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Altimeter of Jet Propulsion Laboratory (JPL) from 1997
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Inside Mars
| Title |
Inside Mars |
| Explanation |
What's inside Mars [ http://svs.gsfc.nasa.gov/imagewall/MOLA/mola_3_2000.html ]? From orbit, the Mars Global Surveyor (MGS) spacecraft [ http://mars.jpl.nasa.gov/mgs/realtime/mgsrt.html ] has recorded detailed images of the red planet since [ http://www.msss.com/mars_images/moc/mgs_moc_archive.html ] July 1997. Still, its cameras can not look beneath the surface. But minute changes in the spacecraft's orbital velocity are produced by variations in the planet's gravitational field, and these changes are related to interior density fluctuations. When the subtle orbital changes were measured using MGS radio science [ http://nova.stanford.edu/projects/mgs/ ] experiments and combined with the accurate Mars Orbiter Laser Altimeter topographical data [ http://antwrp.gsfc.nasa.gov/apod/ap990528.html ], researchers were able to produce a map of the thickness of the martian crust [ http://mars.jpl.nasa.gov/mgs/sci/mola/mar10-2000/internal_paper.html ]. In this color cut-away diagram of the results, red colors correspond to thin and blue to thick areas of the crust which rides above the martian mantle [ http://banzai.msi.umn.edu/mars/ ]. From the global map, the crust is seen [ http://pao.gsfc.nasa.gov/gsfc/spacesci/mars/mars.htm ] to range from about 20 to 50 miles thick and shows a dramatic difference between the generally thinner northern hemisphere to thicker southern hemisphere crust. For the newly formed planet, the thin crust would have promoted rapid cooling [ http://svs.gsfc.nasa.gov/imagewall/MOLA/pressrelease.txt ] and may have given rise to a large northern ocean [ http://earthsky.com/1999/es990519.html ] on early Mars [ http://antwrp.gsfc.nasa.gov/apod/ap970627.html ]. |
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TOPEX/El Niño Watch - June 2
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PIA00735
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - June 25, 1997 |
| 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 25, 1997 and provides more convincing information that the weather-disrupting phenomenon known as El Niño is back and getting stronger. 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 surface area covered by the warm water mass is about one and one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21-30 degrees Celsius (70-85 degrees Fahrenheit), is about 30 times the volume of water in all the U.S. Great Lakes combined. 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 the early indications of El Niño conditions. |
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TOPEX/El Niño Watch - Indone
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PIA00742
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - Indonesia Area, December, 1996 and August, 1997 |
| Original Caption Released with Image |
These images of the Pacific Ocean near Indonesia were produced using sea surface height measurements taken by the U.S.-French TOPEX/Poseidon satellite. The images show sea surface height relative to normal ocean conditions during December 1996 and August 1997. The difference in sea level between these months is tied to the movement of warm water away from Indonesia. In December (left image), red and white areas indicate the presence of warm, higher than average sea level around Indonesia. At this time, massive amounts of warm water were detected around Indonesia by the TOPEX/Poseidon satellite. The warm, wet air from this water fed the normally heavy rainfall in this region. By August 1997 (right image), sea level had dropped well below average as shown by purple areas (sea level at least 18 centimeters (7 inches) below normal). The warm water had shifted east towards the west coast of North and South America, taking the rains with it. The white and red areas indicate patterns of unusually high 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 movement of warm water away from the western Pacific is tied to the weather-disrupting phenomenon known as El Niño. The departure of the large mass of warm water that is normally located near Indonesia has affected where rain clouds form, altered the typical atmospheric patterns and brought devastating drought to Indonesia. The El Niño phenomenon is thought to be triggered when the steady westward blowing trade winds weaken and even reverse direction. 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 the early indications of El Niño conditions. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov/ |
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TOPEX/El Niño Watch - March
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PIA00734
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - March thru June, 1997 |
| Original Caption Released with Image |
These four views of the Pacific Ocean were produced using sea surface height measurements taken by the U.S./French TOPEX/POSEIDON satellite. The images show sea surface height relative to normal ocean conditions from March 1997 through June 1997. This evolutionary view is providing oceanographers with more convincing information that the weather-disrupting phenomenon known as El Niño is back and getting stronger. 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 surface area covered by the warm water mass is about one and one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21-30 degrees Celsius (70-85 degrees Fahrenheit), is about 30 times the volume of water in all the U.S. Great Lakes combined. 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 the early indications of El Niño conditions. |
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TOPEX/El Niño Watch - Octobe
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PIA00741
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - October 3, 1997 |
| 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 Oct. 3, 1997 as the warm water associated with El Niño (in white) spreads northward along the entire coast of North America from the equator all the way to Alaska. The warm water pool in tropical Pacific resulting from El Niño seems to have stabilized. 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 surface area covered by the warm water mass is about one and one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21 and 30 C (70 to 85 F), carries the amount of heat equal to 100 times the amount of fossil fuel energy consumed by the entire U.S. population during one year. 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 coming winter. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov/ |
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TOPEX/El Niño Watch- Septemb
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PIA00736
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch- September 20, 1997 |
| 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 20, 1997 and provides more convincing information that the weather-disrupting phenomenon known as El Niño is back and getting stronger. 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 surface area covered by the warm water mass is about one and one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21-30 degrees Celsius (70-85 degrees Fahrenheit), is about 30 times the volume of water in all the U.S. Great Lakes combined. 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 the early indications of El Niño conditions. For more information, please visit the TOPEX/Poseidon project web page at http://topex-www.jpl.nasa.gov/ |
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TOPEX/El Niño Watch - El Niñ
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PIA01140
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - El Niño Rhythm, Dec, 10, 1997 |
| 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 Dec.10, 1997 and sea surface height is an indicator of the heat content of the ocean. The volume and area of the warm water pool related to El Niño has increased again after reaching a temporary low around Dec. 1. TOPEX/Poseidon has been tracking the fluctuations of the El Niño warm pool since it began early this year. Oceanographers believe the recent increases and decreases in the size of the warm water pool at the equator are part of the natural rhythm of El Niño and that the warm pool is occasionally pumped up by wind bursts blowing from the western and central Pacific Ocean. Each wind burst has triggered a temporary increase in area and volume of the warm pool. These data collected throughout 1997 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 |
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Pacific Ocean in Holding Pat
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PIA03850
Sol (our sun)
Altimeter
| Title |
Pacific Ocean in Holding Pattern for El Niño |
| Original Caption Released with Image |
The Pacific Ocean doesn't show signs of anything that looks like the whopper El Niño of 1997-1998, according to the latest information from the U.S.-French ocean-observing satellite Topex/Poseidon. The data do show that the mid-equatorial Pacific Ocean has slowly warmed by about 1 degree Celsius (1.8 degrees Fahrenheit) above normal in the past few months. However, the Pacific continues to be dominated by the larger-than-El Niño /La Niña pattern called the Pacific Decadal Oscillation, which may discourage El Niño development."Except for some recent mid-Pacific warming, June 2002 looks very much like June 2001," said oceanographer Dr. William Patzert of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We're still in an E Niño holding pattern." ( See June 2001 image [ http://sealevel.jpl.nasa.gov/elnino/20010621.html ]) The Topex/Poseidon data were taken during a 10-day collection cycle ending June 14, 2002. They show that there hasn't been any fundamental change in the ocean's large-scale patterns for the past three years. The near-equatorial ocean has been very quiet, although sea levels and sea-surface temperatures are near normal or slightly warmer throughout the far western and central tropical Pacific. Red areas are about 10 centimeters (4 inches) above normal, white areas show the sea-surface height is between 14 and 32 centimeters (6 to 13inches) above normal. This warmth contrasts with the Bering Sea, Gulf of Alaska and U.S. West Coast, where lower-than-normal sea-surface levels (blue areas) and cool ocean temperatures continue. The blue areas are between 5 and 13 centimeters (2 and 5 inches)below normal, and the purple areas range from 14 to 18 centimeters (6to 7 inches) below normal. |
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MGS Mars Orbiter Laser Altim
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PIA00960
Sol (our sun)
MOLA
| Title |
MGS Mars Orbiter Laser Altimeter (MOLA) - Mars/Earth Relief Comparison |
| Original Caption Released with Image |
Comparison of the cross-sectional relief of the deepest portion of the Grand Canyon (Arizona) on Earth versus a Mars Orbiter Laser Altimeter (MOLA) view of a common type of chasm on Mars in the western Elysium region. The MOLA profile was collected during the Mars Global Surveyor Capture Orbit Calibration Pass on September 15, 1997. The Grand Canyon topography is shown as a trace with a measurement every 295 feet (90 meters) along track, while that from MOLA reflects measurements about every 970 feet (400 meters) along track. The slopes of the steep inner canyon wall of the Martian feature exceed the angle of repose, suggesting relative youth and the potential for landslides. The inner wall slopes of the Grand Canyon are less than those of the Martian chasm, reflecting the long period of erosion necessary to form its mile-deep character on Earth. |
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MGS Mars Orbiter Laser Altim
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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. |
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MGS Mars Orbiter Laser (MOLA
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PIA00957
Sol (our sun)
MOLA
| Title |
MGS Mars Orbiter Laser (MOLA) Surface Topography of Northern Hemisphere |
| Original Caption Released with Image |
A "picket fence" rendition of surface topography in 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. The profile runs from 73°N to 10°S latitude and passes through the topographically subdued northern plains, the western part of the Elysium volcanic province, which shows 3 miles (5 kilometers) of relief, and the chaotic "dichotomy" boundary between the northern plains and ancient southern highlands. The MOLA profile is approximately 3000 miles (5000 kilometers) long and has a resolution on the surface of 1000 feet (330 meters) and a vertical resolution of approximately 3 feet (1 meter). |
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TOPEX/El Niño Watch - Strong
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PIA02935
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - Strong, Long-lasting La Niña Just Fading Away, June 19, 2000 |
| Original Caption Released with Image |
."Let's not forget that the legacy of two years of La Niña will be with us this summer and into the fall," said JPL oceanographer Dr. William Patzert. "Much of the nation's farmland is really dry in many regions. The reality is that the atmosphere is still acting as though La Niña remains." The National Oceanic and Atmospheric Administration's (NOAA) National Weather Service has forecasted continuing drought for much of the midwestern and southeastern United States and an active hurricane season for our coming summer. NOAA seasonal forecasts can be found at http://www.cpc.ncep.noaa.gov [ http://www.cpc.ncep.noaa.gov ] . The U.S.-French TOPEX/Poseidon mission is managed by JPL for the NASA's Earth Science Enterprise, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. For more information on the TOPEX/Poseidon project, see http://topex-www.jpl.nasa.gov [ http://topex-www.jpl.nasa.gov ], After dominating the tropical Pacific Ocean for more than two years, the 1998-2000 La Niña "cool pool" is continuing its slow fade and seems to be retiring from the climate stage, according to the latest satellite data from the U.S.-French TOPEX/Poseidon mission. These data, taken during a 10-day cycle of collection ending June 9, show that the equatorial Pacific continues to warm up and is returning to normal (green) as this latest, persistent, two-year La Niña episode is coming to an end. Only a few patches of cooler, lower sea levels (seen in blue and purple) remain across the tropics. It should be noted that in June 1999, La Niña barely had a pulse, but was resuscitated in fall 1999. (See June 1999 press release on that topic at http://www.jpl.nasa.gov/elnino/990629.html [ http://www.jpl.nasa.gov/elnino/990629.html ] .) The blue areas are between 5 and 13 centimeters (2 and 5 inches) below normal, whereas the purple areas range from 14 to 18 centimeters (6 to 7 inches) below normal. In the far-western tropical Pacific Ocean, the ocean remains higher and warmer than normal. In summary, it appears that the global climate system is finally emerging from the past three years of dramatic swings from the extra-large El Niño of 1997/1998, which was followed by two unusually cool and persistent La Niña years, according to scientists at NASA's Jet Propulsion Laboratory. But as the northern hemisphere summer begins, above-normal sea surface heights and warmer ocean temperatures (indicated by the red and white areas) still blanket the western equatorial Pacific and much of the north and south mid-Pacific. Red areas are about 10 centimeters (4 inches) above normal, white areas show the sea surface height is between 14 and 32 centimeters (6 to 13 inches) above normal. This contrasts with the Bering Sea and Gulf of Alaska region southward along the western coast of North America, where lower-than-normal sea levels and cool ocean temperatures continue, although this pattern is also weakening. A possible switch in this larger-than-El Niño/La Niña, slower-changing pattern -- the Pacific Decadal Oscillation -- was first noticed by many scientists in late 1998. See a January 2000 press release on that topic at http://www.jpl.nasa.gov/elnino/20000118.html [ http://www.jpl.nasa.gov/elnino/20000118.html ] , or for further information and graphics about the Pacific Decadal Oscillation, see http://topex-www.jpl.nasa.gov/discover/PDO.html [ http://topex-www.jpl.nasa.gov/discover/PDO.html ] |
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TOPEX/El Niño Watch - Los Ni
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PIA02969
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - Los Niños may be Gone, But Pacific Pattern Remains August 14, 2000 |
| Original Caption Released with Image |
After three years of El Niño and La Niña with their often devastating climate consequences, the Pacific is finally calming down in the tropics but still shows signs of being abnormal elsewhere, according to the latest satellite data from the U.S.-French TOPEX/Poseidon mission. These data, taken during a 10-day cycle of collection ending August 17, show that tropical Pacific sea levels, which indicate how much heat is stored in the ocean, have returned to near-normal (green) after three years of dramatic fluctuations. See http://www.jpl.nasa.gov/elnino/ . But as summer ends in the Northern Hemisphere, remnants of the past few years remain embedded in the upper ocean. Above-normal sea surface heights and warmer ocean temperatures (indicated by the red and white areas) still blanket the far-western tropical Pacific and much of the north (and south) mid-Pacific. Red areas are about 10 centimeters (4 inches) above normal, white areas show the sea surface height is between 14 and 32 centimeters (6 to 13 inches) above normal. This contrasts with the Bering Sea and Gulf of Alaska where lower-than-normal sea levels and cool ocean temperatures continue (indicated by blue areas), although this pattern is also weakening. The blue areas are between 5 and 13 centimeters (2 and 5 inches) below normal, whereas the purple areas range from 14 to 18 centimeters (6 to 7 inches) below normal. Looking at the entire Pacific basin, the Pacific Decadal Oscillation's (PDO) characteristic warm horseshoe and cool wedge pattern is still evident in this sea-level height image. The PDO is a long-term ocean temperature fluctuation of the Pacific Ocean that waxes and wanes approximately every 10 to 20 years. Most recent National Oceanic and Atmospheric Administration (NOAA) sea-surface temperature date also clearly illustrate the persistence of this basin-wide pattern. They are available at: http://psbsgi1.nesdis.noaa.gov:8080/PSB/EPS/SST/climo.html."The present calming started three to four months ago when the La Niña faded away," said oceanographer Dr. William Patzert of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "It appears that the global climate system is finally recovering from the past three years of dramatic swings from the extra-large El Niño of 1997/1998, which was followed by two unusually cool and persistent La Niña years.""The good news is that we're finally out from under the El Niño and La Niña of the past three years," Patzert said. "Unfortunately, in the longer term, the reality is that the PDO pattern still dominates the Pacific and, in the short term, the atmosphere is still acting as though La Niña remains. The western United States continues hot and dry, and a larger than normal number of hurricanes are forecast by NOAA for both the Pacific and the Atlantic. Also for the remainder of the summer and into the fall, we are continuing to experience the legacy or hangover from El Niño and La Niña -- the devastating Western U.S. fires from the, Canadian to Mexican borders are one example." National Oceanic and Atmospheric Administration's (NOAA) National Weather Service has forecasted continuing heat in the Western United States and an active hurricane season for the end of summer and into the fall. NOAA seasonal forecasts can be found at: http://www.cpc.ncep.noaa.gov. This month marks the eighth anniversary of the launch of TOPEX/Poseidon, a mission that had been planned to last only three to five years. The satellite has orbited Earth more than 37,400 times and completed 290 10-day data collection cycles. More than 99 percent of all available mission data has been collected and archived by the operations team at JPL. The U.S.-French TOPEX/Poseidon mission is managed by JPL for the NASA's Earth Science Enterprise, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. For more information on the TOPEX/Poseidon project, see http://topex-www.jpl.nasa.gov [ http://topex-www.jpl.nasa.gov ] |
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3000 Mile Laser Altimeter Pr
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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. |
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TOPEX/El Niño Watch - Octobe
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PIA01053
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - October 23, 1997 |
| 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 Oct. 23, 1997 as the warm water associated with El Niño (in white) spreads northward along the entire coast of North America from the equator all the way to Alaska. The warm water pool associated with the El Niño has returned to the volume it was in mid-September after dropping to a temporary low at the beginning of October. The sea surface elevation just north of the El Niño warm pool continues to drop (purple area), enhancing the eastward flowing North Equatorial Counter Current. The intensification of this current is another tell-tale sign of the El Niño phenomenon. This flow contributes to the rise in sea level along the western coasts of the Americas that will progress towards both the north and south poles over the next several months. 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 surface area covered by the warm water mass is about one and one-half times the size of the continental United States. The added amount of oceanic warm water near the Americas, with a temperature between 21-30 degrees Celsius (70- 85 degrees Fahrenheit), is about 30 times the volume of water in all the U.S. Great Lakes combined. 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/ |
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TOPEX/El Niño Watch - "Doubl
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PIA01099
Sol (our sun)
Altimeter
| Title |
TOPEX/El Niño Watch - "Double Peak" Pattern Complete, Dec, 1, 1997 |
| 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 Dec. 1, 1997. The volume of the warm water related to El Niño has receded to about the level it was in early September. Oceanographers note that this El Niño has just completed a classic "double peak" pattern in the eastern Pacific with the first peak in sea level occurring in July and the second peak in October. This pattern is very similar to what was observed during the 1982-83 El Niño, although at that time the double peaks occurred in January and April 1983. After the appearance of the double peaks in 1982-83, the sea level then began falling back to normal levels within a few months. 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 |
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Jason Satellite Observes Mil
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PIA01939
Sol (our sun)
Altimeter
| Title |
Jason Satellite Observes Mild El Nino in 2006 |
| Original Caption Released with Image |
In September 2006, NASA satellite data indicated that El Niño had returned to the tropical Pacific Ocean, although it was relatively weak. As of early October, scientists were not sure if the event would persist, and it was much less intense than the last major El Niño episode, which happened in 1997-1998. That event brought devastating floods to California that cost millions of dollars in damage while severe drought struck Indonesia, Australia, and the Philippines. Among the ocean characteristics that signal developing El Niño events is a change in average sea surface height compared to normal sea level. When water warms, it expands a little, which changes its volume slightly. When heat begins to build up in the Pacific during an El Niño event, the sea surface height begins to creep up. NASA observes changes in average sea surface height using its Jason satellite. The image is based on the average of 10 days of data centered on September 15, 2006, compared to the long-term average of observations from 1993-2005. In this image, places where the Pacific sea surface height is higher (warmer) than normal are yellow, orange, and red, and places where the sea surface is lower (cooler) than normal are blue and purple. Green shows where conditions are near normal. The swath of red in the center of the scene reveals that an El Niño was in progress when Jason observed the Pacific. El Niño is a cyclical warming of the ocean waters in the central and eastern tropical Pacific that generally occurs every 3 to 7 years. It is linked with changes in air pressure and high-level winds that can affect weather worldwide. Typically peaking during the Northern Hemisphere winter months, El Niño is the warm phase of the El Niño/Southern Oscillation. It alternates with La Niña, the cooling of ocean waters in the same region of the Pacific. According to Bill Patzert, oceanographer and climatologist at NASA's Jet Propulsion Laboratory, "The present conditions indicate that the intensity of this El Niño is too weak to have a major influence on current weather patterns. But, if the ocean waters continue to warm and spread eastward, this event would likely strengthen, perhaps bringing much-needed rainfall to the southwestern and southeastern United States this winter." The Jason satellite carries a dual-frequency radar altimeter. This instrument beams microwave pulses-at 13.6 and 5.3 Gigahertz, respectively-downward toward the Earth. To determine the ocean's height, the instrument precisely measures the time it takes for the microwave pulses to bounce off the surface and return to the spacecraft. This measure, multiplied by the speed of light, gives the range from the satellite to the ocean surface. The joint U.S.-French Topex/Poseidon mission is managed by the JPL for NASA's Science Mission Directorate, NASA Headquarters, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. Research on Earth's oceans using Jason and other, space-based capabilities is conducted by NASA's Science Mission Directorate to better understand and protect our home planet. For more information on NASA's ocean surface topography missions, see http://sealevel.jpl.nasa.gov/ [ http://sealevel.jpl.nasa.gov/ ] or to view the latest Jason data see http://sealevel.jpl.nasa.gov/science/jason1-quick-look/ [ http://sealevel.jpl.nasa.gov/science/jason1-quick-look/ ]. |
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MGS MOC Coverage of Mars Pol
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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 ] |
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