From the AGU
Undertaking utilized 25 years of information from six worldwide satellite tv for pc missions
29 July 2019
WASHINGTON — Constructed from 1 / 4 century’s price of satellite tv for pc information, a brand new map of Antarctic ice velocity by glaciologists from the College of California, Irvine and NASA’s Jet Propulsion Laboratory is probably the most exact ever created.
Revealed as we speak in a brand new paper within the AGU journal Geophysical Analysis Letters, the map is 10 occasions extra correct than earlier renditions, masking greater than 80 % of the continent.
“By using the complete potential of interferometric section alerts from satellite tv for pc synthetic-aperture radars, now we have achieved a quantum leap within the description of ice move in Antarctica,” stated lead creator Jeremie Mouginot, UCI affiliate researcher in Earth system science. “This extra detailed illustration will assist enhance our understanding of ice habits below local weather stress over a bigger a part of the continent, farther south, and can allow improved projections of sea degree rise via numerical fashions.”
To chart the motion of ice sheets throughout the floor of the big land mass, the researchers mixed enter from six satellite tv for pc missions: the Canadian Area Company’s Radarsat-1 and Radarsat-2; the European Area Company’s Earth distant sensing satellites 1 and a pair of and Envisat ASAR; and the Japan Aerospace Exploration Company’s ALOS PALSAR-1.
Whereas the information had been unfold throughout 25 years, the tempo of sign gathering accelerated within the final decade as extra assets had been deployed within the Earth’s orbit. As ice sheet science coordinator within the World Meteorological Group’s Polar Area Job Group, co-author Bernd Scheuchl, UCI affiliate challenge scientist in Earth system science, was liable for buying the related information from the assorted worldwide house businesses.
Earlier mapping efforts relied closely on “function” and “speckle monitoring” strategies, which detect the delicate movement of parcels of ice on the bottom over time; this strategy has been confirmed efficient in estimating ice move pace. To measure considerably slower ice sheet motion within the huge inside areas, the UCI staff augmented these strategies with synthetic-aperture radar section interferometry, which detects the delicate movement of pure reflectors of radar alerts in snow/ice unbiased of the dimensions of the parcel of ice illuminated by the radar.
“The interferometric section of SAR information measures the ice deformation sign with a precision of as much as two orders of magnitude higher than speckle monitoring,” Mouginot stated. “A disadvantage is that it requires much more information, specifically a number of passes at completely different angles over the identical level on the bottom – an issue that was solved by a consortium of worldwide house businesses pointing Earth-monitoring spacecrafts to this a part of the world.”
The staff was capable of compose a map that resolves ice motion to a degree of 20 centimeters (somewhat over half a foot) per yr in pace and 5 levels in annual move path for greater than 70 % of Antarctica. It’s the primary time that high-precision mapping of the inside areas has been completed.
“This product will assist local weather scientists obtain a variety of objectives, reminiscent of a greater willpower of the boundaries between glaciers and an intensive analysis of regional atmospheric local weather fashions over the whole continent,” stated co-author Eric Rignot, chair and Donald Bren Professor of Earth System Science at UCI and a JPL senior analysis scientist.
“It’ll additionally assist in finding probably the most promising websites for ice core drilling to extract local weather data and in analyzing the mass stability of Antarctica past its periphery.”
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