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Engineer, Equipment Taking Campus by Storm
By Janice Palmer
Emmanouil Anagnostou wants to become what he calls a "now-caster", and it is his work to that end that has earned him one of the National Science Foundation's 2002 Early Career Development (CAREER) awards. As a hydrology and natural hazards expert, Anagnostou loves to study the kinds of weather most people love to hate - floods, lightning, and hurricanes, to mention just a few.
Instead of forecasts based on predictions of what is expected to happen, he is developing new methods and tools for precise precipitation measurements as they are occurring in real time, thus creating a "nowcast." For Anagnostou, an assistant professor of engineering, it is a matter of saving lives and property.
"People like to live near coastlines and rivers, and that has inherent risks. That's what struck me," says Anagnostou, a native of Greece. So, instead of becoming a civil engineer, as he had first planned, he turned his attention to natural hazards. He earned his bachelor's degree in hydrology and water resources at the National Technical University of Athens and earned a master's degree and doctorate in hydrometeorology at the University of Iowa.
"To design or construct anything, we need first to account for nature and its effects on our designs," he explains. "I decided I wanted to study the implications of severe weather and precipitation, and make that information available to engineers of man-made structures."
One of his tools will make an appearance this month on Horsebarn Hill, as part of his $423,000 CAREER award. The X-band Polarimetric On Wheels (XPOW) system is a specialized radar unit mounted on the back of a flatbed pickup truck. As a mobile unit, it can be deployed to locations where it collects a variety of data, including rain velocity and drop size, as severe weather systems pass over.
Recently, the unit was stationed in the Florida Keyes as part of Anagnostou's three-year NASA-funded project to improve hurricane landfall predictions. Although no hurricane is forecasted for Storrs, the XPOW will provide hands-on experience for Anagnostou's students studying applications in flood prediction for the Mansfield reservoir river basin.
This summer, his CAREER research will move to western Oklahoma and then to NASA's Wallops Island facility in Virginia, where the technology will be used jointly with other research instruments to improve methods for real-time rainfall estimations.
Anagnostou's relationship with NASA began in 1997, when he became a visiting scientist at the agency's Laboratory for Atmospheres at the Goddard Space Flight Center in Maryland. Soon after, he became a member of the science team for the Tropical Rainfall Measuring Mission (TRMM), which launched the first satellite equipped with radar dedicated to measuring precipitation around the globe. The mission's primary goal was - and still is today - to observe tropical rainfall and determine how it affects the global climate.
In 1999, Anagnostou accepted an offer from UConn's School of Engineering and brought along his research. He was developing a system for using the TRMM satellite radar to test and calibrate ground-based weather radar systems within its path. Those radars are used by weather service agencies to measure rainfall and issue flood warnings.
"This is extremely important, because radar is an electronic system and electronics can be fickle; yet to quantitatively detect precipitation, the equipment needs to be well-calibrated," says Anagnostou. "With over 400 radar sites around the globe and under the TRMM umbrella, keeping them properly calibrated would not be feasible, due to the cost and labor intensity. So we developed an approach for monitoring the calibration of hundreds of those radars using a single platform."
His research has shown variations among the radar sites do exist. An investigation of the sites in the southern United States, where flash floods are common, determined that rainfall is typically underestimated. By finding fluctuations like this, Anagnostou says real-time flood forecasting can be vastly improved.
It is advanced technology the National Weather Service is taking seriously. Negotiations are underway to give the agency use of the system.
But the majority of the globe is not covered by ground radar, so precipitation in those areas is not monitored. Take the oceans, for example; they cover nearly 70 percent of the Earth, yet there are virtually no ground
sensors measuring rainfall over the oceans. The more that is known about where it rains and how much, the more long-range climatic forecasts can be improved.
With funding through NASA, Anagnostou is developing a system to estimate global rainfall. As part of that, he has developed a long-range lightning detection system, because typcially, where there is lightning there is also rain. The system, called Zeus, advances precipitation estimates from NASA's meteorology satellites. This project brought him accolades from NASA, in the form of the agency's 1999 New Investigator Award.
Working with private industry, Anagnostou developed radio sensors and positioned them at five locations, from Puerto Rico to Florida, Alabama, Virginia and Rhode Island. The receivers detected lightning from the middle of the Atlantic Ocean to the West Coast and as far south as the Amazon Basin.
The system, according to Anagnostou, is valuable in several ways. Not only is it relatively inexpensive, but by combining lightning detection with satellite-inferred information, rainfall estimates for large areas are improved. It is more accurate than satellite information alone. Zeus improves flash flood predictions and climate forecasting in lieu of weather radar data, and by pinpointing the dangerous parts of a cloud, aircraft can easily avoid the lightning and turbulence.
The second generation of this system consists of six sensors located in Europe. Anagnostou says he is amazed that with just four working sensors from the network, they measured and plotted lightning strikes as far away as the U.S. East Coast and as far south as the African rainforest. This research netted him the 2002 European Geophysical Society's Plinius Medal.
Anagnostou is ready to take the next step - to make Zeus global. He estimates it would take about 50 receivers to cover the entire world. Now it is just a matter of finding the funding. Considering that his current work has brought in more than $2 million in research funds and several major awards, he may not have to wait too long.