Andrew Pazmany, the University of Massachusetts researcher and tornado chaser, will be on the trail of the swirling storms in tornado alley again this year now that tornado season has begun. Pazmany, along with colleagues at the University of Oklahoma, tracked last year's "monster" tornado on May 3, resulting in the highest resolution radar image ever recorded from a tornado.
Pazmany, also a UMass alumnus, designed and constructed the specialized radar, which is installed in a customized pick-up truck emblazoned with the UMass logo. He chases tornadoes and monitors them using the truck-mounted radar and a videocamera. A research faculty member with the University's highly-regarded Microwave Remote Sensing Laboratory, Pazmany's work is funded by the National Science Foundation.
Researchers are trying to determine what meteorological conditions enable a supercell, a large rotating thunderstorm, to drop a funnel -- particularly a dangerous tornado, which is classified as F4 or F5. By determining what conditions must exist for the formation of an especially fierce tornado, researchers hope to develop accurate predictions of when and where such a tornado may touch down, giving people time to evacuate. Pazmany notes that "some large, organized, rotating supercells, never drop a tornado -- while some ragged-looking, weakly rotating storms sometimes produce a monster, and no one knows why."
A new addition to the radar truck planned for this year is a modified marine radar, with a seven-foot-long antenna which rotates atop the radar truck like a helicopter blade. This new radar will help researchers determine the distance and structure of storms in the distance -- determinations that can be difficult to make by dead reckoning, particularly in rainfall, or during the nighttime. "Everything is swirling around and it's hard to judge the distance and motion of the storm," he said.
The team literally chases the tornadic storms, which are visible on the horizon up to 100 miles away. The radar truck is followed by a passenger car, with the vehicles maintaining radio contact. "We look at the maps and the data and sometimes choose between storms. It may take hours to reach a supercell even when it seems to be right in front of us," said Pazmany. "We drive under the cloud-base. If you're within two miles of a medium-size tornado, it feels very, very close, like you could reach out and touch it. You never want to be closer than a mile." The team logged 13,000 miles this way, last year. Pazmany videotapes the tornadoes while scanning the narrow-beam radar across them. The radar signals bounce off raindrops and flying debris, enabling scientists to track the movement of parcels of wind -- some of it blowing more than 300 miles an hour.
Note: Andrew Pazmany can be reached at 413-545-3495 in Massachusetts, 405-325-9832 in Oklahoma, or pazmany@alex.ecs.umass.edu. Images and additional data are available at http://abyss.ecs.umass.edu/tornado.