Click here to view article in its original context on Democrat and Chronicle online

RIT scientist heads team to measure polar ice melt

Written by James Goodman, Staff writer

Satellite imagery has helped scientists detect everything from wheat shortages in the former Soviet Union to deforestation in the Amazon.

Nowadays, satellites are using more sophisticated technology to determine how much polar ice has melted — a sign of global warming.

Rochester Institute of Technology associate professor John Kerekes is heading up a team that is creating a computer model that will guide scientists who are applying this technology in a future satellite launch.

The research is being funded with a $561,130 grant from the National Aeronautics and Space Administration.

Ice masses, which are often highly irregular in shape, can be measured by an orbiting satellite bombarding the mass with photons — bundles of energy that make up light — and then determining how long it takes for the photons to return to the satellite.

All this happens within a fraction of a second. When these bundles of energy hit an elevated section of ice, they will take a slightly shorter time to bounce back than if they rebound from a depressed ice area.

"If you send a pulse of light down to a flat surface, you know it is coming back — based on the speed of light — at a precise instant.

"But if that surface has hills and valleys and crevices, the photons are going to bounce around and it will take longer to come back," said Kerekes, 50, who is an associate professor at RIT's Chester F. Carlson Center for Imaging Science.

Measurements of the melting ice will be recorded when the satellite — traveling at a height of about 450 miles — passes over the Arctic region, which includes Greenland, and when it's over Antarctica, where large areas on the western side are melting.

Studying these changes over time provides a window into how much of an ice mass is melting.

Kerekes, who has a doctorate in electrical engineering from Purdue University, has a specialty in remote sensing — getting information from far away. He spent 15 years as a researcher at the Massachusetts Institute of Technology's Lincoln Lab before joining the RIT faculty in 2004.

University at Buffalo associate professor of geology Bea Csatho, who has an expertise in polar ice and holds a Ph.D. in geophysics, is also on the team.

The computer model that the RIT-Buffalo team is working on will be used by scientists examining the data from the NASA satellite Ice, Cloud and Land Elevation Satellite-2, which is expected to be launched in 2016.

Digital maps are expected to be produced from the team's computer model.

An important tool in developing the model is RIT's Digital Imaging and Remote Sensing Imaging Generation computer program, which Kerekes said is able to simulate how data will be generated and collected by the satellite.

Csatho heads up the NASA science team for the 2016 satellite and was part of the team for a NASA satellite that orbited between 2003 and 2009 that also used the technology — commonly called LIDAR (Light Detection and Ranging) — that bounces bundles of photons to measure the ice.

But the technology has been improved so that the sensors on the satellite can pick up many more rebounding photons that the satellite will transmit.

And scientists should have the advantage of the computer model that Kerekes' team is developing.

Csatho, 53, who grew up in Hungary, first came to the United States in the early 1990s on a Fulbright Scholarship.

She subsequently returned in the mid-1990s and spent more than a decade at the Byrd Polar Research Center at Ohio State University, before joining the UB faculty in 2006.

Ice sheets that make up much of Greenland, along with Arctic glaciers and ice caps, grew between 1500 and 1800, noted Csatho.

But she said that for the past 150 years there has been a gradual melting of this ice, with the pace sharply increasing during the last 15 years, both in the Arctic region and in parts of Antarctica.

"Glaciers are like conveyer belts moving ice. If they move faster, they will drain the interior of the ice sheets," said Csatho, who warns of the dangers of rising ocean levels and flooding.

JGOODMAN@DemocratandChronicle.com