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Introducing Konrad SteffenBy Annette Varani On September 6, CIRES Director Susan Avery transferred her responsibilities to CU-Boulder Professor of Geography and CIRES Fellow Konrad Steffenfor the year she is on sabbatical in Washington, D.C.
Who is Konrad Steffen? In future annals of arctic science, Steffen may become one of the legends. A climatologist known as "Koni" by all at CIRES, Steffen has spent an average of seven weeks in the high Arctic every summer for the past 27 years-and is himself responsible for a large part of the instrumentation that lets the world know, hour by hour, conditions on the Greenland Ice Sheet and how they're changing. Steffen's career spans the dawn of satellite remote sensing, unthought of advances in scientific technology, and a period of profound change not only for the Greenland Ice Sheet but for global climate change. Without his work, together with that of his students and associates, our knowledge of arctic climate, warming, and melting dynamics would be much impoverished. Steffen has studied conditions in the Canadian Arctic, Switzerland, and China. But Greenland's ice sheet-"the weather machine of Europe" as Steffen calls it-has drawn him since 1990. That first visit, he stayed three months. "We probably have more information on nearby planets than we do of Greenland because of the amounts of money and focus spent on the space program," Steffen says. "Parts of Greenland have never been measured because the inclination of polar orbiting satellites obscures our view of the very northern parts. "In Greenland, mass balance of the ice is the key question," he says. Citing the difference in results yielded by two over-flights of Greenland by an airborne laser altimeter at a five-year interval, Steffen says that while the summit does not appear to be changing much, differences in the ice sheet over time are much more obvious at the perimeter. "We don't know how much ice is breaking off and going out." Steffen says. "Until we know the velocity of all the Greenland glaciers we can't calculate how much ice is going through the gate." Filling in the data gaps is one "part of the challenge" to which Steffen is particularly well-suited, given early training in engineering that has proved in combination with climatology to literally be instrumental to success in the field. "In the early days of the 1970s we had no data logger," he recalls. So Steffen improvised a device that recorded data on magnetic tape that could be read by computers. Since then, development of instruments suited for life at minus 40 degrees Celsius has been all in a day's work, whether it means devising sensors fitted for spectral reflectance measurements or for remote climate recording. In recent decades "technical development has been enormous" Steffen says. Since establishing the first automatic weather station in 1990 with funding from NASA and the National Science Foundation at a location known as the "Swiss Camp," Steffen and his crews have installed a minimum of two new stations per year. Today, Steffen maintains more than 20 sites in a system known as the Greenland Climate Network. Climate conditions measured by the weather station network are beamed from the Ice Sheet via satellite on an hourly basis. The system is augmented by another six "smart stakes" equipped to log data that are collected annually by researchers in the field. For ten years, Steffen's computers in Boulder have been receiving several hundred megabytes of data per day from ground penetrating radar and other instruments. These data provided the time-series helpful in confirming that ice sheet flow accelerates with surface melting, surprising research results reported in the June 6, 2002 issue of Science Magazine in an article Steffen co-authored (Zwally et al. Science 297: 218-222). "It was known for a long time that glaciers sped along lubricated at the base by meltwater," Steffen says. "But it was not thought to be true of ice sheets." By publication date however, Steffen was once again in Greenland conducting fieldwork on the Petermann Glacier with colleagues from the British Antarctic Survey and the Jet Propulsion Laboratory. "The Petermann Glacier is a big floating tongue that extends 60 kilometers over the ocean," he explains. "From aircraft measurements using an ice-penetrating instrument with a laser altimeter, we can measure the glacier's thickness and note changes. "At the grounding line the glacier is melting rapidly-20 meters per year," says Steffen. The grounding line is the juncture where the glacier leaves the ground and extends over the ocean. The 2002 study, to continue over two field seasons, is designed to examine bottom and surface melting in the proximity of the grounding zone and determine whether the Petermann Glacier is becoming thinner and less stable. Steffen supervises five ongoing Greenland field projects funded equally by NASA and NSF that include an ice velocity study, the Petermann Glacier project, an examination of turbulent atmosphere at Greenland's summit, an aerosol and climate cloud-monitoring project, and a collaboration intended to refine the melt detection accuracy for the Ice sheet. Concurrently, Steffen supervises one master's degree student, five doctoral students, and two postdoctoral students while also teaching graduate-level classes. How will a scientist and educator who authored or co-authored 10 published papers in peer-reviewed journals in addition to his normal responsibilities, as Steffen did in 2001, also find the time to temporarily direct a 550-person science institute? "You have to like it," he laughs. |
