Explorations
A Storm is Born
Dispatch 3: Using Bugs to Track the Storm
It's a Friday at the deserted municipal airport in Shamrock, Texas. I'm sitting in front of a computer in the cab of the SMART (Shared Mobile Atmospheric Research and Teaching) radar truck. The eight-foot-diameter radar dish, mounted on a pedestal attached to the truck's trailer, is pointed northwest, sampling a 140-degree swath. It sends pulses of energy into our sampling field that bounce back, or reflect, when they hit solid targets—everything from raindrops to airplanes.
SMART radar scans the field in eastern Texas.
On the monitor, I can see neat green lines where air streams form a triple point: hot dry air from the west joins warm, moister air from the south, and cooler air from the north. These lines are actually formed by great hosts of insects, buoyed by converging air streams and recorded by the radar as areas of high reflectivity. The bugs reveal the location and movement of the fronts.
The SMART radar sits at the southeast corner of an imaginary box formed with three other radar trucks. Field Coordinator Erik Rasmussen is guessing that the converging fronts will pass right through the approximately 150 square miles of territory we've staked out. By late afternoon, as the ground temperature rises and our anticipation grows, we're hoping to see some "CI," as the researchers call it. Convective initiation. Clouds billowing upward, lightning, precipitation. The works. "So far, we've racked up the no initiation cases," says Paul Markowski, assistant professor of meteorology at Penn State, who is traveling with the SMART radar team today. "It's time for a storm."
Collecting meaningful data will be a big challenge. We're trying to trap a moving target. Will the clouds burst in our box or two miles away? The whole armada may have to redeploy several times throughout the day, and while it's easy enough for the geek mobiles to change position, it's a little more difficult for the radars. It takes about half an hour for the SMART truck to set up and start scanning. Steel plates must be placed on the ground so that the trailer's extendable feet don't sink into mud. The dish must be raised. Scanning coordinates must be entered into the computer.
The SMART Radar was designed and built by Jerry Guynes, an electrical engineer from Texas A&M University. He bought the pedestal, once used to mount World-War-I guns, from a military surplus store. The mobile unit is incredibly sturdy; it survived Tropical Storm Gabrielle near Venice, Florida last September. However, Guynes has yet to construct a protective cover for the steel dish, making it vulnerable to the quarter-sized (and larger) hail that storms on the Great Plains can produce. So Guynes, who is here to operate SMART radar for the IHOP (International H20 Project) team, warns Markowski that he wants to be on the road heading to safety before the weather gets serious.