2000 EARTH SCIENCE VIDEOTAPES |
| |
Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| THE YEAR IN EARTH SCIENCE 1999 | G00-008 | 04/17/00 | 00:53:07 | A dramatic year in earth science ended with the successful deployment of Terra in late December. Managed by the Goddard Space Flight Center, Terra is NASA's next generation flagship of earth observing satellites. In literary terms, it is both a prologue and epilogue, pointing to the future while punctuating the rich science undertaken throughout the past year. During 1999 the Pacific twins El Nino and La Nina kept terrestrial researchers busy. Fewer hurricanes than normal cropped up in the Atlantic, but their effects were anything but minor. New radar maps of Antarctica continue to yield enormous gains in our understanding of the southernmost continent and its relationship to the rest of the globe. Researchers heard raindrops in a new way, and the final Landsat satellite climbed to orbit, where it again proved the value of its extraordinary legacy dating back to 1974. Editorial Note: In the following video collection, stories have been grouped together in terms of related topics rather than in overall chronological order. Numbers following each headline correspond to library numbers in the Goddard Television video archive.
|
TAPE CONTENTS: |
| ITEM (1): Retreat Of The Western Antarctic Ice Sheet (G99-004)
Animation of Retreating Ice -The animation begins with Antarctica as it is today, then morphs to depict changes in the Antarctic ice sheet since the peak of the last ice age nearly 20,000 years ago. The animation then morphs again to show current conditions. The West Antarctic ice sheet has lost nearly 2/3 of it's mass during this period - a volume sufficient to raise sea level 33 feet.
Close-up of Retreating Ice - Morph shows changes in Antarctic ice sheet from 20,000 years to present day. Various views.
|
| ITEM (2): Researchers Document Rapid Thinning of Greenland's Glaciers (G99-016)
(1) Rapid Thinning of the Greenland Ice Sheet - A study of Greenland indicates a rapid thinning of glaciers along the east coast of the southern half of the island, suggesting that the lower elevation portion of the ice sheet may be particularly sensitive to changes in climate. This is the first evidence of widespread thinning of low-elevation parts of one of the great polar ice sheets. Areas of ice thinning are shown in blue, areas where ice is thickening are shown in orange.
(2) Collecting The Data - In 1993 and 1994, NASA researchers surveyed the Greenland ice sheet using an airborne laser altimeter. Ten flight lines flown in 1993 in southern Greenland were resurveyed in 1998. Scientists used computers to create detailed maps of changes in the ice.
|
| ITEM (3): Radarsat Maps Antarctica (G99-080)
(1) Continental Tour - Antarctica is the coldest, windiest, driest, and on average highest continent. While over 97 percent of the continent is ice covered, its surface is remarkable diverse. Glaciers plow through 15,000 ft. mountain ranges, rising above the land like citadel spires. Fields of crazed ice stretch out as far as the eye can see. Icebergs the size of New England States calve from walls of floating ice that are themselves as big as Texas.
(2) Lake Vostok - More than two miles beneath the icy cloak shielding Antarctica from the sky hides a massive fresh water lake. Seen from RADARSAT, the lake appears as a flat plain surrounded by the sandpaper of craggy ice. As the topographical ice sheet flows over the subglacial lake, surface features smooth out.
(3) Larsen Ice Shelf - In 1978, scientists predicted that global warming would lead to a disintegration of Antarctic Peninsula ice shelves. Spaceborne data indicate that this prediction may be coming true. In these before and after images, note the dramatic change in the apparent shoreline. Scientists captured the first image in using the ERS-1 satellite in 1992. As seen in the second image, collected by RADARSAT in 1997, huge changes have come to the coastline.
(4) Fimbul Ice Shelf - The Fimbul Ice Shelf has remained relatively consistent in its appearance for the last thirty years, but researchers are paying close attention to changes. Ice shelves are considered to be particularly sensitive to climatic changes and scientists have detected a marked retreat of several along the Antarctic Peninsula. Note the fascinating formations along the Fimbul, believed to be the product of glacial ice flowing over rocky outcroppings and islands.
|
| ITEM (4): Radarsat Maps Slow Motion White Water Rivers (G99-099)
(1) Snowdunes - Radarsat also enabled researchers to gain a better understanding about a surface feature found only at the bottom of the world. These snow dunes are believed to be highly stable waves of graded ice grains, nearly impossible to see without the aid of satellite remote sensing systems, and larger than the state of California. Stretching for hundreds of kilometers, these dunes rise only 2 to 3 meters but may have a periodicity of more than 2 kilometers.
(2) West Antarctic Ice Streams - Over a twenty-four day span, scientists used two images over identical regions of Antarctica in a technique called interferometry. Their comparative analysis of the images helped develop the following ice stream animations on the west side of the continent, showing flow rate and direction to an extent never before possible.
(3) How they Work: A Virtual Model of Ice Streams (Animation) - Experts still aren't positive how ice streams actually work. The current theory says that tributaries of slower ice come together to create larger streams, often at points where elevation and terrain act as a slight funnel. The convergence then literally slides on a lubricated bed of oceanic muck covered by a millimeter thin layer of water, gaining strength as they drive toward the ocean.
|
| ITEM (5): Amazing Changing Ocean: Moderate La Nina May Persist Through Spring (G99-011)
(1) La Nina Hangs on Longer than Expected - Ocean surface temperatures plummeted 15 degrees (F) and sea elevation dropped two feet from the peak of the El Nino to the peak of the La Nina in some regions in the eastern Pacific. Red indicates warmer than normal ocean surface temperatures and blue indicates cooler temperatures. Sea height data comes from the NASA/CNES TOPEX/Poseidon radar altimeter. Sea surface temperature data from NOAA NCEP SST analysis.
(2) Quick Change ? La Nina Breaks Through - Water temperatures west of the Galapagos Islands dropped an unprecedented 10 degrees (f) in just over a week in June 1998. The cooler temperatures hastened the demise of El Nino and brought about a rapid transition to La Nina that surprised scientists. Red indicates warmer than normal temperatures, and blue indicates cooler than normal temperatures.
(3) World Wide Climate Changes - Animation illustrates how El Nino and La Nina drive global climate changes. As warm water in the tropical Pacific shifts its location one-third of the way around the globe, this major source of heat changes the position of atmospheric high and low pressure centers. This causes changes in the position of the jet streams hitting North America and associated temperature and rainfall patterns. The jet stream location is critical for steering storms into the continental U.S.
(4) The Hurricane Connection - La Nina tends to enhance the formation of hurricanes, while El Nino tends to suppress the formation. During El Nino, the subtropical jet is displaced southward toward hurricane generation areas in the Atlantic. The quick moving air aloft tends to blow the top off the developing clouds in a hurricane, inhibiting full growth of the system and decreasing the number of hurricanes making North American landfall.
|
| ITEM (6): Rebound From El Nino (G99-017) -
El Nino also has a dramatic impact on the global biosphere. Satellite instruments measuring ocean color monitor chlorophyll concentrations. These measurements help scientists monitor changes in phytoplankton, the lowest level of the marine food chain. During El Nino, an upwelling of nutrients in colder water is suppressed with often disastrous implications for marine ecosystems. NASA's SeaWiFS instrument enabled scientists to witness the ocean transition from El Nino (first image) to La Nina (second image) conditions in the equatorial Pacific. The cooler, upwelled nutrient-rich waters associated with the demise of El Nino and the transition to La Nina initiated a huge plankton bloom along the equator.
|
| ITEM (7): An Immense Pacific Bloom (G99-100) -
This sequence illustrates the vast size and intensity of the ocean's biological rebound from El Ni–o. Satellite imagery from NASA's Sea-viewing Wide-Field-of-view Sensor (SeaWiFS) instrument showed nearly a complete lack of plankton along the equatorial Pacific during El Ni–o. The cool waters associated with La Ni–a brought nutrients from the below the surface and enabled an enormous plankton bloom(shown in green).
|
| ITEM (8): KWAJEX
Resource Tape (G99-075)
(1) A Cloud Cross-Section (Animation) - To measure a cross section of the atmosphere, three aircraft fly in a sandwich formation. A DC-8 cruises the top of the clouds, a Convair measures the middle cloud region where lots of ice crystals are found, and a Citation gets measurements at the lower level. The ground track of the TRMM satellite passes within 250 km of radar facilities on Kwajalein Island approximately 22 times per month. Optimal measuring conditions allow for the three planes and the satellite to line up and collect data from the same vertical position.
(2) Small Raindrop (Animation) - When a small raindrop falls on the ocean, it produces sound from its impact with the surface and, more importantly, by creating a bubble that gets trapped underwater. Different raindrop sizes produce distinctive sounds. When recorded underwater, small raindrops make a hissing sound. The animation is shown at two speeds, the second slowed down to demonstrate the distinct sound of impact and the subsequent ring of higher frequency sounds made by the bubble
(3) Large Raindrop (Animation) - For large and very large raindrops, the splash becomes energetic enough to create a wide range of bubble sizes trapped underwater, which produces a loud sound relatively low in frequency. The animation is shown at two speeds, the second slowed down to demonstrate the distinct sound of impact and the subsequent ring of lower frequency sounds made by the bubble.
|
| ITEM (9): LANDSAT 7 Launch (G99-031) - LANDSAT 7 launched at 2:32 p.m., April 15, from Vandenberg Air Force Base, CA, on a Delta II rocket.
|
| ITEM (10): LANDSAT 7 (Animation) (G99-019) -
Landsat 7 is the latest in a series of Earth observing satellites that have provided remotely sensed observations of the Earth's land surface and coastal regions for over 26 years. Landsat 7 marks a new direction in the program to reduce the costs of data and increase global coverage for use in global change research. Analysis of the data will provide scientists with new information on deforestation, receding glaciers and crop monitoring.
|
| ITEM (11): The Layers of San Francisco (G99-021) - By combining different spectral bands from the ETM+ camera, researchers can produce images highlighting different features of the land. Landsat 7 not only has detectors calibrated to see visible light -- blue, green, and red -- but it also looks into areas we cannot see, in the near- and short-wave infrared. The natural color wavelength regions can be redisplayed similar to a photograph, while those regions we cannot see are assigned colors to make them visible.
|
| ITEM (12): Views of American Cities (G99-021) -
For over 26 years, Landsat images have been used to help urban planners understand where growth is taking place and help geographers evaluate how different urban planning programs effect population growth and land use. These images were captured using Landsat Thematic Mapper bands 5, 4, and 2 mapped to red, green, and blue respectively. Cities includeAtlanta, Boston, Denver, Detroit, New York, and Phoenix.
|
| ITEM (13): SeaWiFS California Fire Images (G99-056) - These two sequences show fires raging in Northern California. The images were captured at 1:40 p.m. (PDT) on August 25, 1999, by NASA's Sea Viewing Wide Field-of-View Sensor (SeaWiFS) on the SeaStar satellite. These sequences were enhanced and rendered at the Scientific and Visualization Studio (SVS) at NASA's Goddard Space Flight Center, Greenbelt, MD.
|
| ITEM (14): Measuring Giant Trees (G99-074)
(1) Mapping From The Air - The new LVIS (laser vegetation imaging sensor) onboard NASA's C-130 aircraft operates by senting pulses of energy to the ground, then analyzing the signal as the pulses reflect from leaves, branches and the terrain. It is able to measure the height of the forest canopy and each tree within it, as well as the amount of vegetation in the forests.
(2) Measuring Tree Texture - This is an image of the Costa Rican rainforest illustrating elevation and vegetation taken by a LIDAR aircraft during a fly-over last year. It dissolves into a tree-colored image showing LIDAR's potential for generating three-dimensional images of the forest.
(3) Mapping in False Color - The same technology that mapped the topography of Mars will measure the height and amount of vegetation in California's sequoia forest as well as eastern U.S. forests in Maryland, North Carolina, and New Hampshire. The images will be similar to this one, taken last year from a fly-over of the Costa Rican rainforest. Red represents the tallest elevations and blue the lowest.
|
| ITEM (15): Floyd's Carolina Floods:
A Natural Disaster Becomes Research (G99-085)
(1) Sedimentation Along The Coast - SEAWiFS took the following images over a period of weeks in late summer and early fall. The sequence begins prior to the storm season. Then Hurricane Floyd appears, grinding into the Carolina coast. Following Floyd, notice how the images show dramatic changes of color in the waterways as they flow toward the ocean. This is particularly visible around Cape Hatteras; the dark mass of water there is sediment trapped by the barrier islands. SeaWiFS is designed to look at ocean color specifically. In the case of these changes to the coast of North Carolina, the instrument is particularly useful in detecting system wide changes to the environment.
Image Sequence Chronology:
September 16: Hurricane Floyd
September 17: The Day after Floyd
September 23: Early Flooding
October 26: Late Flooding, Sedimentation
(2) Landsat Sees Sedimentation - From space, Landsat 7 captures the massive flow of sedimentation and waste runoff in the area most affected by flooding. Notice the dark coloration in the engorged waterways, indicating heavy concentrations of organic material that's been washed into the water system.
(3) Pamlico River Flooding -In the following image, notice how the Pamlico River swells far past its banks due to heavy rains. The sequence starts with an image prior to the flood taken on July 7th. The second image comes from September 23rd, following Hurricanes Floyd and Irene.
|
| ITEM (16): Satellite Aids Scientists in Forecasting Severe Weather (G99-A028)
(1) GOES-L Spacecraft Animation - After parking in geostationary orbit, GOES-L, now called GOES-11, was put in standby mode to provide continuous service and quick replacement when it is needed to replace
either the GOES 8 or GOES 10 satellite.
(2) Hurricane Mitch Approaches The Mexican Coastline - The images were taken 26-27 October 1998 by the NOAA/National Weather Services' Geostationary Operational Environmental Satellite (GOES)-8. The video was enhanced and rendered at the NASA Goddard Space Flight Center, Laboratory for Atmospheres.
(3) Hurricane George -This animation shows the path of Hurricane Georges as it moved through the Caribbean and the Gulf of Mexico. The images were collected September 21-29, 1998 by the NOAA/National Weather Services Geostationary Operational Environmental Satellite (GOES)-8. The video was enhanced and rendered at the NASA Goddard Space Flight Center, Laboratory for Atmospheres.
|
| ITEM (17): Oklahoma Tornadoes(G99-A028) - These images generated from GOES 8 data show killer tornadoes over Oklahoma City, Oklahoma. The satellite collected the data May 3, 1999.
|
| ITEM (18): Hurricane "CAT Scan" 3-D Images Probe Inner Secrets of Super Storms (G99-045)
(1) Hurricane "CAT" Scans - Using the world's only spaceborne rain radar, aboard the TRMM spacecraft, scientists create 3-D views of rain inside powerful hurricanes. Red indicates precipitation in excess of 2 inches per hour. The following sequences are of Hurricane Mitch (10/27/98), Hurricane Georges (9/27/98), and Hurricane Earl (9/2/98).
(2) Miracle Swath - TRMM captured this dramatic view of four storms -- remnants of tropical storm Howard, Hurricane Isis, Hurricane Earl, Hurricane Danielle -- in a single pass on September 2, 1998.
(3) Hurricane Bonnie - While monitoring the progress of one of last years most dramatic hurricanes using the TRMM spacecraft, researchers obtained compelling images of Hurricane Bonnie showing a cumulonimbus storm cloud towering like a 59,000 foot sky scraper. This new view of "hot towers" in hurricanes could help forecasters predict storm behavior. The image was taken 8/22/98.
(4) Hurricane Engine Animation - TRMM's unique combination of passive and active microwave instruments can peer inside cloud systems and measure rainfall. TRMM allows scientists to study the combustion process in the hurricane engine and relate this process to intensification or weakening of a storm, as shown in the following animations.
(5) Hurricane Peel Away - Hurricanes can be compared to huge engines which convert heat from tropical oceans and atmosphere to wind and waves. To better understand what powers the hurricane engine, scientists need to take a closer look at the mechanisms that strengthen or weaken hurricanes.
(6) Hurricane Energy Process - As water vapor evaporates from the warm ocean surface, it is forced upward in towering convective clouds in the eyewall and rain band regions of the storm. As the water vapor changes from a gas to a liquid, the storm releases latent heat.
(7) Cloud Growth - The release of latent heat warms the surrounding air, making it lighter, which promotes more vigorous cloud development. It is suspected that rapid bursts of cloud growth, particularly in the eyewall region of hurricanes, may relate to the intensification phase of a storm. Towering eyewall clouds are potential precursors to intensification of hurricanes.
|
| ITEM (19): Hurricane Dennis (G99-056) - This animation shows the relative position of Hurricane Dennis. Red indicates rain rates in excess of 2 inches per hour. This image was recorded August 27, 1999, by the TRMM spacecraft.
|
| ITEM (20): TRMM Animation (G99-045) - TRMM is a joint U.S.-Japanese mission, the first Earth science mission dedicated to studying tropical and subtropical rainfall. Tropical rainfall, falling within 35 degrees north and 35 degrees south of the equator, comprises more than two-thirds of global precipitation. TRMM was launched on Nov. 27, 1997, from Tanegashima, Japan, and has produced continuous data since Dec. 8, 1997.
|
| ITEM (21): 1999 Antarctic Ozone Low Smaller Than Last Year - (G99-073B)
(1) 1999 Antarctic Ozone "Hole" - This time lapse animation shows the evolution of the 1999 Antarctic ozone low which covered 9.8 million square miles on Sept. 15. The record area of Antarctic ozone depletion of 10.5 million square miles was set on Sept. 19, 1998. The Antarctic ozone low develops each year between late August and early October.
(2) A Unusual Sidekick - This year's study found that a second ozone "low" had formed between New Zealand and Antarctica on Sept. 17. This sort of ozone low is a result of the redistribution of ozone by a large weather system. The secondary low ozone region moved eastward along the rim of the main Antarctic low for a number of days after Sept. 17.
(3) How Ozone Protects - Ozone protects the Earth by absorbing harmful ultraviolet radiation. The ozone molecule is split into one free oxygen atom and one molecule of ordinary oxygen. The free oxygen usually reacts with another oxygen molecule to reform a new ozone molecule.
(4) Ozone Destruction - Chlorofluorocarbons (CFCs) lead to destruction of the protective ozone molecules located in the stratosphere. Chlorine atoms liberated from CFCs steal oxygen atoms, thus destroying the protective ozone molecule. One chlorine atom can destroy many thousands of ozone molecules over its lifetime in the stratosphere. The ozone low appears because of the normally very cold Antarctic winter conditions.
|
| ITEM (22): Biomass Burning and Weather (G99-078)
(1) Inhibited Rain In Borneo: Satellite Data Confirms
Observations - The Indonesian island of Borneo falls directly in the observational path of the research instruments. By measuring the amount of smoke and other aerosols above a given region, and matching that data with measurements regarding specific amounts of rainfall, researchers have concluded a distinct cause and effect relationship between aerosols and rainfall.
(2) How Smoke Inhibits Rainfall: Normal Conditions - Under normal conditions, tropical clouds swell with water droplets. Those droplets have a tendency to clump together, thus increasing their weight relative to the surrounding cloud. As they coalesce, they fall out of the cloud as rain.
(3) How Smoke Inhibits Rainfall: Smoky Conditions - In areas of concentrated biomass burning, water condenses around tiny particles of smoke, called nuclei. These nucleated drops tend not to clump together, remaining trapped in the cloud, inhibiting rainfall. From space, heavily nucleated clouds appear brighter due to the fact that there are more free floating, smaller water particles available to reflect and scatter light.
(4) How Smoke Inhibits Rainfall: Comparison Of Conditions - In this animation, compare the two systems side by side. You can see how
the rain producing cloud on the left is composed of larger water droplets, making it easier for them to coalesce and fall out as precipitation. On the right, notice how the smaller nucleated particles tend to remain apart, without forming larger drops. This smoke affected cloud will not produce rain.
(5) Satellite Data Dissolve Sequence - Readings from the TOMS (Total Ozone Mapping Spectrometer) satellite measured aerosol levels above Borneo throughout February 1998. Red represents fires and hot spots. Clouds and smoke next appear. Note the heavy stripes of smoke toward the right and upper right of the image. Light blue notes concentrations of water droplets, while dark blue marks areas with precipitation. Notice how there are no indications of rain near the island hot spots and smoky regions.
|
| ITEM (23): TERRA Launch (G99-108) - This is the launch of the TERRA spacecraft from Vandenburg AFB Dec.18, 1999.
|
| ITEM (24): New Eyes On Earth: Terra (G99-B088)
(1) TERRA, The EOS Flagship - Terra leads the way among NASA's Earth Observing System (EOS) satellites. It's part of a precedent setting program designed to provide daily information on the health of the planet. Terra is the most comprehensive tool ever launched for scientific studies of the Earth.
(2) TERRA Looks Closely at Earth - The five instruments on Terra are MODIS, MISR, ASTER, MOPITT AND CERES. By scaning the Earth for a variety of features the collection of instruments will take the daily pulse of the planet.
|
TR>
ITEM (25): An Observatory Aimed at Home- Terra Sees Earth Anew (G00-028)
(1) MODIS (MODerate resolution Imaging Spectroradiometer) - In science, color is information. MODIS collects images of the Earth's surface, reading the various spectra (or color) of reflected radiation from different points on the globe . Primary MODIS investigations include the study of surface temperature (including fire detection), ocean sediment and phytoplankton concentrations, vegetation maps, pollution, snow cover, and more.
(2) MISR (Multi-angle Spectroradiometer) - MISR is unique. A series of nine cameras, each pointed at a different angle, looks at a the same slice of the Earth from a different perspective. The cameras make their observations in four wavelengths of light: blue, green, red, and near-infrared. MISR can determine both how sunlight behaves and interacts with Earthâs environment.
(3) ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) - ASTER is a collaborative effort between NASA and the Japanese Ministry of International Trade and Industry. It's designed primarily to collect data based on the reflection and absorption of heat from the planet below. With its ability to generate stereoscopic images, ASTER will be able to create digital elevation maps.
(4) MOPITT (Measurements of Pollution in the Troposphere) - MOPITT's main purpose is to measure carbon monoxide and methane levels in the lower atmosphere. Various sources of these gases include industrial zones, herds of cattle, decomposition of biomass, and others. By studying where atmospheric gasses are concentrated, how they behave, and how they form, scientists hope to gain a better understanding about how atmospheric pollution interacts and affects the environment.
(5) CERES (Clouds and the Earth's Radiant Energy System) - CERES looks at clouds. More specifically, CERES studies the radiation balance on Earth--how much heat is absorbed and reflected in different areas. By looking at how different cloud formations absorb or reflect various amounts of energy, scientists can develop new predictive models about weather systems and how the Earth maintains its delicate temperature balance.
|
Earth Science Gallery