2000 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| RESEARCH SUGGEST DYNAMIC FORCES AT WORK IN ARCTIC ICE
| G00-016 | 03/28/00 | 00:07:15 | Despite its image as a static, frozen wasteland, the dynamic ice pack above the Arctic Circle plays an important role in regulating the Earth's climate. That's the focus of research conducted at NASA's Laboratory for Hydrospheric Processes at the Goddard Space Flight Center. Unlike Antarctica, the ice covered continent capping the South Pole, there is no land covering the North Pole. But study of the northern pack ice shows that it's not only more complex than initially thought, but also highly influential in the health of the planet.
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TAPE CONTENTS: |
| ITEM (1): Ice Concentration Maximums and Minimums - Research and data collection of Arctic Ocean isn't easy. But using data collected by a number of different satellites from 1978-1998, scientists have been able to stitch together a quality controlled record of sea ice in that part of the world . The first visualization displays average ice concentrations in March, the seasonal maximum; the second visualization shows the seasonal minimum, with measurements taken in September.
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| ITEM (2): Charting Change in a Computer - This visualization shows 120-year slice of that complete model, essentially offering a research window onto experimental processes that require longer time frame than human lifetimes. According to this model, developed by NOAA's Geophysical Fluid Dynamics Laboratory, projecting a period from 1940 to 2060, there is evidence to suggest that human factors have had a measurable effect on Arctic ice decreases.
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| ITEM (3): The Dynamic Ice Pack - The northern pack is a dynamic and complex environment, showing seasons much like the rest of the world. In spring and summer, the northern ice pack shrinks, and in the autumn and winter it grows. The scientists on this project used observations of seasonal changes in the ice to determine if biannual averages were changing over time. In this visualization, 365 daily measurements of ice concentration are shown for the year 1998.
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| ITEM (4): Ice Concentration - Changes Over Time - Over a nineteen- year period, the total concentration of ice over the northern part of the globe has decreased, but just slightly. At first glance this visualization appears to be a simple quantitative comparison of North Pole ice over time. On fact it is more subtle. This visualization shows comparative concentration, that is, how much area is covered by ice. It does not compare total amount of ice, nor thickness, nor density. Concentration in this case refers to amount of continuous ice versus open water visible from space. In these images, blue represents where ice concentrations were higher in 1979, while red represents where ice concentrations were higher in 1998.
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| ITEM (5): Reflectivity and Heating The Global Role of the Polar Caps - The polar caps not only hold much of the planet's total fresh water, but also play an important role in regulating the Earth's temperature. The relevant characteristic is called albedo. It's a measure of how much radiation, or light, is reflected from a body. Were the ice caps to appreciably recede, sunlight that otherwise would have been reflected back into space would get absorbed by the darker, denser mass of ocean and land beneath.
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| ITEM (6): Melting Icebergs - This animation provides a more close-up perspective of the relationship between ice and solar reflectivity. As glaciers, the polar caps, and in this case, icebergs melt, less sunlight gets reflected into space. It is instead absorbed into the oceans and land, thus raising the overall temperature and adding energy to a vicious cycle.
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| ITEM (7): Selected Soundbites With Dr. Claire Parkinson, Arctic Ice Researcher
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