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The new ICESat-2, to be launched Saturday, can measure changes in the ice of the planet less than the width of a pencil.
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If all goes well for NASA on Saturday, climatologists will have a new eye in the sky that will be able to observe the melting of the Earth's ice. virtually drip drip.
O.K., not exactly. The new satellite, called ICESat-2, will allow researchers to examine glacially, ice-caps and sea-ice, which constitute most of the frozen regions of the Earth, with the utmost accuracy. This melting ice contributes to sea level rise, and ICESat (an imperfect acronym for Ice, Cloud and Land Elevation Satellite) will provide important information on the speed at which it occurs.
NASA is expected to launch the satellite from Vandenberg Air Force Base in California at 5:46 Pacific Time or 8:46 am Eastern Time. The agency will show the launch live on NASA.com.
As it is ICESat-2, you know there was a previous ICESat: it was launched in 2003 and has been running until 2009. Since then, NASA has taken action planes flying over Greenland and Antarctica, a interim program called Operation IceBridge that cost about $ 15 million a year.
NASA does not simply replace the old ICESat. A lot of the cost of ICESat-2, which is about $ 1 billion, was used to create a much more powerful instrument.
The old satellite measured the elevation of terrestrial ice with a single laser beam; the new gizmo has six, shooting 10,000 times a second. All these pulses of light will give this satellite astonishing precision. While the previous satellite took measurements spaced along the length of a football field in each end zone, the new satellite measured the distance between each line of land.
NASA says it will be able to measure the change in elevation of the icecaps of Antarctica and Greenland to about one-sixth of an inch, less than the width of a pencil.
The satellite instrument, called Advanced Laser Altimetry System, or Atlas, Measure the height of forests to determine the amount of vegetation in a region and monitor other attributes of land surfaces, water and clouds.
By accurately measuring the altitude of the Earth's ice, Atlas and ICESat-2 will help scientists better understand the amount and speed of ice melting in a warming world.
We already know that melting occurs in huge freshwater reserves locked in the ice caps of Greenland and Antarctica increases the level of the sea by one millimeter a year, representing one-third of the total increase. (The remaining glaciers and ice caps represent another third and the rest can be attributed to the fact that ocean warming is increasing in volume.) A deeper and more accurate understanding of the melt will help to better understand the elevation. sea level.
And even though melting ice floating in the oceans does not add to sea level rise, measuring the height of this ice will also illuminate the effects of fresh water on things like ocean currents.
Tom Neumann, assistant researcher for the new satellite, said it would provide "a phenomenal picture" of changes in the ice sheets and the water of the planet. "This will allow scientific breakthroughs in the cryosphere and polar research for years to come," he said.
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John Schwartz is part of the climate team. Since joining The Times in 2000, he has covered science, law, technology, the space program and more, and has written for almost all sections. @jswatz • Facebook
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