Home >> Global Outlook for Ice and Snow >> Antarctica, showing rates of surface-elevation change derived from satellite radar-altim ...
File type Download Size Language
.png .png Download 192 kb -
.pdf .pdf Download 1 mb -
Uploaded on Tuesday 21 Feb 2012 by GRID-Arendal

Antarctica, showing rates of surface-elevation change derived from satellite radar-altimeter measurements

Year: 2007 Author: Hugo Ahlenius, UNEP/GRID-Arendal
The figure shows rates at which the ice-sheet mass was estimated to be changing based on radar-altimeter data (black), mass-budget calculations (red), and satellite gravity measurements (blue). Rectangles depict the time periods of observations (horizontal) and the upper and lower estimates of mass balance (vertical). Measurements by satellite techniques based on gravity indicate mass loss at a rate of 138 ± 73 billion tonnes per year during 2002–2005, mostly from the West Antarctica Ice Sheet. That is equivalent to a rise in global sea level of 0.4 ± 0.2 mm per year, or 10–30% of the global rate measured since the 1950s, and is in good agreement with recent massbudget estimates. However, two interpretations of satellite radar altimetry pointed to a much smaller loss of about 31 billion tonnes of ice per year or a net gain of about 27 billion tonnes per year. The difference between these estimates from totally independent techniques reflects the uncertainties in these difficult measurements; nevertheless, on balance, they indicate a recent shift to a net loss of Antarctic ice and suggest that losses may be accelerating. Similar conclusions result from studies of Antarctic Peninsula glaciers, indicating that they are melting much faster than previously predicted and are probably already contributing significantly to sea-level rise.
Views: 517     Downloads: 206     Rating: 4
Major glacier hazard locations
Mean snow-cover extent in the Northern Hemisphere 1966-2006
Projected winter temperature changes in the Arctic
Glacier changes on Nevado de Santa Isabel, Colombia
Sea ice concentration change over the 21st century as projected by climate models
Projected reduction in snow 2080-2100
Ice sheets, schematic illustration for Greenland and Antarctica
Ice avalanches of the Nevados Huascarán in Peru