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3-D Mars' North Pole
Title 3-D Mars' North Pole
Explanation This dramatic premier [ http://ltpwww.gsfc.nasa.gov/tharsis/agu_f98.html ] three-dimensional visualization of Mars' north pole is based on elevation measurements made by an orbiting laser. During the Spring and Summer [ http://ltpwww.gsfc.nasa.gov/tharsis/npole.html ] of 1998 the Mars Orbiter Laser Altimeter [ http://ltpwww.gsfc.nasa.gov/tharsis/mola.html#Introduction ] (MOLA) flashed laser pulses toward the Martian surface from the Global Surveyor spacecraft and recorded the time it took to detect the reflection [ http://ltpwww.gsfc.nasa.gov/tharsis/mola.html#Principles ]. This timing data has now been translated to a detailed topographic map of Mars' north polar terrain [ http://antwrp.gsfc.nasa.gov/apod/ap980924.html ]. The map indicates that the ice cap is is about 1,200 kilometers across, a maximum of 3 kilometers thick, and cut by canyons and troughs up to 1 kilometer deep. The measurements also [ http://earth.agu.org/pubs/toc/gl/gl_25_24.html ] indicate that the cap is composed primarily of water ice with a total volume of only about four percent of planet Earth's Antarctic ice sheet [ http://antwrp.gsfc.nasa.gov/apod/ap951222.html ]. In all it represents at most a tenth of the amount of water some scientists believe once existed on ancient Mars [ http://www.sciam.com/1196issue/1196kargel.html ]. Where did all the water [ http://humbabe.arc.nasa.gov/mgcm/faq/wetmars.html ] go?
Topographical Mars
Title Topographical Mars
Explanation Contrasting colors trace changing elevations in this new high-resolution topographic map of Mars [ http://pao.gsfc.nasa.gov/gsfc/spacesci/pictures/mola/mars3d.htm ]. Just released [ ftp://pao.gsfc.nasa.gov/pub/PAO/Releases/1999/99-71.txt ], the data were gathered in 1998 and 1999 by the Mars Orbiter Laser Altimeter [ http://ltpwww.gsfc.nasa.gov/tharsis/mola.html#Introduction ] (MOLA) onboard the Mars Global Surveyor spacecraft. The martian topography is seen to range over 19 miles between the highest volcanic peaks (white) and the lowest regions (purple). Along with the striking difference [ http://www.msss.com/http/ps/di.html ] between the Red Planet's [ http://www.uapress.arizona.edu/online.bks/mars/contents.htm ] low northern hemisphere (top) and high southern regions, one of the most noticeable features on the map [ http://www-pdsimage.wr.usgs.gov/PDS/public/mapmaker/mapmkr.htm ] is the large blue-purple southern depression corresponding to the Hellas basin. Likely the result of an asteroid impact, Mars' deepest basin is about 1300 miles across making it one of the largest impact features [ http://antwrp.gsfc.nasa.gov/apod/ap960906.html ] in the Solar System. Explorations [ http://antwrp.gsfc.nasa.gov/apod/ap981216.html ] of MOLA's rich topographic database are expected to produce insights into water flows and the geologic history [ http://helio.estec.esa.nl/intermarsnet/redreport/node20.html ] of Mars.
TOPEX/El Niño Watch - El Niñ …
PIA01164
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - El Niño Warm Water Pool Decreasing, Jan, 08, 1998
Original Caption Released with Image This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Jan. 8, 1998, and sea surface height is an indicator of the heat content of the ocean. The volume of the warm water pool related to the El Niño has decreased by about 40 percent since its maximum in early November, but the area of the warm water pool is still about one and a half times the size of the continental United States. The volume measurements are computed as the sum of all the sea surface height changes as compared to normal ocean conditions. In addition, the maximum water temperature in the eastern tropical Pacific, as measured by the National Oceanic and Atmospheric Administration (NOAA), is still higher than normal. Until these high temperatures diminish, the El Niño warm water pool still has great potential to disrupt global weather because the high water temperatures directly influence the atmosphere. Oceanographers believe the recent decrease in the size of the warm water pool is a normal part of El Niño's natural rhythm. TOPEX/Poseidon has been tracking these fluctuations of the El Niño warm pool since it began in early 1997. These sea surface height measurements have provided scientists with their first detailed view of how El Niño's warm pool behaves because the TOPEX/Poseidon satellite measures the changing sea surface height with unprecedented precision. In this image, the white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using these global data, limited regional measurements from buoys and ships, and a forecasting model of the ocean-atmosphere system, the National Centers for Environmental Prediction (NCEP) of the National Oceanic and Atmospheric Administration, (NOAA), has issued an advisory indicating the presence of a strong El Niño condition throughout the winter. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
TOPEX/El Niño Watch - Topex/ …
PIA01498
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - Topex/Poseidon Shows Unusual Pacific, November 29, 1998
Original Caption Released with Image This image of the Pacific Ocean was produced using sea-surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on November 29, 1998, these sea surface heights are an indicator of the changing amount of heat stored in the ocean. The image shows that an unusual large-scale warming (shown here in red and white) of the western Pacific first observed in early November has spread to the central Pacific. The low sea level or cold pool of water commonly referred to as La Niña, shown in purple, has remained essentially the same, changing very little in size and heat content. Oceanographers believe that the coexistence of these two contrasting conditions -- cooler water along the equator and warmer water in both the northern and southern hemispheres -- indicates that the ocean and the climate system have not recovered from the record-breaking warming that has occurred during the past two years. The purple areas are 14 to 18 centimeters (6 to 7 inches) below normal and the blue areas are 5 to 13 centimeters (2 to 5 inches) below normal. The white areas show the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it is about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
TOPEX/El Niño Watch - La Niñ …
PIA01497
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - La Niña looks "frozen" in Pacific, November 8, 1998
Original Caption Released with Image This image of the Pacific Ocean was produced using sea-surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on November 8, 1998, these sea surface heights are an indicator of the changing amount of heat stored in the ocean. The image shows that the low sea level or cold pool of water commonly referred to as La Niña, shown in purple, has stayed about the same for the last five months changing very little in size and heat content. The satellite's ability to monitor the entire ocean indicates there is also a large-scale warming taking place in the western Pacific, shown here in red and white. Oceanographers believe that the coexistence of these two contrasting conditions -- cooler water along the equator and warmer water in both the northern and southern hemispheres -- indicates that the ocean and the climate system have not recovered from the record-breaking warming that has occurred during the past two years. The purple areas are 14 to 18 centimeters (6 to 7 inches) below normal and the blue areas are 5 to 13 centimeters (2 to 5 inches) below normal. The white areas show the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it is about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
TOPEX/El Niño Watch - Moistu …
PIA01450
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - Moisture in the Atmosphere, Jan & Feb, 1998
Original Caption Released with Image his series of six images shows the evolution of atmospheric water vapor over the Pacific Ocean during the 1998 El Niño condition. Higher than normal ocean water temperatures increase the rate of evaporation, and the resulting warm moist air rises into the atmosphere, altering global weather patterns. Data obtained by the Microwave Limb Sounder (MLS) on NASA's Upper Atmosphere Research Satellite (UARS) during January and February 1998 show a decrease in the extent of high levels of water vapor (red) over the eastern equatorial Pacific and an increase in water vapor (yellow to red) over the northwestern Pacific off the coast of Japan. This area is a breeding ground for winter storms that move eastward toward North America. During this El Niño condition, the southern tropical jet stream has shifted northward, bringing additional moisture from the tropics. When these two sources of moisture converge near California, they produce storms with higher-than-normal rainfall. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
TOPEX/El Niño Watch - Satell …
PIA01461
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - Satellite shows Pacific Stabilizing, July 11, 1998
Original Caption Released with Image height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on July 11, 1998, sea surface height is an indicator of the heat content of the ocean. The purple area in the center of the image is a pulse of cold water moving across the equator which the satellite measures as a region of lower than normal sea level. This image shows that the rapid cooling of the central tropical Pacific has stabilized and this area of low sea level has stayed in about the same place since mid-June. The purple areas are about 18 centimeters (7 inches) below normal, creating a deficit in the heat supply to the surface waters. It is not certain yet, if this current cooling trend (shown in purple) will eventually evolve into a long-lasting La Niña situation. Remnants of the El Niño warm water pool, shown here in red and white, are still lingering to the north and south of the equator in the center of this image. The effects of El Niño can remain in the climate system for a long time and could still impact weather conditions around the world. The satellite's sea-surface height measurements have provided scientists with a detailed view of the 1997-98 El Niño because the TOPEX/Poseidon satellite measures the changing sea-surface height with unprecedented precision. In this image, the white areas show the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. The purple areas are 14 to 18 centimeters (6 to 7 inches) below normal and the blue areas are 5 to 13 centimeters (2 to 5 inches) below normal. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. A La Niña situation is essentially the opposite of an El Niño condition, where the trade winds are stronger than normal and the cold water that normally exists along the coast of South America extends to the central equatorial Pacific. A La Niña situation also changes global weather patterns, and is associated with less moisture in the air resulting in less rain along the coasts of North and South America. TOPEX/Poseidon will be able to track a potentially developing La Niña with the same accuracy.
TOPEX/El Niño Watch - El Niñ …
PIA01451
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - El Niño is Still Lingering in the Pacific May 3, 1998
Original Caption Released with Image This image of the Pacific Ocean was produced using sea-surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea-surface height relative to normal ocean conditions on May 3, 1998, and sea-surface height is an indicator of the heat content of the ocean. The image shows that sea-surface height along the central and eastern equatorial Pacific has maintained a near normal state since March 1998. However, the western equatorial Pacific, shown here in purple, has not returned to a normal state and is still about 30 centimeters (12 inches) below normal sea level. Remnants of the El Niño warm water pool, shown in red and white, are situated to the north of the equator. Oceanographers indicate these measurements show that the Pacific has not yet fully recovered from this large El Niño event. These sea-surface height measurements have provided scientists with a detailed view of how the 1997-98 El Niño's warm water pool behaves because the TOPEX/Poseidon satellite measures the changing sea-surface height with unprecedented precision. In this image, the white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using satellite imagery, buoy and ship data, and a forecasting model of the ocean-atmosphere system, the National Oceanic and Atmospheric Administration, (NOAA), has continued to issue an advisory indicating the so-called El Niño weather conditions that have impacted much of the United States and the world are expected to remain through the spring. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
TOPEX/El Niño Watch - Satell …
PIA01474
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - Satellite Shows Pacific Running Hot and Cold, September 12, 1998
Original Caption Released with Image This image of the Pacific Ocean was produced using sea-surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on September 12, 1998, these sea surface heights are an indicator of the changing amount of heat stored in the ocean. The tropical Pacific Ocean continues to exhibit the complicated characteristics of both a lingering El Niño, and a possibly waning La Niña situation. This image shows that the rapid cooling of the central tropical Pacific has slowed and this area of low sea level (shown in purple) has decreased slightly since last month. It is still uncertain, scientists say, that this cold pool will evolve into a long-lasting La Niña situation. Remnants of the El Niño warm water pool, shown here in red and white, are still lingering to the north and south of the equator. The coexistence of these two contrasting conditions indicates that the ocean and the climate system remain in transition. These strong patterns have remained in the climate system for many months and will continue to influence weather conditions around the world in the coming fall and winter. The satellite's sea-surface height measurements have provided scientists with a detailed view of the 1997-98 El Niño because the TOPEX/Poseidon satellite measures the changing sea-surface height with unprecedented precision. The purple areas are about 18 centimeters (7 inches) below normal, creating a deficit in the heat supply to the surface waters. The white areas show the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. The purple areas are 14 to 18 centimeters (6 to 7 inches) below normal and the blue areas are 5 to 13 centimeters (2 to 5 inches) below normal. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. A La Niña situation is essentially the opposite of an El Niño condition, but during La Niña the trade winds are stronger than normal and the cold water that normally exists along the coast of South America extends to the central equatorial Pacific. A La Niña situation also changes global weather patterns, and is associated with less moisture in the air resulting in less rain along the west coasts of North and South America. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
TOPEX/El Niño Watch - El Niñ …
PIA01453
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - El Niño in Retreat, Pacific in Transition, June 14, 1998
Original Caption Released with Image This image of the Pacific Ocean was produced using sea-surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea-surface height relative to normal ocean conditions on June 14, 1998, and sea-surface height is an indicator of the heat content of the ocean. This image shows that the tropical Pacific has been switching from warm to cold during the last few months. The purple area in the center of the image is a pulse of cold water moving across the equator which the satellite measures as a region of lower than normal sea level. Scientists indicate that it appears that the central equatorial Pacific ocean will stay colder than normal for some time to come because sea level is about 18 centimeters (7 inches) below normal, creating a deficit in the heat supply to the surface waters. It is not certain yet, if this current cooling trend (shown in purple) will eventually evolve into a long-lasting La Niña situation. Remnants of the El Niño warm water pool, shown here in red and white, are still lingering north of the equator in the center of this image. The effects of El Niño can remain in the climate system for a long time and could still impact weather conditions around the world. The satellite's sea-surface height measurements have provided scientists with a detailed view of the 1997-98 El Niño because the TOPEX/Poseidon satellite measures the changing sea-surface height with unprecedented precision. In this image, the white areas show the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. The purple areas are 14 to 18 centimeters (6 to 7 inches) below normal and the blue areas are 5 to 13 centimeters (2 to 5 inches) below normal. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. A La Niña situation is essentially the opposite of an El Niño condition, where the trade winds are stronger than normal and the cold water that normally exists along the coast of South America extends to the central equatorial Pacific. A La Niña situation also changes global weather patterns, and is associated with less moisture in the air resulting in less rain along the coasts of North and South America. TOPEX/Poseidon will be able to track a potentially developing La Niña with the same accuracy. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
TOPEX/El Niño Watch - Little …
PIA01473
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - Little Change in Pacific, August 13, 1998
Original Caption Released with Image This image of the Pacific Ocean was produced using sea-surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on August 13, 1998, sea surface height is an indicator of the heat content of the ocean. The purple area in the center of the image is a pool of cold water that the satellite measures as a region of lower than normal sea level. This image shows that the rapid cooling of the central tropical Pacific has stalled and this area of low sea level has stayed in about the same place for the last two months. The purple areas are about 18 centimeters (7 inches) below normal, creating a deficit in the heat supply to the surface waters. It is not certain yet, if this current cooling trend (shown in purple) will eventually evolve into a long-lasting La Niña situation. Remnants of the El Niño warm water pool, shown here in red and white, are still lingering to the north and south of the equator. The effects of El Niño can remain in the climate system for a long time and could still impact weather conditions around the world. The satellite's sea-surface height measurements have provided scientists with a detailed view of the 1997-98 El Niño because the TOPEX/Poseidon satellite measures the changing sea-surface height with unprecedented precision. In this image, the white areas show the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. The purple areas are 14 to 18 centimeters (6 to 7 inches) below normal and the blue areas are 5 to 13 centimeters (2 to 5 inches) below normal. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. A La Niña situation is essentially the opposite of an El Niño condition, where the trade winds are stronger than normal and the cold water that normally exists along the coast of South America extends to the central equatorial Pacific. A La Niña situation also changes global weather patterns, and is associated with less moisture in the air resulting in less rain along the coasts of North and South America. TOPEX/ Poseidon will be able to track a potentially developing La Niña with the same accuracy. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
TOPEX/El Niño Watch - Warm W …
PIA01448
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - Warm Water Pool is Thinning, Feb, 5, 1998
Original Caption Released with Image This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Feb. 5, 1998 and sea surface height is an indicator of the heat content of the ocean. The area and volume of the El Niño warm water pool that is affecting global weather patterns remains extremely large, but the pool has thinned along the equator and near the coast of South America. This "thinning" means that the warm water is not as deep as it was a few months ago. Oceanographers indicate this is a classic pattern, typical of a mature El Niño condition that they would expect to see during the ocean's gradual transition back to normal sea level. In this image, the white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using satellite imagery, buoy and ship data, and a forecasting model of the ocean-atmosphere system, the National Oceanic and Atmospheric Administration, (NOAA), has continued to issue an advisory indicating the so-called El Niño weather conditions that have impacted much of the United States and the world are expected to remain through the spring. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
TOPEX/El Niño Watch - Satell …
PIA01449
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - Satellite shows El Niño-related Sea Surface Height, Mar, 14, 1998
Original Caption Released with Image This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Mar. 14, 1998 and sea surface height is an indicator of the heat content of the ocean. The image shows that the sea surface height along the central equatorial Pacific has returned to a near normal state. Oceanographers indicate this is a classic pattern, typical of a mature El Niño condition. Remnants of the El Niño warm water pool, shown in red and white, are situated to the north and south of the equator. These sea surface height measurements have provided scientists with a detailed view of how the 1997-98 El Niño's warm pool behaves because the TOPEX/Poseidon satellite measures the changing sea surface height with unprecedented precision. In this image, the white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using satellite imagery, buoy and ship data, and a forecasting model of the ocean-atmosphere system, the National Oceanic and Atmospheric Administration, (NOAA), has continued to issue an advisory indicating the so-called El Niño weather conditions that have impacted much of the United States and the world are expected to remain through the spring.
Elevation Measurement Profil …
PIA01338
Sol (our sun)
MOLA
Title Elevation Measurement Profile of Mars
Original Caption Released with Image The elevation measurements were collected by the Mars Orbiter Laser Altimeter (MOLA) aboard Global Surveyor during the spring and summer of 1998, as the spacecraft orbited Mars in an interim elliptical orbit. MOLA sends laser pulses toward the planet and measures the precise amount of time before the reflected signals are received back at the instrument. From this data, scientists can infer surface and cloud heights. During its mapping of the north polar cap, the MOLA instrument also made the first direct measurement of cloud heights on the red planet. Reflections from the atmosphere were obtained at altitudes from just above the surface to more than nine miles (approximately 15 kilometers) on about 80 percent of the laser profiles. Most clouds were observed at high latitudes, at the boundary of the ice cap and surrounding terrain. Clouds observed over the polar cap are likely composed of carbon dioxide that condenses out of the atmosphere during northern hemisphere winter. Many clouds exhibit dynamic structure probably caused by winds interacting with surface topography, much as occurs on Earth when winds collide with mountains to produce turbulence. The principal investigator for MOLA is Dr. David E. Smith of Goddard. The MOLA instrument was designed and built by the Laser Remote Sensing Branch of Laboratory for Terrestrial Physics at Goddard. The Mars Global Surveyor Mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for the NASA Office of Space Science.
MGS Mars Orbiter Laser Altim …
PIA00959
Sol (our sun)
MOLA
Title MGS Mars Orbiter Laser Altimeter Topographic Profile of Impact Crater
Original Caption Released with Image Among the myriad of interesting landforms sampled by MOLA on its first traverse across the Red Planet on 15 September 1997 is this 13-mile (21-kilometer) diameter impact crater located at ~ 48°N. The figure shows the topography, the computed position of the spacecraft groundtrack (solid line) and the track adjusted to correct for image location error (dashed line). The topographic profile provides some of the first indications of how landscape modification has operated in Martian geologic history. The relief of the crater rim, in combination with the steepness (over 20°) of the inner crater wall, are intriguing in that most craters of this size are much more subdued. The shape of the outer ejecta blanket of the crater likely indicates impact into an H2O rich crust. Issues concerning how craters such as this can be used to understand the properties of the uppermost crust of Mars in regions where the role of water and other volatiles may be important can be addressed with the high spatial and vertical resolution topographic profiles that will be acquired by MOLA once it starts its detailed mapping of the Red Planet in March of 1998.
TOPEX/El Niño Watch - La Niñ …
PIA01525
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - La Niña Weakening, January 17, 1999
Original Caption Released with Image This image of the Pacific Ocean was produced using sea-surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on January 17, 1999, sea surface height is an indicator of the heat content of the ocean. This image shows that the unusual large-scale warming (shown here in red and white) in the northwest Pacific that was first observed by the satellite in November 1998 has increased in size and spread east to the central Pacific and south to the equator. The low sea level or cold pool of water along the equator, commonly referred to as La Niña (shown in purple), has weakened in size and heat content during the last several months. Although weakening, the La Niña pattern continues to exert a strong influence on the worldwide climate system. According to oceanographers, the cold La Niña water acts like a boulder in a stream, steering the planet's prevailing winds and changing the course of storms that are born over the ocean. Equally important to North America's winter weather is the very large area of unusually warm Western Pacific ocean. Although the appearance of this feature is not fully understood or anticipated, it is adding energy to the winter storms coming out of the North Pacific which is fueling the very volatile weather over the continental U.S. In this image, the white areas show the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. The purple areas are 14 to 18 centimeters (6 to 7 inches) below normal and the blue areas are 5 to 13 centimeters (2 to 5 inches) below normal. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
TOPEX/El Niño Watch - La Niñ …
PIA01526
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - La Niña Hangs On, February 27, 1999
Original Caption Released with Image Propulsion Laboratory for NASA's Office of Earth Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA., The cold pool of water in the Pacific known as "La Niña" still persists, although it is slowly weakening, according to scientists studying new data from the U.S.-French TOPEX/Poseidon satellite. A new image, produced using sea-surface height measurements taken by the satellite, is available on the Internet at http://www.jpl.nasa.gov/elnino/. It shows sea-surface height on February 27, 1999 relative to normal ocean conditions, reflecting the heat content of the ocean. The low sea level or cold pool of water along the equator (shown in purple and blue), commonly referred to as La Niña, still dominates the equatorial Pacific Ocean. This La Niña, which first appeared in May through June 1998, still persists, although it is slowly weakening, scientists say. Given its persistence and present strength, the ocean cooling trend is expected to continue to exert a strong influence on global climate systems throughout the spring and into the early summer. This situation is similar to the 1997-1998 El Niño, which extended into early summer 1998. The world's oceans are the great reservoirs of heat that influence global climate because they can cool or heat the atmosphere above. This transfer of heat drives weather patterns across both land and sea. La Niña provides a physical link connecting the large, slow changes in the ocean with predictable changes in day-to-day weather."La Niña shifts the high-altitude weather highway known as the jet stream," said Dr. William Patzert, an oceanographer at NASA's Jet Propulsion Laboratory. "It funnels storm tracks to the Pacific Northwest, which has resulted in heavy rainfall and lots of snow in that region so far, as well as the upper Midwest. Much of the Southwest, by contrast, has been shielded from stormy weather and, as a result, has received significantly less precipitation than normal to date. This year's La Niña was average in its intensity, but at its peak, it was associated with a 15 to 20-centimeter deep trough (6 to 8 inches) in the central tropical Pacific," Patzert said. "The depression was correlated with a 2 to 3-degree Centigrade (about 3.5 to 5.5 degrees Fahrenheit) dip in normal ocean surface temperatures." The image also shows that the very large, unusual area of higher or warmer water (shown here in red and white) in the western Pacific Ocean, from the tropics to the Gulf of Alaska, continues to expand. Although the appearance of this feature is not fully understood, it is recognized as influential to overall weather and climate. The white areas in the image indicate that the sea-surface height is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, sea-surface height is about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions. The purple areas are between 14 to 18 centimeters (6 to 7 inches) below normal, and the blue areas are between 5 to 13 centimeters (2 to 5 inches) below normal. The TOPEX/Poseidon mission is managed by the Jet
3000 Mile Laser Altimeter Pr …
PIA00958
Sol (our sun)
MOLA
Title 3000 Mile Laser Altimeter Profile Across Northern Hemisphere of Mars
Original Caption Released with Image Topographic profile across the northern hemisphere of Mars from the Mars Orbiter Laser Altimeter (MOLA). The profile was obtained during the Mars Global Surveyor Capture Orbit Calibration Pass on September 15, 1997 and represents 20 minutes of data collection. The profile has a length of approximately 3000 miles (5000 kilometers). The large bulge is the western part of the Elysium rise, the second largest volcanic province on Mars, and shows over 3 miles (5 kilometers) of vertical relief. This area contains deep chasms that reflect tectonic, volcanic and erosional processes. In contrast is the almost 1featureless1 northern plains region of Mars, which shows only hundreds of meters of relief at scales the size of the United States. Plotted for comparison is the elevation of the Viking Lander 2 site, which is located 275 miles (445 kilometers) west of the profile. At the southernmost extent of the trace is the transition from the northern plains to the ancient southern highlands. Characterizing the fine-scale nature of topography in this chaotic region is crucial to testing theories for how the dichotomy between the geologically distinctive northern lowlands and southern uplands formed and subsequently evolved. The spatial resolution of the profile is approximately 1000 feet (330 meters) and the vertical resolution is approximately 3 feet (1 meter). When the Mars Global Surveyor mapping mission commences in March, 1998, the MOLA instrument will collect 72 times as much data every day for a period of two years.
MGS MOC Coverage of Mars Pol …
PIA02310
Sol (our sun)
Mars Orbiter Camera
Title MGS MOC Coverage of Mars Polar Lander Region
Original Caption Released with Image . The selection criteria were to find a place that was relatively flat and relatively smooth, but which displayed characteristics of the south polar layered materials. The inset (upper left) shows the location of the landing zone with respect to the south polar residual (year-round) ice cap. The base map used here is a mosaic of Viking Orbiter images from the U.S. Geological Survey. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO., High-resolution views of the Mars Polar Lander [ http://www.marspolarlander.com/ ] landing zone were essential to the selection of a safe place for the December 3, 1999, landing to occur. The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) took its first pictures of the landing zone in December 1997 [ http://www.msss.com/mars_images/3_9_98_release/7200/index.html ] and January 1998 [ http://www.msss.com/mars_images/3_9_98_release/9500/index.html ]. After that time, the south polar region was not accessible to the camera until June 1999, when the south polar winter was ending and the sun began to dawn on this region once again. Since the beginning of June 1999, an intense period of imaging has been conducted over the landing zone so that a safe site could be found. The final site has now been identified, and the pictures shown here give some idea of what the Mars Polar Lander will encounter a little more than three months from now. This figure shows the zone originally proposed by the Mars Volatiles and Climate Surveyor (MVACS) [ http://mvacs.ess.ucla.edu/ ] science team for the Mars Polar Lander mission, which spanned the region from 72° to 78°S latitude and 170° to 230°W longitude. The thin white boxes and lines crossing the proposed zone outline MOC images taken between the first week in June 1999 and the first week in August 1999. The longest images were taken at 12 by 18 meters (39 by 59 feet) per pixel, there are three sets of long images, each taken during a given week in June as the terminator (the line separating "night" from "day") moved south across the landing zone. Smaller swaths represent images at higher resolution. The best resolution so far achieved is about 4 meters (13 ft) per pixel, better images will be taken in September and October as the sun rises farther and the surface becomes better illuminated. This figure shows the location of the primary (blue) and secondary (white) landing ellipses, which were selected on the basis of interpretation of the MGS data, in particular data from the Mars Orbiter Laser Altimeter [ http://ltpwww.gsfc.nasa.gov/tharsis/98lander.html ] and the Mars Orbiter Camera [ http://www.msss.com/mars_images/index.html ]
TOPEX/El Niño Watch - El Niñ …
PIA00837
Sol (our sun)
Altimeter
Title TOPEX/El Niño Watch - El Niño Warm Water Pool Returns to Near Normal State, Mar, 14, 1998
Original Caption Released with Image This image of the Pacific Ocean was produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The image shows sea surface height relative to normal ocean conditions on Mar. 14, 1998 and sea surface height is an indicator of the heat content of the ocean. The image shows that the sea surface height along the central equatorial Pacific has returned to a near normal state. Oceanographers indicate this is a classic pattern, typical of a mature El Niño condition. Remnants of the El Niño warm water pool, shown in red and white, are situated to the north and south of the equator. These sea surface height measurements have provided scientists with a detailed view of how the 1997-98 El Niño's warm pool behaves because the TOPEX/Poseidon satellite measures the changing sea surface height with unprecedented precision. In this image, the white and red areas indicate unusual patterns of heat storage, in the white areas, the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal, in the red areas, it's about 10 centimeters (4 inches) above normal. The green areas indicate normal conditions, while purple (the western Pacific) means at least 18 centimeters (7 inches) below normal sea level. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows a large mass of warm water (the red and white area) that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. The displacement of so much warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. Using satellite imagery, buoy and ship data, and a forecasting model of the ocean-atmosphere system, the National Oceanic and Atmospheric Administration, (NOAA), has continued to issue an advisory indicating the so-called El Niño weather conditions that have impacted much of the United States and the world are expected to remain through the spring. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov
Detailed View of Cliff-face …
PIA01479
Sol (our sun)
Mars Orbiter Camera
Title Detailed View of Cliff-face in the North Polar Layered Deposits
Original Caption Released with Image On Earth, geologists use layers of rock to "read" the history of our planet. Where rocks were initially formed as layers of sediment, the historic record of Earth is deciphered by knowing that older layers are found beneath the younger layers. Scientists investigating changes in Earth's climate over the past few million years also use this principle to examine cores of ice from Greenland and Antarctica. Layered rock and layered polar deposits on Mars may also preserve a comparable record of that planet's geologic and environmental history. The martian north and south polar regions are covered by large areas of layered deposits. Since their discovery in the early 1970's, these polar layered deposits have been cited as the best evidence that the martian climate experiences cyclic changes over time. It was proposed that detailed investigation of the polar layers ("e.g.,", by landers and/or human beings) would reveal a climate record of Mars in much the same way that ice cores from Antarctica are used to study past climates on Earth. On January 3, 1999, NASA's Mars Polar Lander and Deep Space 2 Penetrators will launch on a journey to study the upper layers of these deposits in the martian southern hemisphere. Meanwhile, investigation of the north polar layered deposits has advanced significantly this year with the acquisition of MGS data. The Mars Orbiter Laser Altimeter acquired new topographic profiles over the north polar deposits in June and early July, 1998, and dozens of new high resolution images were taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) from mid-July to mid-September, 1998. When it was proposed to NASA in 1985, one of the original objectives of MOC was to determine whether the polar layered deposits--then thought to consist of 10 to 100 layers each between 10 and 100 meters (33 to 330 feet) thick--have more and thinner layers in them. The layers were proposed to have formed by slow accumulation of dust and ice--perhaps only 100 micrometers (0.004 inches) per year. A layer 10 meters (33 feet) thick would take 100,000 years to accumulate, roughly equal to the timescale of climate changes predicted by computer models. The image shown here (right image) was taken at 11:52 p.m. PDT on July 30, 1998, near the start of the 461st orbit of Mars Global Surveyor. The picture shows a slope along the edge of the permanent north polar cap of Mars that has dozens of layers exposed in it. The image shows many more layers than were visible to the Viking Orbiters in the 1970s (left images). The layers appear to have different thicknesses (some thinner than 10 meters (33 feet)) and different physical expressions. Some of the layers form steeper slopes than others, suggesting that they are more resistant to erosion. The more resistant layers might indicate that a cement (possibly ice) is present, making those layers stronger. All of the layers appear to have a rough texture that might be the result of erosion and/or redistribution of sediment and polar ice on the slope surface. The presence of many more layers than were seen by Viking is an important and encouraging clue that suggests that future investigation of polar layered deposits by landers and, perhaps some day, by human explorers, will eventually lead to a better understanding of the of the polar regions and the climate history recorded there. Our view of these deposits will be much improved--starting in late March 1999--when the Mapping Phase of the MGS mission begins, and MOC will be able to obtain images with resolutions of 1.5 meters (5 feet) per pixel. [The Viking Images (left)]: Regional and local context of MOC image 46103. The small figure in the upper right corner is a map of the north polar region, centered on the pole with 0° longitude located in the lower middle of the frame. A small black box within the polar map indicates, the location of the Viking Orbiter 2 image used here for local context. The Viking image, 560b60, was taken in March 1978, toward the end of Northern Spring. The thin strip superposed on the Viking image is MOC image 46103, reduced in size to mark its placement relative to the Viking context image. The black box on the MOC image shows the location of the subframe highlighted here (right image). Illumination is from the left in the Viking image. The 10 kilometer scale bar also represents approximately 6.2 miles. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
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