occupies most of the upper right). NASA image courtesy the MODIS Rapid Response Team, NASA-GSFC |
|
Dust from Southwest Asia ove
…
| Title |
Dust from Southwest Asia over Arabian Sea |
| Description |
On May 8, 2005, a veil of dust from the arid landscapes of southern Iran, Afghanistan, and Pakistan hung over the Arabian Sea. The S-shaped, olive green path of the Indus River in western Pakistan appears washed out beneath the dust. When this image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra [ http://terra.nasa.gov ] satellite, the wind was stirring dust from valley deserts and spreading it southward across the mountainous coastal terrain of Iran (which occupies most of the upper left of the scene) and Pakistan (which occupies most of the upper right). NASA image courtesy the MODIS Rapid Response Team, NASA-GSFC |
|
Dust in Afghanistan
| Title |
Dust in Afghanistan |
| Description |
Across a wide portion of southwestern Asia, winds were whipping across deserts, sending a froth of dust into the skies on April 8, 2005. The wind raised particularly thick streamers of dust from the surfaces of the Margo Desert in southern Afghanistan and the Thar Desert, which straddles the border between Pakistan and India. Like an atmospheric alter ego of the Indus River, an airborne river of dust flows southward from the Thar Desert and out over the Arabian Sea. This image of the event was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra [ http://terra.nasa.gov ] satellite. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the Goddard Earth Sciences DAAC. |
|
Dust in the Indus Valley
| Title |
Dust in the Indus Valley |
| Description |
From the foothills of the Himalaya Mountains (upper right) to the east of the broad swath of olive-green vegetation along the Indus River Plain, blowing dust and sand make their own river that flows past the Thar Desert and out over the Arabian Sea (lower left). The winds must be wide-spread and fierce over the region, as pale dust plumes are streaming away from orange-colored deserts in Afghanistan (upper left), as well. This image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite on May 23, 2004. Image by Jesse Allen, based on data from the MODIS Rapid Response Team, NASA-GSFC |
|
Dust off Iran and Pakistan
| Title |
Dust off Iran and Pakistan |
| Description |
Dust plumes blew off the coasts of Iran and Pakistan and over the Arabian Sea on January 4, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite captured this image the same day. Here, the dust plumes appear as pale beige wisps. One apparent source for the dust can be seen in Pakistan, perhaps 150 kilometers inland from the coast. South of the dust plumes, white clouds dot the sky. Aside from bands of greenish blueresulting from shallow water and/or sedimentalong the coast, the ocean appears dark blue. NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center |
|
Dust off Iran and Pakistan
| Title |
Dust off Iran and Pakistan |
| Description |
Dust plumes blew off the coasts of Iran and Pakistan on October 29, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite took this picture the same day. In this image, the pale beige plumes fan out over the deep blue Arabian Sea. The plumes appear thickest along the Iran-Pakistan border, and grow thinner to the east. The air over the land surface appears largely clear, implying that these dust plumes have arisen very near the coastline. Isolated clouds hover over the water in the south. NASA image courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. The Rapid Response Team provides daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?ArabianSea ] of this region. |
|
Dust off Pakistan
| Title |
Dust off Pakistan |
| Description |
Plumes of dust blew off the coasts of Pakistan and Iran on November 22, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite captured this image of the dust plumes blowing over the Arabian Sea the same day. In this image, the dust appears as elongated clouds of pale beige heading towards the southwest. The thickest plume blows off Pakistan, some 500 kilometers east of the border with Iran. Other plumes appear more transparent. As the plumes advance far enough off the coast, they appear to change direction, perhaps due to a weather system associated with the clouds in the south. NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center |
|
Dust off Pakistan
| Title |
Dust off Pakistan |
| Description |
Wisps of dust blew out of Pakistan over the Arabian Sea on December 20, 2006. The dust appears to be blowing off the light-colored coastline, but it could also have been transported from the north. Indeed, another dust storm clouds the skies over the desert north of the Siahan Range. The dust appears to be coming from a distinct point source in the Chagai Hills to the north. The large white area west of the desert is the Hamun-i-Mashkel, a dry wetland or lake. The loose, silty soils found in desiccated wetlands are often a source of dust, but that does not seem to be the case in this particular storm. This photo-like image was taken on December 20, 2006, by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite. Daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?ArabianSea ] of Pakistan are available from the MODIS Rapid Response Team. NASA image courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
|
Dust over Arabian Sea
| Title |
Dust over Arabian Sea |
| Description |
This true-color scene shows a heavy dust storm blowing along Pakistan?s southern coast and out over the Arabian Sea on December 14, 2003. The scene was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA?s Terra satellite. The MODIS sensor aboard NASA?s Aqua satellite also acquired this image [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2003348-1214/Pakistan2.A2003348.0920 ] over the same scene later that same day. Image courtesy Jacques Descloitres, MODIS Rapid Response Team at NASA GSFC |
|
Dust over Arabian Sea
| Title |
Dust over Arabian Sea |
| Description |
A dust storm was blowing large quantities of dust out over the Persian Gulf and Arabian Sea on Saturday, December 13, 2003. In this true-color scene, acquired by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), the dust storm (light brown pixels) can be seen extending from the the Arabian Peninsula (left) eastward over the Persian Gulf and the Gulf of Oman toward the Arabian Sea. Parts of southern Afghanistan and much of Pakistan are also covered by airborne dust. Further to the east, over northwestern India, there appears to be an extensive plume of another aerosol type. The grayish color of the haze there suggests it is of human origin. Image courtesy SeaWiFS Project, [ http://seawifs.gsfc.nasa.gov ] NASA/Goddard Space Flight Center, and ORBIMAGE |
|
Dust over Arabian Sea
| Title |
Dust over Arabian Sea |
| Description |
A massive dust storm on December 12, 2003, almost completely obscured large parts of southwest Asia at the time of this image, which was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite. Thick clouds of tan-colored dust wash over Iran (left), Afghanistan (top right), and Pakistan (bottom right). From Iran, the wave of dust is crashing over the Gulf of Oman, which opens into the Arabian Sea (bottom). The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at additional spatial resolutions, including MODIS? maximum resolution of 250 meters. Image courtesy Jacques Descloitres, MODIS Rapid Response Team at NASA GSFC |
|
Dust over the Arabian Sea
| Title |
Dust over the Arabian Sea |
| Description |
A number of jets of windblown desert dust (light brown plumes) were blowing over the Gulf of Oman (middle left) and the Arabian Sea (bottom center) on May 2, 2003. Originating from the Arabian Peninsula (left) as well as Iran, Afghanistan, and Pakistan (top center and top right, respectively), the dust obscures the surface over much of the region. This image was made using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors flying aboard NASA's Terra and Aqua satellites at hours apart on the same day. The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at MODIS' maximum spatial resolution of 250 meters. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Dust over the Arabian Sea
| Title |
Dust over the Arabian Sea |
| Description |
Dust blowing out of India, Pakistan, and Afghanistan mingled over the Arabian Sea on April 9, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite took this picture the same day. In this image, a beige plume of dust, shown near the left edge of the picture, pushes southward from Afghanistan, crossing over Pakistan toward the ocean. To the east, another dust plume over the border between India and Pakistan also heads toward the water. Two tendrils of dust merge over the water, just south of the coast. NASA imagery created by Jesse Allen, Earth Observatory, using data obtained courtesy of the Goddard Earth Sciences DAAC [ http://daac.gsfc.nasa.gov/ ]. |
|
Dust over the Arabian Sea
| Title |
Dust over the Arabian Sea |
| Description |
Dust blew over the Gulf of Oman and the Arabian Sea on July 15, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard NASA's Terra [ http://terra.nasa.gov/ ] satellite took this picture the same day. In this image, a thin layer of dust hangs in the air over the region, blending in with the clouds to the east. Although the dust is not particularly thick, it covers a large area. Summer heat contributes to dust storms by creating atmospheric conditions where even light winds can raise dust clouds. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team. |
|
Dust over the Arabian Sea
| Title |
Dust over the Arabian Sea |
| Description |
On February 10, 2007, a dust plume lingered over the Arabian Sea. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite took this picture the same day. This image shows the horseshoe-shaped dust plume hanging over the ocean, just east of the coast of Oman. Although the source of this dust plume is not immediately obvious, the dust likely blew off the coasts of Pakistan and Iran. A close examination of the high-resolution imagery reveals small tendrils of dust linking those coasts and the larger plume. NASA image by Jeff Schmaltz, MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center. |
|
Dust over the Arabian Sea
| Title |
Dust over the Arabian Sea |
| Description |
A dusty haze hung over the Arabian Peninsula, the Horn of Africa, and the Arabian Sea on June 30, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite took this picture the same day. The dust does not form a discernible plume. Rather, it lends a buff-colored tint to the scene, particularly around the Horn of Africa. Due east from there, dust mingles with clouds. The Arabian Peninsula and the Horn of Africa rank among the world's most prolific dust-producing regions. Dust activity typically increases when summertime Sun heats the desert surface and creates instability in the lowest layer of the atmosphere. This instability makes the lofting of dust particles into the air more likely. NASA image created by Jesse Allen, using data provided courtesy of the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team. |
|
Dust over the Arabian Sea
| Title |
Dust over the Arabian Sea |
| Description |
In early December 2002, strong winds were blowing dust and sand from the Makran Mountains in southern Pakistan and Iran out over the Arabian Sea. The above true-color image of the dust plumes was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, flying aboard NASA?s Aqua spacecraft. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Dust over the Arabian Sea
| Title |
Dust over the Arabian Sea |
| Description |
A number of jets of windblown desert dust (light brown plumes) were blowing over the Arabian Sea on March 2, 2003. Originating from the Arabian Peninsula (middle left) as well as Iran and Pakistan (top center and top right, respectively) the dust obscures the surface over much of the region. Notice the very thin line of clouds, much whiter and brighter than the dust, running southeastward over the Gulf of Oman and demarcating the edge of the front. Another similar cloud pattern can be seen south of Oman. Notice also the vertical discontinuity running from top to bottom through the center of this scene. This image was made using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors flying aboard NASA's Terra and Aqua satellites at hours apart on the same day. The scene appears a bit different to each satellite not only because the clouds and dust plumes are moving, but also because the relative angle of the sun is changing. In the righthand image (Aqua MODIS), you can discern more dark green structure in the Indian Ocean, indicating the presence of phytoplankton. The intense biological activity going on there is quite likely being enhanced by the influx of iron-rich desert dust settling into the waters there over recent days. The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at MODIS' maximum spatial resolution of 250 meters. Image courtesy Jacques Descloitres, MODIS Rapid Response Team, NASA GSFC |
|
Dust Over the Gulf of Aden
| Title |
Dust Over the Gulf of Aden |
| Description |
Dust from the Arabian Peninsula and a wake from Socotra Island may have collaborated to create dust streamers over the Arabian Sea in early September 2006. Wind passing over an island can create a wake, affecting atmospheric patterns downwind. Satellites have long observed such phenomena in clouds. [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=4487 ] On September 9, 2006, the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard NASA's Terra [ http://terra.nasa.gov/ ] satellite captured this image of what appears to be an island wake. Rather than affecting clouds, however, this wake appears to affect a dust plume. The Arabian Peninsula produces a substantial portion of Earth's dust storms, and the area likely supplied the dust captured in this image. Once caught in the island's wake, the dust produced two streamers running in a roughly parallel direction. NASA image created by Jesse Allen, Earth Observatory, using data provided by the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team. |
|
Dust Storm in Afghanistan an
…
| Title |
Dust Storm in Afghanistan and Pakistan |
| Description |
Dust hung over the deserts of southern Afghanistan and western Pakistan on September 16, 2004. The Sea-viewing Wide Field of View Sensor (SeaWiFS [ http://seawifs.gsfc.nasa.gov/SEAWIFS.html ]) captured this oblique view of the dust storm at 8:00 UTC, 1 p.m. in Karachi, Pakistan. To the right of the dust storm, a green ribbon of vegetation lines the Indus River as it runs down the length of Pakistan into the Arabian Sea. Image provided by the SeaWiFS [ http://seawifs.gsfc.nasa.gov/SEAWIFS.html ] Project, NASA/Goddard Space Flight Center, and ORBIMAGE |
|
Dust Storm in Pakistan
| Title |
Dust Storm in Pakistan |
| Description |
A large storm is blowing thick plumes of desert dust over the Arabian Sea. The dust is coming from the shores of Pakistan (right) and Iran (left). The pattern seen in this image is common. Winds often blow down from Makran Coast Range in Western Pakistan and Eastern Iran into the coastal valleys, and carry dust out over the Sea. This Moderate Resolution Imaging Spectroradiometer [ http://modis.gsfc.nasa.gov ] (MODIS) image was acquired by the Terra [ http://terra.nasa.gov/ ] satellite on November 24, 2003. The high resolution image provided above is at 500 meters per pixel. The image is also available in additional resolutions [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2003328-1124/Pakistan.A2003328.0640 ]. Image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
|
Dust Storm in Pakistan
| Title |
Dust Storm in Pakistan |
| Description |
Thick streamers of dust blew out of Pakistan on December 19, 2004. The dust storm appears to be originating near the base of the Chagai Hills near the border with Afghanistan and to the south in the hilly coastland between the Makran Coast Range and the Arabian Sea. This true-color image was acquired on December 19, 2004 by NASA?s Terra [ http://terra.nasa.gov/ ] satellite. The large image provided above has a resolution of 500 meters per pixel. The MODIS Rapid Response Team provides the image in additional resolutions. NASA image courtesy Jacques Descloitres, MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
|
Dust storm in the Indus Vall
…
| Title |
Dust storm in the Indus Valley |
| Description |
A large dust storm blew through the Indus Valley, along the border between Pakistan and India, on June 12, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard NASA's Aqua [ http://aqua.nasa.gov/ ] satellite captured this image the same day. In this picture, the dust heads toward the Himalaya Mountains in the top right corner of the image. In the lower-left corner of the image, sprays of clouds appear to blow in the same direction as the dust, away from the Arabian Sea and toward the northeast. Once the dust reaches the mountains, it changes direction and blows along their southern edge. NASA image created by Jesse Allen, Earth Observatory, using data provided by the Goddard Earth Sciences DAAC. [ http://daac.gsfc.nasa.gov/ ] |
|
Dust Storm over Afghanistan
…
| Title |
Dust Storm over Afghanistan and Pakistan |
| Description |
A white veil of dust had settled over the Gulf of Oman and the Arabian Sea on October 8, 2004, when the Sea-viewing Wide Field-of-view Sensor aboard the OrbView-2 satellite captured this image. The dust is blowing out of the dried Hamoun Wetlands in the Sistan Basin straddling the Afghanistan/Iran border. Most of the dust is trapped in southwestern Afghanistan and northern Pakistan by the Central Makran Mountains, though some has escaped through river valleys and is blowing over the sea. The verdant green strip running down the right edge of the image is formed by the Indus River and the agricultural land it supports. NASA images courtesy the SeaWiFS Project [ http://seawifs.gsfc.nasa.gov/SEAWIFS.html ], NASA/Goddard Space Flight Center, and ORBIMAGE [ http://www.orbimage.com/ ]. |
|
Dust Storm over Pakistan
| Title |
Dust Storm over Pakistan |
| Description |
A dust storm blew off the southern coasts of Pakistan and Iran, flowing out over the Arabian Sea on June 1, 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov/ ] flying onboard NASA's Aqua [ http://aqua.nasa.gov/ ] satellite took this picture the same day. In this image, the dust appears as pale beige swirls over the ocean water. The dust appears thickest in the east, south of Pakistan. To the east of the dust storm is some cloud cover. Dust storms often result from extremely hot, dry conditions, and they occur frequently in the Middle East. According to news reports, Pakistan suffered a severe heat wave in May 2006, and temperatures remained high at the beginning of June. NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team. |
|
Dust Storm over Southern Asi
…
| Title |
Dust Storm over Southern Asia |
| Description |
A new and massive dust storm (light brown) erupted out of the Sistan Basin straddling the border between Iran and Afghanistan on April 29, 2004. The dust blew southward and spread out over a wide area, covering most of southern Afghanistan and western Pakistan. (The borders between those countries are traced here in black.) The dust can be seen here extending well out over the Arabian Sea (bottom). For more than five millennia, the Sistan Basin served as a cradle for life in what was once a 2,000-square-km (800-square-mile) wetland ecosystem known as the Hamoun Wetlands. Fed mainly by the springtime meltwater running off the mountains to the north and coursing through the Helmand River, the Hamoun Wetlands were replenished every year so that for thousands of years the region was an abundant source of fish, game, and fresh water for farming. But with unprecedented population growth in the region throughout the 20th century, coupled with a relatively sudden and dramatic increase in irrigation off of the Helmand River, the Hamoun Wetlands have almost completely dried up within the last 5 years. What was once a lush ecosystem teeming with life has been replaced by a mostly lifeless salt pan. (For more details, please read From Wetland to Wasteland. [ http://earthobservatory.nasa.gov/Study/hamoun/ ]) The light, silty lakefloor is now vulnerable to the intense heat and strong winds often experienced in this region that, in recent years, have been generating some very impressive dust storms that appear to be increasing in both frequency and severity. This true-color image was captured on April 29, 2004, by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Aqua [ http://aqua.nasa.gov ] satellite. The high-resolution copy available here is 500 meters per pixel. Additional resolution [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2004120-0429/Pakistan.A2004120.0915 ] copies of this image are also available. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
|
Dust Sweeps across the Arabi
…
| Title |
Dust Sweeps across the Arabian Sea |
| Description |
Strong winds swept large plumes of dust (tan pixels) off the southern coasts of Iran and Pakistan south and eastward across the Arabian Sea on February 9, 2004. The black line running vertically through the top center of this scene shows the border between Iran and Pakistan, the easternmost tip of the Arabian Peninsula juts in to the left center of the image. This true-color image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA?s Terra satellite. Another image [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2004040-0209/ArabianSea2.A2004040.0915 ] was acquired a few hours later that same day by MODIS aboard the Aqua. The high-resolution image above is 500 meters per pixel, but both images are available at the sensor?s full resolution [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2004040-0209/ArabianSea.A2004040.0610 ] of 250 meters per pixel. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/ ] at NASA GSFC |
|
Phytoplankton Bloom in the A
…
| Title |
Phytoplankton Bloom in the Arabian Sea |
| Description |
If you followed the marine food chain to its last link, you would find phytoplankton. The microscopic marine plants that form the basis of ocean life depend on many variable factors to sustain their own existence. Like land-based plants, phytoplankton need sunlight and nutrients like iron, nitrate, and phosphate. The amount of phytoplankton that can grow in any section of ocean depends on the availability of these factors. In the Arabian Sea, phytoplankton thrives in a narrow window of time defined by seasonal monsoons. During the summer monsoon, strong winds blow from the southwest across the Arabian Sea. These winds stir ocean currents, allowing cold, nutrient-rich water to rush up from the bottom. The winds also carry minerals from the land onto the surface of the ocean. The added nutrients from both sources feed the tiny ocean plants. Though the summer monsoon provides nutrients to the plants, it also limits their growth by blocking sunlight. In June and July, thick, heavy clouds cover the ocean, lowering the amount of light that reaches the surface of the ocean. In August, the clouds typically clear, letting the life-giving light shine through. (To learn more, read "Illuminating Photosynthesis in the Arabian Sea." [ http://earthobservatory.nasa.gov/Study/ArabianSea/ ]) In October, the winds begin to reverse, and currents change so that fewer nutrients are available at the surface. It is in this August-to-October window when nutrients are still plentiful and sunlight is strong that phytoplankton grow most readily in the Arabian Sea. This year is no exception. On October 6, 2004, the Sea-viewing Wide Field-of-view Sensor aboard the OrbView-2 satellite captured the above images showing high concentrations of phytoplankton in the Arabian Sea. The chlorophyll that the plants use to convert light to food tints the water green in the natural color image (top). The phytoplankton are growing in large swirls that follow the eddies and currents of the surface water. In the lower image, ocean chlorophyll concentrations are shown. Not surprisingly, concentrations appear to be highest near the coast where upwelling makes nutrients more available. NASA images courtesy the SeaWiFS Project [ http://seawifs.gsfc.nasa.gov/SEAWIFS.html ], NASA/Goddard Space Flight Center, and ORBIMAGE [ http://www.orbimage.com/ ]. |
|
Phytoplankton in the Arabian
…
| Title |
Phytoplankton in the Arabian Sea |
| Description |
Ribbons and swirls of yellow trace out regions of high chlorophyll concentration in the Arabian Sea in this Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) image, taken by NASA?s Aqua [ http://aqua.nasa.gov/ ] satellite on February 22, 2005. High chlorophyll concentrations indicate that tiny ocean plants, called phytoplankton, are thriving near the ocean?s surface. The plants can both nourish and destroy a marine ecosystem. Phytoplankton are a major source of food for many marine animals. Regions that produce large amounts of phytoplankton also tend to support a thriving fish population. But when phytoplankton concentrations get to be too great, they can create ?dead zones? in the ocean?oxygen-poor regions where few, if any, fish can survive. Dead zones occur when phytoplankton die and begin to sink to the sea floor. Bacteria break down the plants, and if the concentration of decaying plants is high enough, the bacteria can consume all of the oxygen in the region. Satellite images such as this Aqua MODIS image help monitor phytoplankton concentrations in the world?s oceans. While high concentrations in this image do not necessarily point to dead zones, they can show where potential problems exist. Regions where no data exist because of cloud cover or other reasons are white, while land is grey. Some of the high chlorophyll concentrations seen here may be related to recent floods [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=12724 ] along the coast of Pakistan. Flood water sweeps minerals from the land into the ocean, providing iron and other nutrients for phytoplankton to grow. Wind-blown dust is another source of nutrients for phytoplankton, and MODIS observed dust storms over the Arabian Sea on February 19 [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?ArabianSea/2005050/ArabianSea.2005050.terra ] and February 17 [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?ArabianSea/2005048/ArabianSea.2005048.terra ]. These storms may have contributed to the growth of the phytoplankton. NASA image courtesy Norman Kuring, MODIS Ocean Color Team [ http://oceancolor.gsfc.nasa.gov/ ] |
|
Fires in Pakistan and India
| Title |
Fires in Pakistan and India |
| Description |
At the foothills of the Himalaya Mountains, the Indus River Valley spreads in a fertile swath toward the Arabian Sea across the deserts of Pakistan (left). In this Moderate Resolution Imaging Spectroradiometer (MODIS) image from April 25, 2004, actively burning fires have been detected by MODIS and marked in red. The widespread nature of the fires and the time of year suggest that these fires are being set intentionally for agricultural purposes. Though not necessarily hazardous, such large-scale burning can have a strong impact on weather, climate, human health, and natural resources. In this scene, smoke hangs over Pakistan and northwestern India. The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at additional resolutions. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA-GSFC |
|
Siachen Glacier
| Title |
Siachen Glacier |
| Description |
At an altitude of roughly 5,400 meters (17,700 feet), the Siachen Glacier in Kashmir is a forbidding place. Blizzards can last for weeks, temperatures can drop to -55 degrees Celsius (-67 degrees Fahrenheit), and crevasses can swallow a person whole. At much lower altitudes, the glacier's impact is benign: it is the source of the Nubra River, a tributary of the Indus River flowing into Pakistan and the Arabian Sea. Sometimes described as a white snake, the Siachen Glacier is more than 70 kilometers long. Lying inside a rock-strewn trough roughly 2 kilometers wide, the glacier is covered with snow in the middle. Landsat 7 took this picture on May 18, 2001. The glacier's central region is covered with snow, and that snow and the rest of the glacier's icy surface appear white. Glaciers can merge together like rivers, and that is the case here. Several tributary rivers of ice flow together, such as the Lolofond and Teram Shehr glaciers, adding their ice to the Siachen Glacier as it winds southeast, where the Nubra River emerges from its terminus. In the scene, snow and ice cover most of the jagged peaks of the Himalaya Mountains. At an altitude far too high to support a forest, the bare mountainous surfaces appear in varying shades of beige. India and Pakistan fought for control of this glacier starting in the 1980s. Long known as the world's highest battleground, the glacier could enjoy a different status. By early 2006, some diplomats discussed making the area a peace park. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the University of Maryland's Global Land Cover Facility. [ http://glcf.umiacs.umd.edu/index.shtml ] |
|
Fires in Southern India
| Title |
Fires in Southern India |
| Description |
Numerous scattered fires (red dots) were detected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite across southern India on January 31, 2003. Fire are especially concentrated in the Nallamala Hills region of the Eastern Ghats along India's Indian Ocean coast (right). Fires also drape down the Western Ghat Mountains on India's Arabian Sea coast (left). The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at MODIS' maximum spatial resolution of 250 meters. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Tropical Cyclone 03B
| Title |
Tropical Cyclone 03B |
| Description |
Cyclonic storms in the Arabian Sea are rare, but not unheard of. Two tropical cyclones in the space of a month, on the other hand, is quite rare indeed. Unlike its predecessor, Tropical Cyclone Gonu, [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14295 ] Cyclone 03B originated on the opposite side of the Indian Peninsula in the Bay of Bengal. At 11:10 a.m. local time (06:10 UTC) on June 25, 2007, when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured this image, Tropical Cyclone 03B was reforming in the Arabian Sea south of the Pakistan coast after having crossed over India. The storm system has a discernible spiraling shape, but does not appear well-formed in this image. The storm has no distinct eye, suggesting that it was not particularly well organized. At the time, sustained winds were measured at 60 kilometers per hour (40 miles per hour) according to the University of Hawaii's Tropical Storm Information Center. [ http://www.solar.ifa.hawaii.edu/Tropical/ ] The storm flooded India's Andhra Pradesh province, resulting in 45 deaths, according to Weather Underground. [ http://www.wunderground.com/ ] It also caused flooding and wind damage in Karachi, Pakistan, where the death toll was around 200, according to BBC News. [ http://news.bbc.co.uk/ ] After crossing land, the storm reached the Arabian Sea and began to reform. As of June 26, forecasts were calling for the storm to gain some organization and power, skirt the Pakistan coast, and make landfall again somewhere near the border between Iran and Pakistan. Storm surge from Cyclone 03B was predicted to be moderately high, even though the storm was not strong, since the offshore waters are shallow, similar to the northern Gulf of Mexico. Because these kinds of storms are rare in the area, coastal communities are particularly vulnerable to storm surge damage. You can download a 250-meter-resolution Cyclone 03B KMZ file [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jun2007/ cyc03b_tmo_2007158.kmz ] for use with Google Earth. [ http://earth.google.com/download-earth.html ] NASA image by Jesse Allen, using data provided courtesy of the MODIS Rapid Response team [ http://rapidfire.sci.gsfc.nasa.gov ] at Goddard Space Flight Center. |
|
Tropical Cyclone Gonu
| Title |
Tropical Cyclone Gonu |
| Description |
This data visualization shows Tropical Cyclone Gonu and its spiral pattern of winds as recorded by NASA's QuikSCAT [ http://winds.jpl.nasa.gov/missions/quikscat/index.cfm ] satellite on June 4, 2007. Varying wind speeds within the storm form a bull's-eye of color, with the highest wind speeds shown in purple in the center of the storm and gradually decreasing speeds radiating outward. Wind direction is depicted with small barbs. White barbs point to areas of heavy rain. You might expect to see such a well-developed storm hovering over the warm waters of the Caribbean or in the South Pacific, but Tropical Cyclone Gonu showed up in an unusual place. On June 4, 2007, when it was observed by the QuikSCAT satellite, Cyclone Gonu was approaching the northeastern shore of Oman, a region better known for hot desert conditions. Though rare, cyclones like Gonu are not unheard of in the northern Indian Ocean basin. Most cyclones that form in the region form over the Bay of Bengal, east of India. Those that take shape over the Arabian Sea, west of the Indian peninsula, tend to be small and fizzle out before coming ashore. Cyclone Gonu is a rare exception. As of June 4, 2007, the powerful storm had reached a dangerous Category 4 [ http://www.nhc.noaa.gov/aboutsshs.shtml ] status, and it was forecast to graze Oman's northeastern shore, following the coastline of the Gulf of Oman. According to storm statistics maintained on Unisys Weather, [ http://weather.unisys.com/hurricane/ ], the last storm of this size to form over the Arabian Sea was Cyclone 01A, which tracked northwest along the coast of India between May 21 and May 28, 2001. Unlike Gonu's forecasted track, Cyclone 01A's path never brought it ashore. Ground or aircraft-based measurements of the wind strength of Cyclone Gonu would likely show sustained winds significantly higher than those estimated by QuikSCAT. QuikSCAT uses a scatterometer, a device that sends pulses of microwave energy through the atmosphere to the ocean surface and measures the energy that bounces back from the wind-roughened surface. The energy of the microwave pulses changes depending on wind speed and direction, giving scientists a way to monitor wind around the world. This technique does not work over land, but allows measurements in storms over oceans. Wind speeds in trropical cyclones, however, are difficult for QuikSCAT to measure. To relate the radar signal the sensor measures to actual wind speed, scientists compare measurements taken from buoys and other ground stations to data the satellite acquired at the same time and place. Because the high wind speeds generated by cyclones are rare, scientists do not have enough corresponding ground information to know how to translate data from the satellite for wind speeds above 50 knots (about 93 km/hr, or 58 mph). Also, the unusually heavy rain found in a cyclone distorts the microwave pulses in a number of ways, making a conversion to accurate wind speed difficult. Instead, the scatterometer provides a nice picture of the relative wind speeds within the storm and shows wind direction. NASA image courtesy of David Long, Brigham Young University, on the QuikSCAT Science Team [ http://winds.jpl.nasa.gov/ ], and the Jet Propulsion Laboratory. |
|
Tropical Cyclone Gonu
| Title |
Tropical Cyclone Gonu |
| Description |
MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center., You might expect to see a storm with near-perfect symmetry and a well-defined eye hovering over the warm waters of the Caribbean or in the South Pacific, but Tropical Cyclone Gonu showed up in an unusual place. On June 4, 2007, when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite captured this image, Tropical Cyclone Gonu was approaching the northeastern shore of Oman, a region better known for hot desert conditions. Though rare, cyclones like Gonu are not unheard of in the northern Indian Ocean basin. Most cyclones that form in the region form over the Bay of Bengal, east of India. Those that take shape over the Arabian Sea, west of the Indian peninsula, tend to be small and fizzle out before coming ashore. Cyclone Gonu is a rare exception. As of June 4, 2007, the powerful storm had reached a dangerous Category 4 [ http://www.nhc.noaa.gov/aboutsshs.shtml ] status, and it was forecast to graze Oman's northeastern shore, following the Gulf of Oman. According to storm statistics maintained on Unisys Weather, [ http://weather.unisys.com/hurricane/ ] the last storm of this size to form over the Arabian Sea was Cyclone 01A, which tracked northwest along the coast of India between May 21 and May 28, 2001. Unlike Gonu's forecasted track, Cyclone 01A's path never brought it ashore. MODIS acquired this photo-like image at 12:00 p.m. local time (9:00 UTC), a few hours after the Joint Typhoon Warning Center [ https://metocph.nmci.navy.mil/jtwc.php ] estimated Gonu's sustained winds to be over 240 kilometers per hour (145 miles per hour). The satellite image confirms that Gonu was a super-powerful cyclone. The storm has the hallmark tightly wound arms that spiral around a well-defined, circular eye. The eye is surrounded by a clear wall of towering clouds that cast shadows on the surrounding clouds. Called hot towers, [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17662 ] these clouds are a sign of the powerful uplift that feeds the storm. The symmetrical spirals, clear eye, and towering clouds are all features regularly seen in satellite images of other particularly powerful cyclones, which are also known as typhoons or hurricanes when they form in other parts of the world. The high-resolution image provided above is at MODIS' full spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response System provides this image at additional resolutions. [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2007155-0604/Gonu.A2007155.0900 ] You can download a 250-meter-resolution Cyclone Gonu KMZ file [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jun2007/Gonu.A2007155.0900.250m.kmz ] for use with Google Earth. [ http://earth.google.com/download-earth.html ] NASA image by Jeff Schmaltz, |
|
Tropical Cyclone Gonu
| Title |
Tropical Cyclone Gonu |
| Description |
At one time, Cyclone Gonu was a powerful Category 5 storm packing sustained winds of 255 kilometers per hour (160 miles per hour), according to the Joint Typhoon Warning Center, [ https://metocph.nmci.navy.mil/jtwc.php ] and on a course towards Oman. This made it the most powerful cyclone ever to threaten the Arabian Peninsula since record keeping began back in 1945. Tropical cyclones do on occasion form in the Arabian Sea, but they rarely exceed tropical storm intensity. In 2006, Tropical Storm Mukda was the only system to form in the region, and it remained well out to sea before dissipating. Gonu became a tropical storm in the morning (local time) of June 2, 2007, in the east-central Arabian Sea. After some initial fluctuations in direction, the storm settled on a northwesterly track and began to intensify. Gonu went from tropical storm intensity to a Category 2 Tropical Cyclone [ http://www.nhc.noaa.gov/aboutsshs.shtml ] on the night of June 3. Overnight, it developed into a Category 4 storm with winds estimated at 210 km/hr (132 mph). The Tropical Rainfall Measuring Mission (TRMM) [ http://trmm.gsfc.nasa.gov/ ], captured this image of Gonu as the storm was moving northwest over the central Arabian Sea. The image was taken at 6:23 a.m. local time (03:23 UTC) on June 4, 2007, when Gonu was a Category 4 storm. It shows the horizontal distribution of rain intensity looking down on the storm. The distribution of rain within the storm reveals the storm's structure, and in this case, Gonu displays all of the tell-tale signs of a potent storm. Not only did Gonu have a complete, well-formed, symmetrical eye surrounded by an intense eyewall (innermost red ring), this inner eyewall was surrounded by a concentric outer eyewall (outermost red and green ring). This double eyewall structure only occurs in very intense storms. Eventually the outer eyewall will contract and replace the inner eyewall, a process known as eyewall replacement. The image was made with data from several sensors on the TRMM satellite. Rain rates in the center of the swath are from the TRMM Precipitation Radar, while those in the outer portion are from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner. Several hours after this image was taken, Gonu reached Category 5 intensity, the very peak of possible storm strengths. The system remained in this high state through the day, then began weakening during the night of June 4 as it continued to approach the coast of Oman. The center remained just offshore of the northeast coast of Oman as a Category 1 storm before turning northward towards Iran, where it was expected to make landfall as a tropical storm, according to forecasts made on June 6, 2007. The TRMM satellite was placed into service in November 1997. From its low-earth orbit, TRMM provides valuable images and information on storm systems around the tropics using a combination of passive microwave and active radar sensors, including the first precipitation radar in space. TRMM is a joint mission between NASA and the Japanese space agency, JAXA. NASA image produced by Hal Pierce (SSAI/NASA GSFC) and caption by Steve Lang (SSAI/NASA GSFC). |
|
Tropical Cyclone Gonu
| Title |
Tropical Cyclone Gonu |
| Description |
A storm with near-perfect symmetry and a well-defined eye hovering over the warm waters of the Caribbean or in the South Pacific is not unusual, but Tropical Cyclone Gonu showed up in a rather different place: the Arabian Sea. Though rare, cyclones like Gonu are not unheard of in the northern Indian Ocean basin. Most cyclones that form in the region form over the Bay of Bengal, east of India. Those that take shape over the Arabian Sea, west of the Indian peninsula, tend to be small and fizzle out before coming ashore. Cyclone Gonu was a rare exception. According to storm statistics maintained on Unisys Weather, [ http://weather.unisys.com/hurricane/ ] the last storm of this size to form over the Arabian Sea was Cyclone 01A, which tracked northwest along the coast of India between May 21 and May 28, 2001. Unlike Gonu's forecasted track, Cyclone 01A's path never brought it ashore. At 9:35 a.m. local time (06:35 UTC) on June 5, 2007, when the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite captured this image, Tropical Cyclone Gonu was approaching the northeastern shore of Oman. At this time, the powerful storm had reached a dangerous Category 4 [ http://www.nhc.noaa.gov/aboutsshs.shtml ] status. Sustained winds were measured at 250 kilometers per hour (155 miles per hour) according to the University of Hawaii's Tropical Storm Information Center, [ http://www.solar.ifa.hawaii.edu/Tropical/ ] at the time of this MODIS image. The storm has the hallmark tightly wound arms that spiral around a well-defined, circular eye. The eye is surrounded by a wall of towering clouds that cast shadows on the surrounding clouds. Called hot towers, [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17662 ], these clouds are a sign of the powerful uplift that feeds the storm. The symmetrical spirals, distinct eye, and towering clouds are all features regularly seen in satellite images of other particularly powerful cyclones, which are also known as typhoons or hurricanes when they form in other parts of the world. The forecast as of June 5 called for the storm to graze Oman's shore, but with the center of the storm staying offshore in the Gulf of Oman. The storm's first landfall was predicted to be in southern Iran. The cooler water along the Oman coast was expected to rob the storm of some of its intensity, and it was predicted to strike the Iranian coast at around Category 1 strength. If, however, the forecast track is not quite right and the storm stays farther from shore over shallower and much warmer waters in the Gulf of Oman, it could make landfall while still packing Category 3 winds. In either case, communities along the Gulf of Oman are poorly prepared for hurricanes, given their rarity, and severe damage to cities and oil platforms is possible due to winds and storm surge. The high-resolution image provided above is at MODIS' full spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response System provides this image at additional resolutions. [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2007156-0605/Gonu.A2007156.0635 ] You can download a 250-meter-resolution Cyclone Gonu KMZ file [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jun2007/Gonu.A2007156.0635.250m.kmz ] for use with Google Earth. [ http://earth.google.com/download-earth.html ] NASA image by Jeff Schmaltz, MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center. |
|
Flooding in Eastern India
| Title |
Flooding in Eastern India |
| Description |
Abutting the southern front of the snow-clad Himalaya Mountains, the broad, flat Ganges Plain is laced with rivers that transport glacial melt to the Bay of Bengal or the Arabian Sea. Not surprisingly, these rivers lead something of a Dr. JekyllMr. Hyde existence: during the dry winter, the rivers are small and sedate, their headwaters largely locked in ice. In the summer, temperatures in the mountains climb, melting mountain-top snow and fueling the Asian monsoon, and the rivers swell into roaring giants. Not every year is the same howeverthe monsoon may be wetter in a particular year or winter snows might be greater, leading to more snowmeltand 2007 numbered among the more extreme flood years. Heavy rain throughout July pushed the Ganges and its many tributaries over their banks, submerging large tracts of land in northeastern India. As of August 3, nearly 20 million people had been displaced in India, Bangladesh, and Nepal, and 125 had died in India, reported BBC News. [ http://news.bbc.co.uk/2/hi/south_asia/6927389.stm ] Among the most severely hit states was India's northeastern Bihar state. The Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) flying on NASA's Aqua [ http://aqua.nasa.gov/ ] satellite captured the top image of flooding on the Ganges and its tributaries on August 3, 2007. The lower image, captured by Aqua MODIS on June 4, 2007, shows the plain before the summer monsoon and snowmelt swelled the rivers. In these images (made with a combination of infrared and visible light), water is black or dark blue. Water takes on a brighter shade of blue when tinged with sediment. Clouds, pale blue and white, are scattered over the flooded region, which is bright green with vegetation. Sparsely vegetated areas or bare earth in the lower image are rose-tinted tan. On August 3, the Ganges, Gandak, and Kosi Rivers were so swollen that it was hard to see exactly where the rivers normally flow. The tributaries that feed the Kosi River, not even visible on June 4, have combined in a vast web of water-covered land. The light blue area under the clouds in the lower left corner of the image is probably water-soaked earth, not standing water. Though destructive, seasonal flooding in the Ganges River system blankets the plain with fertile alluvial soil, making it productive farmland. Because the plain is so fertile, it is one of the most densely populated regions on Earth.Daily images [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?FAS_India3/2007215 ] of northeastern India are available from the MODIS Rapid Response System in both false color, as shown here, and photo-like true color. NASA images courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
|
Flooding in southeastern Afr
…
| Title |
Flooding in southeastern Africa |
| Description |
Over the past three weeks, torrential wet season rains have fallen throughout parts of south-central Africa, including Zaire, Tanzania, Mozambique, Malawi, Madagascar and adjacent waters. This image shows a rainfall accumulation map obtained using NASA's Tropical Rainfall Measurement Mission (TRMM) satellite, combined with data from other rain measuring satellites. Three weeks of rain accumulation are shown, beginning on January 1, 2003. Rainfall accumulations approach two feet in some locations, leading to serious flooding and the displacement of many people from their homes. Many areas of the tropics endure a perpetual "drought-flood seesaw" over the years and this region of Africa is no exception. These rains, while helping to break a multiple year drought, have also seriously damaged this season's crops. The heavy rains are an extreme manifestation of the annual pattern of summer rainfall across the southern hemisphere, known as the Intertropical Convergence Zone (ITCZ). Over south central Africa, warm and humid air flowing off the Arabian Sea clashes with the hot, dry Harmattan (desert wind) blowing southward off northern Africa. Violent thunderstorm rains erupt within this atmospheric battle zone. The heavy rains shown in the image over Tanzania and neighboring countries were enhanced by mountainous terrain. The mountains force moisture-laden air from the ocean to ascend, producing more rain within clouds, then concentrate rain runoff into narrow valleys. Other extreme rainfall events from the past year can be seen on the TRMM website (trmm.gsfc.nasa.gov). *animations* ÿÿsmall (2.3 MB MPEG) ÿÿlarge [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jan2003/mozambique.qt ] (9 MB MPEG) Image courtesy of Hal Pierce, NASA Goddard Space Flight Center. |
|
Flooding in southeastern Afr
…
| Title |
Flooding in southeastern Africa |
| Description |
Over the past three weeks, torrential wet season rains have fallen throughout parts of south-central Africa, including Zaire, Tanzania, Mozambique, Malawi, Madagascar and adjacent waters. This image shows a rainfall accumulation map obtained using NASA's Tropical Rainfall Measurement Mission (TRMM) satellite, combined with data from other rain measuring satellites. Three weeks of rain accumulation are shown, beginning on January 1, 2003. Rainfall accumulations approach two feet in some locations, leading to serious flooding and the displacement of many people from their homes. Many areas of the tropics endure a perpetual "drought-flood seesaw" over the years and this region of Africa is no exception. These rains, while helping to break a multiple year drought, have also seriously damaged this season's crops. The heavy rains are an extreme manifestation of the annual pattern of summer rainfall across the southern hemisphere, known as the Intertropical Convergence Zone (ITCZ). Over south central Africa, warm and humid air flowing off the Arabian Sea clashes with the hot, dry Harmattan (desert wind) blowing southward off northern Africa. Violent thunderstorm rains erupt within this atmospheric battle zone. The heavy rains shown in the image over Tanzania and neighboring countries were enhanced by mountainous terrain. The mountains force moisture-laden air from the ocean to ascend, producing more rain within clouds, then concentrate rain runoff into narrow valleys. Other extreme rainfall events from the past year can be seen on the TRMM website (trmm.gsfc.nasa.gov). *animations* ÿÿsmall (2.3 MB MPEG) ÿÿlarge [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jan2003/mozambique.qt ] (9 MB MPEG) Image courtesy of Hal Pierce, NASA Goddard Space Flight Center. |
|
Dust off Iran and Pakistan:
…
nasa, nasanaturalhazards
Dust plumes blew off the coa
…
pakistan_amo_2007302
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-10-29 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
pakistan_amo_2007302 |
|
|
