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" &amp;quot;The polar ice sheets are undergoing rapid changes. Everybody knows that. What we don&amp;#039;t know is why,&amp;quot; says professor Sivaprasad Gogineni, director of the Center for the Remote Sensing of Ice Sheets, or CReSIS. To find out, glaciologists usually travel to the most inhospitable corners of the world to gather data during small seasonal windows of opportunity. But now CReSIS engineers, based at the University of Kansas, are combining digital radar equipment with unmanned aircraft for the first time to give scientists a much-needed edge.  Why are glaciers melting? Global warming is only part of the reason. Some scientists blame a thin layer of water that can form between a glacier and its bed. Whether it comes from melting surface water or geothermal heat, they say this layer acts like a lubricant, speeding the flow of glacial ice into the seas. But studying a wafer-thin blanket of water under a 3000-meter-thick glacier ain&amp;#039;t easy, unless you take to the air--and the airwaves. Gogineni and his team of engineers have developed more effective digital radar sensors, which detect water layers by bouncing radio waves off the glacial bed. The sensors have eight antennae for eight independent data streams from each echo--a vast improvement over single-channel sensors. They&amp;#039;re being used by partner glaciologists from Kansas, Ohio State and other universities. After testing the new radar on the ground in Greenland, CReSIS aerospace engineers are now building a $1.2 million unmanned aerial vehicle, or UAV, to carry the smaller, lighter, lower-power radar. The UAV, which use differential GPS for a 10 centimeter position accuracy, will replace manned flights in a hulking, four-prop P3 Orion World War II subhunting plane. &amp;quot;The P3 is expensive. It burns lots of gas. And it puts people&amp;#039;s lives at peril every time one goes out,&amp;quot; says University of Kansas electrical engineer and CReSIS team member Chris Allen, who has flown on the 8-hour data-collection trips. &amp;quot;That limits research.&amp;quot; CReSIS hopes to deploy its glacier-sensing UAV next summer over Greenland. The sophisticated system will be capable of gathering one terabyte of data per 8-hour flight, which creates a whole new set of challenges--how to archive and manage such vast amounts of data in the field, when the field is a polar ice sheet. The solution? Partners from the University of Indiana are developing the Polar Grid, a portable cluster of 32 processors that can handle data onsite overnight, even in subzero conditions.  Gogineni hopes to incorporate the data gathered into a large-scale ice sheet model and then couple that with a global climate model to do a much better job of predicting things like rising sea level. That might lead to mitigation, he says, in &amp;quot;building dikes like the Netherlands is doing, or moving people. Since this involves extreme cost and a lot of humans, it&amp;#039;s an important topic.&amp;quot; TECH WATCH: Studying a Mystery of Global Warming, NASA Will Fly on Space&amp;#039;s Edge ANTARCTIC BLOG: Measuring Ice from Inside the Earth With PM&amp;#039;s Climate Scientist PODCAST: Global Warming Experts Discuss Future of the Climate Frontier "^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.popularmechanics.com/science/environment/a2358/4236038/>