Featured Science Paper
Isochronous information in a Greenland ice sheet radio-echo sounding data set
Glaciers draining ice from Greenland and West Antarctica have shown recent accelerations. This leads to rapid draw-down across regions of these large ice sheets. Over the longer term these ice-sheet draw-downs will lead to substantial rises in global sea level. To accurately predict these future changes it is necessary to correctly model ice-sheet flow. Thus the evaluation of ice-sheet models is one of the pressing problems in the study of climate change.
One good source of data for testing the ice-sheet models is from aircraft based ice-sheet surveys. The Center for Remote Sensing of Ice Sheets (CReSIS) Greenland airborne radio-echo soundings project has been aerially surveying Greenland over the past 20 years. The resultant radio-echo sounding data set is complex in that it has been acquired using an extensive, and continuously evolving, set of aircraft and radar systems. The data set of more than 200 gigabytes covers over 500,000km of flight path.
This paper examines the question of how much information is contained within the large complex CReSIS data set. Here, we use new efficient automatic algorithms run on the British Antarctic Survey supercomputer to identify regions containing good ice-age data. We show that good data is present within 36% of the data set, between 1,000 and 3,000m in depth this rises to more than 50%. However we show that in regions where cold ice from 20,000 years ago is present there are few good ice-age data available. Ice structure data sets, based on the method pioneered here, will help enable the evaluation Greenland ice-sheet models.
Louise C. Sime, Nanna B. Karlsson, John D. Paden, and S. Prasad Gogineni
Geophysical Research Letters, doi:10.1002/2013GL057928, 2014