Narrow Search
 
 
Advanced Search

Browse All : Images of Venezuela and Jet Propulsion Laboratory (JPL)

Printer Friendly
1-13 of 13
     
     
Hurricane Dean
Title Hurricane Dean
Description Hurricane Dean was the first hurricane of the 2007 Atlantic Hurricane Season. The storm system formed off the coast of South America on August 13. It traveled west, building strength from the warm waters as it headed towards the South American coast and the southern arc of the Caribbean Islands. By August 17, it had grown in power to become a Category 3 hurricane, [ http://www.nhc.noaa.gov/aboutsshs.shtml ] and forecasters were calling for it to potentially gain yet more strength as it passed over the warm waters of the Caribbean Sea. Dean was projected to cause major damage. Mexican authorities, according to news sources, were warning residents in the Yucatan Peninsula of the danger of the coming storm, which was projected to strike the peninsula. The storm might also brush against the islands of Hispaniola, Jamaica, and Cuba among others. Some forecasters were concerned about the possibility of Dean developing into super storm in the Gulf of Mexico, where storm surge and waves as well as winds might pose significant dangers to the oil and gas platforms. This data visualization of the hurricane shows observations from the QuikSCAT satellite on August 16, 2007, at 6:55 p.m. local time (21:55 UTC). At this time, Dean was poised to cross the Windward Islands of the Caribbean, while grazing the coast of Venezuela on the South American mainland. Peak winds were around 160 kilometers per hour (100 miles per hour, 85 knots) at this time, according to Unisys Weather's Hurricane information page, [ http://weather.unisys.com/hurricane/ ] making Dean a Category 2 hurricane. The image depicts wind speed in color and wind direction with small barbs. White barbs point to areas of heavy rain. QuikSCAT measurements of the wind strength of Hurricane Dean and other tropical cyclones can be slower than actual wind speeds. QuikSCAT's scatterometer 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. To relate the radar signal 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 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 exact 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.
Oil Slicks on Lake Maracaibo …
Title Oil Slicks on Lake Maracaibo, Venezuela
Description browse image of orbit 16081 (310 KB JPEG) Several oil slicks occurred on Lake Maracaibo in northwestern Venezuela between December 2002 and January 2003, and were observed by various satellite instruments. These images from the Multi-angle Imaging SpectroRadiometer (MISR) provide new information relating to one such event near the center of Lake Maracaibo on December 26, 2002. In unpolluted areas, the water surface is "ruffled" by wind and the resulting wave facets divert reflected rays into many directions. An oil film dampens the presence of small wind-driven "capillary" waves, resulting a smoother, more mirror-like surface. Also, oil is more strongly absorbing than the surrounding water. Therefore, at most viewing angles, a surface slick will appear darker than the surrounding unpolluted areas, whereas near the specular angle (the angle at which a perfect mirror reflects light) it will appear brighter. Simultaneous observation at multiple view angles therefore enhances the reliability of oil-slick detection using optical imaging. An example of how the optical contrast of an oil film on a water surface changes as a function of viewing angle is illustrated by these false-color MISR images, comprised of near-infrared, red and blue spectral data at three different angles, using the vertical-viewing camera (left), the 26ø-forward-viewing camera (center) and the 46ø-forward-viewing camera (right). A swirly area in the middle of the lake appears darker than the surrounding waters at both the nadir and 46° views, but brighter than the surrounding waters at the 26° view. Of the three images, only the 26° camera observes close to specular reflection angle. Lake Maracaibo is the largest lake in South America. The lake is somewhat saline, since it is connected to the Gulf of Venezuela by a narrow strait in the north. Venezuela is the largest oil producing nation in the Western Hemisphere, and the Lake Maracaibo basin includes the largest oil fields and almost a quarter of this nation's population. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. The MISR Browse Image Viewer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://eosweb.larc.nasa.gov/MISRBR/ ] provides access to low-resolution true-color versions of these images. These data products were generated from a portion of the imagery acquired during Terra orbit 16081. The panels cover an area of 72 kilometers x 225 kilometers. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://www-misr.jpl.nasa.gov/ ] Text by Clare Averill (Acro Service Corporation/JPL)
Oil Slicks on Lake Maracaibo …
Title Oil Slicks on Lake Maracaibo, Venezuela
Description browse image of orbit 16081 (310 KB JPEG) Several oil slicks occurred on Lake Maracaibo in northwestern Venezuela between December 2002 and January 2003, and were observed by various satellite instruments. These images from the Multi-angle Imaging SpectroRadiometer (MISR) provide new information relating to one such event near the center of Lake Maracaibo on December 26, 2002. In unpolluted areas, the water surface is "ruffled" by wind and the resulting wave facets divert reflected rays into many directions. An oil film dampens the presence of small wind-driven "capillary" waves, resulting a smoother, more mirror-like surface. Also, oil is more strongly absorbing than the surrounding water. Therefore, at most viewing angles, a surface slick will appear darker than the surrounding unpolluted areas, whereas near the specular angle (the angle at which a perfect mirror reflects light) it will appear brighter. Simultaneous observation at multiple view angles therefore enhances the reliability of oil-slick detection using optical imaging. An example of how the optical contrast of an oil film on a water surface changes as a function of viewing angle is illustrated by these false-color MISR images, comprised of near-infrared, red and blue spectral data at three different angles, using the vertical-viewing camera (left), the 26ø-forward-viewing camera (center) and the 46ø-forward-viewing camera (right). A swirly area in the middle of the lake appears darker than the surrounding waters at both the nadir and 46° views, but brighter than the surrounding waters at the 26° view. Of the three images, only the 26° camera observes close to specular reflection angle. Lake Maracaibo is the largest lake in South America. The lake is somewhat saline, since it is connected to the Gulf of Venezuela by a narrow strait in the north. Venezuela is the largest oil producing nation in the Western Hemisphere, and the Lake Maracaibo basin includes the largest oil fields and almost a quarter of this nation's population. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. The MISR Browse Image Viewer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://eosweb.larc.nasa.gov/MISRBR/ ] provides access to low-resolution true-color versions of these images. These data products were generated from a portion of the imagery acquired during Terra orbit 16081. The panels cover an area of 72 kilometers x 225 kilometers. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://www-misr.jpl.nasa.gov/ ] Text by Clare Averill (Acro Service Corporation/JPL)
Hurricane Dean: Natural Haza …
nasa, nasanaturalhazards
Hurricane Dean was the first …
dean_qsc_2007228
mediatype IMAGE
mediatype image
date 2007-08-16
creator NASA -- NASA Image Of The Day
identifier dean_qsc_2007228
Guiana Highlands, Shaded Rel …
PIA03396
Sol (our sun)
C-Band Interferometric Radar
Title Guiana Highlands, Shaded Relief and Colored Height
Original Caption Released with Image These two images show exactly the same area in South America, the Guiana Highlands straddling the borders of Venezuela, Guyana and Brazil. The image on the left was created using the best global topographic data set previously available, the U.S. Geological Survey's GTOPO30. In contrast, the image on the right was generated with a new data set recently released by the Shuttle Radar Topography Mission (SRTM) called SRTM30, which represents a significant improvement in our knowledge of the topography of much of the world. GTOPO30, with a resolution of about 928 meters (1496 feet), was developed over a three-year period and published in 1996, and since then has been the primary source of digital elevation data for scientists and analysts involved in global studies. However, since it was compiled from a number of different map sources with varying attributes, the data for some parts of the globe were inconsistent or of low quality. The SRTM data, on the other hand, were collected within a ten-day period using the same instrument in a uniform fashion, and were processed into elevation data using consistent processing techniques. Thus SRTM30 provides a new resource of uniform quality for all parts of the Earth, and since the data, which have an intrinsic resolution of about 30 meters, were averaged and resampled to match the GTOPO30 sample spacing and format, and can be used by the same computer software without modification. The Guiana Highlands are part of the Guyana Shield, which lies in northeast South America and represent one of the oldest land surfaces in the world. Chemical weathering over many millions of years has created a landscape of flat-topped table mountains with dramatic, steep cliffs with a large number of spectacular waterfalls. For example Angel Falls, at 979 meters the highest waterfall in the world, plunges from Auyan Tebuy, part of a mesa of the type that may have been the inspiration for Arthur Conan Doyle's 1912 best-seller "The Lost World." Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking, and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C. Location: 0.2 South to 8.7 degrees North latitude, 60 to 67.9 degrees West longitude Orientation: North toward the top Image Data: shaded and colored SRTM30 and GTOPO30 elevation models Data Resolution: SRTM 30 arcsecond (about 928 meters or 1496 feet) Date Acquired: February 2000 for SRTM
Guiana Highlands, Shaded Rel …
PIA03396
Sol (our sun)
C-Band Interferometric Radar
Title Guiana Highlands, Shaded Relief and Colored Height
Original Caption Released with Image These two images show exactly the same area in South America, the Guiana Highlands straddling the borders of Venezuela, Guyana and Brazil. The image on the left was created using the best global topographic data set previously available, the U.S. Geological Survey's GTOPO30. In contrast, the image on the right was generated with a new data set recently released by the Shuttle Radar Topography Mission (SRTM) called SRTM30, which represents a significant improvement in our knowledge of the topography of much of the world. GTOPO30, with a resolution of about 928 meters (1496 feet), was developed over a three-year period and published in 1996, and since then has been the primary source of digital elevation data for scientists and analysts involved in global studies. However, since it was compiled from a number of different map sources with varying attributes, the data for some parts of the globe were inconsistent or of low quality. The SRTM data, on the other hand, were collected within a ten-day period using the same instrument in a uniform fashion, and were processed into elevation data using consistent processing techniques. Thus SRTM30 provides a new resource of uniform quality for all parts of the Earth, and since the data, which have an intrinsic resolution of about 30 meters, were averaged and resampled to match the GTOPO30 sample spacing and format, and can be used by the same computer software without modification. The Guiana Highlands are part of the Guyana Shield, which lies in northeast South America and represent one of the oldest land surfaces in the world. Chemical weathering over many millions of years has created a landscape of flat-topped table mountains with dramatic, steep cliffs with a large number of spectacular waterfalls. For example Angel Falls, at 979 meters the highest waterfall in the world, plunges from Auyan Tebuy, part of a mesa of the type that may have been the inspiration for Arthur Conan Doyle's 1912 best-seller "The Lost World." Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking, and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C. Location: 0.2 South to 8.7 degrees North latitude, 60 to 67.9 degrees West longitude Orientation: North toward the top Image Data: shaded and colored SRTM30 and GTOPO30 elevation models Data Resolution: SRTM 30 arcsecond (about 928 meters or 1496 feet) Date Acquired: February 2000 for SRTM
Oil Slicks on Lake Maracaibo …
PIA04331
Sol (our sun)
Multi-angle Imaging SpectroR …
Title Oil Slicks on Lake Maracaibo, Venezuela
Original Caption Released with Image Several oil slicks occurred on Lake Maracaibo in northwestern Venezuela between December 2002 and January 2003, and were observed by various satellite instruments. These images from the Multi-angle Imaging SpectroRadiometer (MISR) provide new information relating to one such event near the center of Lake Maracaibo on December 26, 2002. In unpolluted areas, the water surface is "ruffled" by wind and the resulting wave facets divert reflected rays into many directions. An oil film dampens the presence of small wind-driven "capillary" waves, resulting a smoother, more mirror-like surface. Also, oil is more strongly absorbing than the surrounding water. Therefore, at most viewing angles, a surface slick will appear darker than the surrounding unpolluted areas, whereas near the specular angle (the angle at which a perfect mirror reflects light) it will appear brighter. Simultaneous observation at multiple view angles therefore enhances the reliability of oil-slick detection using optical imaging. An example of how the optical contrast of an oil film on a water surface changes as a function of viewing angle is illustrated by these false-color MISR images, comprised of near-infrared, red and blue spectral data at three different angles, using the vertical-viewing camera (left), the 26°-forward-viewing camera (center) and the 46°-forward-viewing camera (right). A swirly area in the middle of the lake appears darker than the surrounding waters at both the nadir and 46° views, but brighter than the surrounding waters at the 26° view. Of the three images, only the 26° camera observes close to specular reflection angle. Lake Maracaibo is the largest lake in South America. The lake is somewhat saline, since it is connected to the Gulf of Venezuela by a narrow strait in the north. Venezuela is the largest oil producing nation in the Western Hemisphere, and the Lake Maracaibo basin includes the largest oil fields and almost a quarter of this nation's population. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 16081. The panels cover an area of 72 kilometers x 225 kilometers, and utilize data from blocks 81 to 83 within World Reference System-2 path 8. 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.
Flooding Resulting From Hurr …
PIA00365
Sol (our sun)
Atmospheric Infrared Sounder …
Title Flooding Resulting From Hurricane Isidore, Comparing Data from September 12 and 28, 2002
Original Caption Released with Image Extent of Flooding due to Hurricane Isidore revealed in images from the Atmospheric Infrared Sounding System (AIRS) on Aqua Tropical Storm Isidore was born in mid-September north of Venezuela. It subsequently hit Mexico's Yucatan Peninsula as a Category 3 hurricane and came ashore near New Orleans on September 26th packing winds just below hurricane strength. Around the time of September 27, the storm was downgraded to a tropical depression as the system moved into Tennessee. At the time the Aqua spacecraft first passed over Isidore, it was classified as a Category 3 (possibly 4) hurricane, with minimum pressure of 934 mbar, maximum sustained wind speeds of 110 knots (gusting to 135) and an eye diameter of 20 nautical miles. Isidore was later downgraded to a Tropical Storm and then a Tropical Depression as it lost energy. Figures 1 and 2, two images from the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellites show no significant weather systems over the southeastern United States on September 12 and September 28 (16 days apart). However, the microwave component of the Atmospheric Infrared Sounder Experiment on NASA's Aqua spacecraft shows a striking difference. The difference in the two microwave images (figures 3 and 4) from the AIRS Advanced Microwave Sounding Unit is primarily due to flooding after Tropical Storm Isidore. Water has a very low surface emissivity at this frequency, and that causes surface water to appear very cold (even though it is not). Land appears relatively warm (well above freezing - 273 K, even at night as seen is these images), but if there is standing water, the apparent temperature drops precipitously. Figure 4, taken just about a day after the remnants of Isidore passed over the southeast, shows heavy flooding along the Mississippi, especially in the states of Mississippi and Tennessee, but other states are also affected. The spatial resolution of the AMSU-A instrument is relatively large (each measurement spot is about 25 miles in diameter at the center of the swath), but the enormous thermal contrast in the microwave between land and water makes even small flooded areas stand out., Figure 5: Difference image, 9/12 and 9/28) The Aqua spacecraft has an exact 16-day repeat cycle, that is why the pre-Isidore image is 16 days prior to the post-Isidore image. They have exactly the same coverage, which makes it possible to obtain a difference image (figure 5). The difference image is the difference between the September 28 and September 12 images shown. In the difference image, white indicates no difference at all, green is very little difference, blue/purple indicates primarily heavy flooding. Red indicates warming likely due to warmer weather. (The straight lines on the right and left edges of the difference image are caused by slight differences between the two repeat passes of Aqua). The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.
Flooding Resulting From Hurr …
PIA00365
Sol (our sun)
Atmospheric Infrared Sounder …
Title Flooding Resulting From Hurricane Isidore, Comparing Data from September 12 and 28, 2002
Original Caption Released with Image Extent of Flooding due to Hurricane Isidore revealed in images from the Atmospheric Infrared Sounding System (AIRS) on Aqua Tropical Storm Isidore was born in mid-September north of Venezuela. It subsequently hit Mexico's Yucatan Peninsula as a Category 3 hurricane and came ashore near New Orleans on September 26th packing winds just below hurricane strength. Around the time of September 27, the storm was downgraded to a tropical depression as the system moved into Tennessee. At the time the Aqua spacecraft first passed over Isidore, it was classified as a Category 3 (possibly 4) hurricane, with minimum pressure of 934 mbar, maximum sustained wind speeds of 110 knots (gusting to 135) and an eye diameter of 20 nautical miles. Isidore was later downgraded to a Tropical Storm and then a Tropical Depression as it lost energy. Figures 1 and 2, two images from the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellites show no significant weather systems over the southeastern United States on September 12 and September 28 (16 days apart). However, the microwave component of the Atmospheric Infrared Sounder Experiment on NASA's Aqua spacecraft shows a striking difference. The difference in the two microwave images (figures 3 and 4) from the AIRS Advanced Microwave Sounding Unit is primarily due to flooding after Tropical Storm Isidore. Water has a very low surface emissivity at this frequency, and that causes surface water to appear very cold (even though it is not). Land appears relatively warm (well above freezing - 273 K, even at night as seen is these images), but if there is standing water, the apparent temperature drops precipitously. Figure 4, taken just about a day after the remnants of Isidore passed over the southeast, shows heavy flooding along the Mississippi, especially in the states of Mississippi and Tennessee, but other states are also affected. The spatial resolution of the AMSU-A instrument is relatively large (each measurement spot is about 25 miles in diameter at the center of the swath), but the enormous thermal contrast in the microwave between land and water makes even small flooded areas stand out., Figure 5: Difference image, 9/12 and 9/28) The Aqua spacecraft has an exact 16-day repeat cycle, that is why the pre-Isidore image is 16 days prior to the post-Isidore image. They have exactly the same coverage, which makes it possible to obtain a difference image (figure 5). The difference image is the difference between the September 28 and September 12 images shown. In the difference image, white indicates no difference at all, green is very little difference, blue/purple indicates primarily heavy flooding. Red indicates warming likely due to warmer weather. (The straight lines on the right and left edges of the difference image are caused by slight differences between the two repeat passes of Aqua). The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.
Flooding Resulting From Hurr …
PIA00365
Sol (our sun)
Atmospheric Infrared Sounder …
Title Flooding Resulting From Hurricane Isidore, Comparing Data from September 12 and 28, 2002
Original Caption Released with Image Extent of Flooding due to Hurricane Isidore revealed in images from the Atmospheric Infrared Sounding System (AIRS) on Aqua Tropical Storm Isidore was born in mid-September north of Venezuela. It subsequently hit Mexico's Yucatan Peninsula as a Category 3 hurricane and came ashore near New Orleans on September 26th packing winds just below hurricane strength. Around the time of September 27, the storm was downgraded to a tropical depression as the system moved into Tennessee. At the time the Aqua spacecraft first passed over Isidore, it was classified as a Category 3 (possibly 4) hurricane, with minimum pressure of 934 mbar, maximum sustained wind speeds of 110 knots (gusting to 135) and an eye diameter of 20 nautical miles. Isidore was later downgraded to a Tropical Storm and then a Tropical Depression as it lost energy. Figures 1 and 2, two images from the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellites show no significant weather systems over the southeastern United States on September 12 and September 28 (16 days apart). However, the microwave component of the Atmospheric Infrared Sounder Experiment on NASA's Aqua spacecraft shows a striking difference. The difference in the two microwave images (figures 3 and 4) from the AIRS Advanced Microwave Sounding Unit is primarily due to flooding after Tropical Storm Isidore. Water has a very low surface emissivity at this frequency, and that causes surface water to appear very cold (even though it is not). Land appears relatively warm (well above freezing - 273 K, even at night as seen is these images), but if there is standing water, the apparent temperature drops precipitously. Figure 4, taken just about a day after the remnants of Isidore passed over the southeast, shows heavy flooding along the Mississippi, especially in the states of Mississippi and Tennessee, but other states are also affected. The spatial resolution of the AMSU-A instrument is relatively large (each measurement spot is about 25 miles in diameter at the center of the swath), but the enormous thermal contrast in the microwave between land and water makes even small flooded areas stand out., Figure 5: Difference image, 9/12 and 9/28) The Aqua spacecraft has an exact 16-day repeat cycle, that is why the pre-Isidore image is 16 days prior to the post-Isidore image. They have exactly the same coverage, which makes it possible to obtain a difference image (figure 5). The difference image is the difference between the September 28 and September 12 images shown. In the difference image, white indicates no difference at all, green is very little difference, blue/purple indicates primarily heavy flooding. Red indicates warming likely due to warmer weather. (The straight lines on the right and left edges of the difference image are caused by slight differences between the two repeat passes of Aqua). The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.
Flooding Resulting From Hurr …
PIA00365
Sol (our sun)
Atmospheric Infrared Sounder …
Title Flooding Resulting From Hurricane Isidore, Comparing Data from September 12 and 28, 2002
Original Caption Released with Image Extent of Flooding due to Hurricane Isidore revealed in images from the Atmospheric Infrared Sounding System (AIRS) on Aqua Tropical Storm Isidore was born in mid-September north of Venezuela. It subsequently hit Mexico's Yucatan Peninsula as a Category 3 hurricane and came ashore near New Orleans on September 26th packing winds just below hurricane strength. Around the time of September 27, the storm was downgraded to a tropical depression as the system moved into Tennessee. At the time the Aqua spacecraft first passed over Isidore, it was classified as a Category 3 (possibly 4) hurricane, with minimum pressure of 934 mbar, maximum sustained wind speeds of 110 knots (gusting to 135) and an eye diameter of 20 nautical miles. Isidore was later downgraded to a Tropical Storm and then a Tropical Depression as it lost energy. Figures 1 and 2, two images from the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellites show no significant weather systems over the southeastern United States on September 12 and September 28 (16 days apart). However, the microwave component of the Atmospheric Infrared Sounder Experiment on NASA's Aqua spacecraft shows a striking difference. The difference in the two microwave images (figures 3 and 4) from the AIRS Advanced Microwave Sounding Unit is primarily due to flooding after Tropical Storm Isidore. Water has a very low surface emissivity at this frequency, and that causes surface water to appear very cold (even though it is not). Land appears relatively warm (well above freezing - 273 K, even at night as seen is these images), but if there is standing water, the apparent temperature drops precipitously. Figure 4, taken just about a day after the remnants of Isidore passed over the southeast, shows heavy flooding along the Mississippi, especially in the states of Mississippi and Tennessee, but other states are also affected. The spatial resolution of the AMSU-A instrument is relatively large (each measurement spot is about 25 miles in diameter at the center of the swath), but the enormous thermal contrast in the microwave between land and water makes even small flooded areas stand out., Figure 5: Difference image, 9/12 and 9/28) The Aqua spacecraft has an exact 16-day repeat cycle, that is why the pre-Isidore image is 16 days prior to the post-Isidore image. They have exactly the same coverage, which makes it possible to obtain a difference image (figure 5). The difference image is the difference between the September 28 and September 12 images shown. In the difference image, white indicates no difference at all, green is very little difference, blue/purple indicates primarily heavy flooding. Red indicates warming likely due to warmer weather. (The straight lines on the right and left edges of the difference image are caused by slight differences between the two repeat passes of Aqua). The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.
Flooding Resulting From Hurr …
PIA00365
Sol (our sun)
Atmospheric Infrared Sounder …
Title Flooding Resulting From Hurricane Isidore, Comparing Data from September 12 and 28, 2002
Original Caption Released with Image Extent of Flooding due to Hurricane Isidore revealed in images from the Atmospheric Infrared Sounding System (AIRS) on Aqua Tropical Storm Isidore was born in mid-September north of Venezuela. It subsequently hit Mexico's Yucatan Peninsula as a Category 3 hurricane and came ashore near New Orleans on September 26th packing winds just below hurricane strength. Around the time of September 27, the storm was downgraded to a tropical depression as the system moved into Tennessee. At the time the Aqua spacecraft first passed over Isidore, it was classified as a Category 3 (possibly 4) hurricane, with minimum pressure of 934 mbar, maximum sustained wind speeds of 110 knots (gusting to 135) and an eye diameter of 20 nautical miles. Isidore was later downgraded to a Tropical Storm and then a Tropical Depression as it lost energy. Figures 1 and 2, two images from the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellites show no significant weather systems over the southeastern United States on September 12 and September 28 (16 days apart). However, the microwave component of the Atmospheric Infrared Sounder Experiment on NASA's Aqua spacecraft shows a striking difference. The difference in the two microwave images (figures 3 and 4) from the AIRS Advanced Microwave Sounding Unit is primarily due to flooding after Tropical Storm Isidore. Water has a very low surface emissivity at this frequency, and that causes surface water to appear very cold (even though it is not). Land appears relatively warm (well above freezing - 273 K, even at night as seen is these images), but if there is standing water, the apparent temperature drops precipitously. Figure 4, taken just about a day after the remnants of Isidore passed over the southeast, shows heavy flooding along the Mississippi, especially in the states of Mississippi and Tennessee, but other states are also affected. The spatial resolution of the AMSU-A instrument is relatively large (each measurement spot is about 25 miles in diameter at the center of the swath), but the enormous thermal contrast in the microwave between land and water makes even small flooded areas stand out., Figure 5: Difference image, 9/12 and 9/28) The Aqua spacecraft has an exact 16-day repeat cycle, that is why the pre-Isidore image is 16 days prior to the post-Isidore image. They have exactly the same coverage, which makes it possible to obtain a difference image (figure 5). The difference image is the difference between the September 28 and September 12 images shown. In the difference image, white indicates no difference at all, green is very little difference, blue/purple indicates primarily heavy flooding. Red indicates warming likely due to warmer weather. (The straight lines on the right and left edges of the difference image are caused by slight differences between the two repeat passes of Aqua). The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.
Flooding Resulting From Hurr …
PIA00365
Sol (our sun)
Atmospheric Infrared Sounder …
Title Flooding Resulting From Hurricane Isidore, Comparing Data from September 12 and 28, 2002
Original Caption Released with Image Extent of Flooding due to Hurricane Isidore revealed in images from the Atmospheric Infrared Sounding System (AIRS) on Aqua Tropical Storm Isidore was born in mid-September north of Venezuela. It subsequently hit Mexico's Yucatan Peninsula as a Category 3 hurricane and came ashore near New Orleans on September 26th packing winds just below hurricane strength. Around the time of September 27, the storm was downgraded to a tropical depression as the system moved into Tennessee. At the time the Aqua spacecraft first passed over Isidore, it was classified as a Category 3 (possibly 4) hurricane, with minimum pressure of 934 mbar, maximum sustained wind speeds of 110 knots (gusting to 135) and an eye diameter of 20 nautical miles. Isidore was later downgraded to a Tropical Storm and then a Tropical Depression as it lost energy. Figures 1 and 2, two images from the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellites show no significant weather systems over the southeastern United States on September 12 and September 28 (16 days apart). However, the microwave component of the Atmospheric Infrared Sounder Experiment on NASA's Aqua spacecraft shows a striking difference. The difference in the two microwave images (figures 3 and 4) from the AIRS Advanced Microwave Sounding Unit is primarily due to flooding after Tropical Storm Isidore. Water has a very low surface emissivity at this frequency, and that causes surface water to appear very cold (even though it is not). Land appears relatively warm (well above freezing - 273 K, even at night as seen is these images), but if there is standing water, the apparent temperature drops precipitously. Figure 4, taken just about a day after the remnants of Isidore passed over the southeast, shows heavy flooding along the Mississippi, especially in the states of Mississippi and Tennessee, but other states are also affected. The spatial resolution of the AMSU-A instrument is relatively large (each measurement spot is about 25 miles in diameter at the center of the swath), but the enormous thermal contrast in the microwave between land and water makes even small flooded areas stand out., Figure 5: Difference image, 9/12 and 9/28) The Aqua spacecraft has an exact 16-day repeat cycle, that is why the pre-Isidore image is 16 days prior to the post-Isidore image. They have exactly the same coverage, which makes it possible to obtain a difference image (figure 5). The difference image is the difference between the September 28 and September 12 images shown. In the difference image, white indicates no difference at all, green is very little difference, blue/purple indicates primarily heavy flooding. Red indicates warming likely due to warmer weather. (The straight lines on the right and left edges of the difference image are caused by slight differences between the two repeat passes of Aqua). The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.
1-13 of 13