UMass Tornado Researchers Heading Back To Great Plains

The UMass team designs and constructs specialized radars, which are installed on customized pick-up trucks emblazoned with the University’s logo. The group chases tornadoes and monitors them using the truck-mounted radars and videocameras. 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.

Engineers and scientists then scrutinize the data collected, in an effort to pinpoint what meteorological conditions enable a supercell, or large rotating thunderstorm, to drop a funnel. 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.

This year, the team will introduce a long-range, three-centimeter wavelength radar, which can scan storms 80 miles away. The radar is similar to those used on ships, but has been customized to monitor extreme weather. The antenna resembles a white cone about the size of a picnic table, and is specially constructed to withstand severe weather. Inside the truck’s cab, a keyboard and joystick control the antenna scanning machinery, while a monitor provides researchers with real-time images of the storm’s location, motion, and structure. This information will help researchers detect developing storms, decide which storm to chase when there are multiple storms in the area, and approach tornadoes safely and efficiently even when the twisters are hidden in rain.

The new radar will be used in conjunction with the team’s close-range, three-millimeter wavelength radar, which is used to gather extremely detailed information within just a few miles of a storm. “The long-range radar is like using a camera, because you get a good overview of the storm activity in the area,” explained Pazmany, “while the short-range radar is like a microscope. It does not see very far away, but resolves very fine detail that you cannot get with any other existing radar.”

The team is hopeful that this year’s data from the two radars will provide the opportunity to test a new algorithm, said Pazmany. “The storms’ images, collected with the two radars at two different frequencies, can be processed with an artificial neural network to estimate quantitative properties of the storms, such as the distribution of liquid and the size of rain drops, in addition to the conventional Doppler (velocity) and reflectivity (structure) images. Essentially, we’re getting two different sets of information, which gives us a much more complete picture of tornadoes and their parent storms.”

UMass researchers say that the new long-range radar is a prototype. They are hoping to eventually establish a network of these portable radars to monitor extreme weather events.

Images and additional data are available at http://abyss.ecs.umass.edu/tornado