UMass to lead weather radar system project
$40 million effort could revolutionize forecasting of tornadoes, hurricanes
The University of Massachusetts at Amherst will lead a $40 million effort to build a revolutionary new radar system that could improve the way the nation predicts tornadoes, hurricanes, violent thunderstorms, and other kinds of severe weather, scientists said yesterday.
The team plans to build an armada of small, inexpensive radar dishes that will allow forecasters to track weather in much more detail than now possible -- and closer to the ground, where today's technology has dangerous blind spots."For the first time, this will allow us to map the most crucial part of the atmosphere, where the wind drags on the land," said David McLaughlin, an associate professor at UMass-Amherst who will direct the work. "That will allow us to see individual tornadoes and chase them down individual streets."
The project represents a major shift in the science of weather detection and prediction, which currently depends on large, two- or three-story radar installations that stand like sentinels hundreds of miles apart. Instead, atmospheric scientists hope to use recent advances in communications and computers to build a weather-watching system more like a guerrilla army: dispersed, flexible, and potent.
"This is a really neat approach," said David J. Carlson, director of the atmospheric technology division at the National Center for Atmospheric Research in Boulder, Colo.
Called the Center for Collaborative Adaptive Sensing of the Atmosphere, the UMass project represents a major boost for a university that has struggled recently with state funding cutbacks. Anchored by a $17 million grant from the National Science Foundation, the center will also be funded by a consortium including the Commonwealth of Massachusetts, which provided $5 million; other universities; and companies including Raytheon.
If successful, the new technology could also be used to track the low-level winds that could carry a biological, chemical, or radiological attack. It could also help close a large gap between the developed countries and the Third World, where many people die in weather-driven disasters because it is too expensive to build multimillion dollar radar facilities.
The team has already built prototypes of the small radars that would make up the system at a cost of about $40,000 each, and hopes to be able to build them for $20,000, far less than the multimillion dollar pricetag of a current weather radar installation. The goal of the five-year project is to improve the effectiveness of small weather radars and also design a computer network that will allow a large number of radars to communicate with each other and generate a clear picture of what is happening.
Radar has brought tremendous advantages to meteorologists, but also has a fundamental limitation: The further away an object is, the higher and larger it must be to be visible. Today's powerful radar can generate beautiful images of a vast storm front crawling out from the Rockies, but completely miss a thin, twisting tornado dropping from the sky and tearing up the ground between the radar outposts.
"There is a whole variety of fine-scale severe weather that is missed," Carlson said.
The team plans to develop a small radar that could be spaced every 20 miles or so, McLaughlin said. Unlike today's weather radar installations, which have one beam like a flashlight, these will have 10 beams, each of which can be moved independently. The radar will also operate at a higher wavelength, which doesn't travel as far, but gives better resolution.
This fine network would leave bad weather nowhere to hide, McLaughlin said. His team at Umass-Amherst is a leader in making inexpensive weather radars, but the idea will only be practical on a broader scale if the radars can be made cheap, sophisticated, and reliable enough that they don't need expensive maintenance, said Frederic Fabry, a weather radar specialist and assistant professor at McGill University.
Another difficult task will be to design the software that allows all of the radars to communicate. For example, several radars might all get a different image of a part of a storm, from different angles. The software needs to decide what the storm really looks like.
The first test of the system will come in 2005, in Oklahoma's "Tornado Alley." Next, the team will move to Houston, which is hit with severe flash floods. Despite all the technology in place today, weather forecasters still can't say how much rain is hitting the ground, because rain evaporates on the way down and the big radar loses track of it once it gets close to the earth. The team will see if it can do better using the new system, which will also be tested in Puerto Rico.
Gareth Cook can be reached at firstname.lastname@example.org
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