US: After several attempts of a UCLA (University of California at Los Angeles) graduate student to quantify the amount of water draining from Greenland's melting ice sheet failed to present conclusive results, the student finally turned to Landsat imagery for the purpose. The new approach relies exclusively on the measurements of a river's width over time, which can be obtained from freely available satellite imagery.
Colin Gleason, lead author of the study and a doctoral student in geography in UCLA's College of Letters and Science, said, “As long as we can get multiple pictures of a river and apply this method to them, we can tell you how much water was flowing in the river at the time the images were taken.”
Laurence C Smith, co-author of the study and chair of UCLA's geography department, tapped Gleason for field work on the ice sheet because Gleason had a track record of developing innovative remote-sensing applications. In 2012, for instance, he created an algorithm for calculating the number of tree crowns in a forest using aerial laser-scanning technology.
The discovery was highlighted on 17 March in the online edition of Proceedings of the National Academy of Sciences (PNAS). Since submitting the article for publication, Gleason and Smith have tested the method on an additional 19 rivers worldwide.