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Author Topic: The Randolph Glacier Inventory, RGI  (Read 1864 times)

AbruptSLR

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The Randolph Glacier Inventory, RGI
« on: September 13, 2014, 05:43:04 PM »
The linked reference (with an open access pdf) discusses the Randolph Glacier Inventory (RGI), which is the most complete collection of digital outlines of glaciers around the world:

Pfeffer, W. Tad; Arendt, Anthony A.; Bliss, Andrew; Bolch, Tobias; Cogley, J. Graham; Gardner, Alex S.; Hagen, Jon-Ove; Hock, Regine; Kaser, Georg; Kienholz, Christian; Miles, Evan S.; Moholdt, Geir; Mölg, Nico; Paul, Frank; Radić, Valentina; Rastner, Philipp; Raup, Bruce H.; Rich, Justin; Sharp, Martin J. (20140, "The Randolph Glacier Inventory: a globally complete inventory of glaciers", Journal of Glaciology, Volume 60, Number 221, June 2014, pp. 537-552(16)


http://www.ingentaconnect.com/content/igsoc/jog/2014/00000060/00000221/art00012


Abstract: "The Randolph Glacier Inventory (RGI) is a globally complete collection of digital outlines of glaciers, excluding the ice sheets, developed to meet the needs of the Fifth Assessment of the Intergovernmental Panel on Climate Change for estimates of past and future mass balance. The RGI was created with limited resources in a short period. Priority was given to completeness of coverage, but a limited, uniform set of attributes is attached to each of the ∼198 000 glaciers in its latest version, 3.2. Satellite imagery from 1999–2010 provided most of the outlines. Their total extent is estimated as 726 800±34 000 km2. The uncertainty, about ±5%, is derived from careful single-glacier and basin-scale uncertainty estimates and comparisons with inventories that were not sources for the RGI. The main contributors to uncertainty are probably misinterpretation of seasonal snow cover and debris cover. These errors appear not to be normally distributed, and quantifying them reliably is an unsolved problem. Combined with digital elevation models, the RGI glacier outlines yield hypsometries that can be combined with atmospheric data or model outputs for analysis of the impacts of climatic change on glaciers. The RGI has already proved its value in the generation of significantly improved aggregate estimates of glacier mass changes and total volume, and thus actual and potential contributions to sea-level rise."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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AbruptSLR

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Re: The Randolph Glacier Inventory, RGI
« Reply #1 on: October 16, 2014, 11:16:54 PM »
The linked reference (see extract below) indicates that the glaciers of the Karakoram region of Asia are expanding.  As the rate of SLR is not slowing down, this implies that the combined SLR contribution from Greenland and Antarctica are almost certainly accelerating:
http://www.livescience.com/48256-asia-karakoram-glaciers-stability.html

Extract: "Glaciers around the world are melting, retreating and even vanishing altogether. But in the mountainous Karakoram region of Asia — home to K2, the second-highest peak on Earth — the glaciers aren't melting. If anything, some are expanding.
Now, scientists have found an explanation for this mysterious glacial stability. While precipitation is increasing across the Himalayas, most of this moisture drops in the summer — except in Karakoram, where snow dominates the scene. "
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson

icefest

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Re: The Randolph Glacier Inventory, RGI
« Reply #2 on: October 25, 2014, 03:50:04 AM »
Interesting, this might mean that northern India and Pakistan need less water storage than one might have thought. At least until 2100 when warming will possibly overpower increased winter snowfall.

Open other end.