| Past president of the AMS Jonathan T. Malay presents a 2012 Special Award to New Mexico Tech professors (from left) Paul Krehbiel, Bill Rison and Ron Thomas.
| Bill Rison (left) and 2011 graduate Dan Rodeheffer with the latest generation of the LMA, the solar array.
| Bill Rison sets up a sensing station in Chile in 2008 during the eruption of Chaiten Volcano.
| Krehbiel (left) and Thomas set up a sensing station near Mt. Redoubt in Alaska in 2009.
|The interior of the award-winning Lightning Mapping Array.
The three professors began developing the array in the mid-1990s, thanks to a special research infrastructure grant from the National Science Foundation. The proprietary hardware and software system allows scientists and weather forecasters to image lightning inside storms.
“It was really nice to be recognized,” Rison said. “We put a lot of work in this and we think it’s made a difference in the community, getting this type of data out to researchers and operational people who can help with weather forecasts and lightning warnings.”
Krehbiel said the AMS gives out a number of named awards each year, and a few “Special Awards.” This year the Society presented two special awards.
“It’s pretty prestigious,” Krehbiel said. “Bill Rison has been the guru behind the system.”
Dr. Bill Winn, director of the Langmuir Laboratory, said the Lightning Mapping Array has a practical importance because the locations and time evolution of lightning channels inside thunderclouds cannot be photographed. The Array helps determine intensity and movement of thunderstorms and the hazards to airborne and ground-based activities.
“The cultural importance of the Lightning Mapping Array lies in its great contribution to understanding lighting,” Winn said.
For example, research based on Array data has shown that that a single lightning flash can travel horizontally tens of kilometers inside clouds. Further, scientists have discovered that lightning usually remains inside clouds when it begins above the main negative charge but it strikes the ground if it begins below the main region of negative charge, he said.
“In research programs to study lightning, the Lightning Mapping Array is indispensable because tells us much about how lightning behaves,” Winn said.
The LMA also provides a framework for understanding measurements made with instruments on the ground and carried aloft by airplanes, balloons, and rockets. “The three of us got the award, but it’s been a much bigger effort,” Rison said. “We’ve had a lot of talented students and scientists at Tech working on this. We wouldn’t have been able to do it without them.”
Tech Vice President of Research Dr. Van Romero said the award is well-deserved.
“This is an excellent example of the work that happens at Tech and, in particular, in the Langmuir research group,” Romero said. “They took something from theory to practice and now we’re making practical use of it. They look at the fundamentals of physics and, combined with electrical engineering, have created a device that protects us from lightning events.”
New Mexico Tech has a long legacy of lightning research since the 1950s. Langmuir Laboratory for Atmospheric Research, opened in 1963 atop the Magdalena Ridge overlooking Socorro, was the first lightning research facility in the United States. Tech physicists Charles Moore and Marx Brook were the first researchers to study volcanic lightning when they made electrical measurements around the Surtsey and Heimaey eruptions in Iceland in the 1960’s and 70’s.
The 15-year project has been funded by a series of grants from the National Science Foundation. Tech lightning researchers have made a number of scientific and technological breakthroughs over the years, but the Lightning Mapping Array is probably the most profound invention. The array allows scientists, meteorologists and storm chasers to pierce the veil of clouds to “see” lightning as it occurs.
“With each lightning flash, we are able to monitor how it moves through the clouds and where it goes,” Thomas said.
In addition to audible noise (thunder), lightning also produces impulsive radio waves, which travel at the speed of light – about one foot per nanosecond. A widespread array of stations uses GPS timing to measure arrival times with 40 nanosecond accuracy. The sensors are able to pinpoint the three-dimensional location of individual lightning sparks within about 40 feet, Krehbiel said.
Hundreds or thousands of individual segments of a single lightning flash can be mapped with the Lightning Mapping Array and analyzed on high-end computers to reveal how lightning initiates and spreads throughout a thunderstorm ... or within a volcanic plume.
“We receive radio bursts of noise generated from sparks of lightning, just like the static you hear on an AM radio during a thunderstorm,” Thomas said. “We use our sensing stations to locate the lightning and track its path.”
The sensing equipment has three proprietary systems developed at New Mexico Tech – the circuit boards, the firmware and the data analysis software, Rison said.
The first system weighed more than 200 pounds, had only 2 gigabytes of data storage and was housed in a large contractor’s workbox. The group had to retrieve data tapes from the sensors every two days.
“A significant breakthrough was designing sensors that were more compact,” Krehbiel said. “Just before the Mount Augustine eruption in 2006, we developed a portable station that could be easily and quickly transported to study Augustine’s explosions.”
The second generation system weighed about 10 pounds, had more than 160 gigabytes of storage capacity and fit into a picnic cooler. The improved data storage allowed the system to record data continuously for more than three months. The compact size allowed for rapid deployment.
Development of the portable sensing stations permitted Tech scientists to respond quickly to volcanic eruptions. In 2006, the Tech scientists deployed two stations at Mount St. Augustine in Alaska. In 2008, they deployed four stations at Mt. Redoubt, also in Alaska. In 2009, they deployed four stations at Chaiten Volcano in Chile and, in 2010, they deployed six stations around the Eyjafjallajokull eruption in Iceland.
The current, third generation incorporates solar cells and solid state hard drives, which permit lower power consumption and allow more rugged operation.
The stations now consume 10 watts of battery power and the hardware weighs about 10 pounds. Rison wants to reduce the weight to 3 pounds and reduce power consumption to 1 watt. He has several electrical engineering students working on that challenge.
Permanent installations of Lightning Mapping Arrays are now dotting the landscape. The first was set up around Langmuir Laboratory near Socorro. Other LMAs include the following:
- NASA Marshall Space Flight Center in Huntsville, Ala.
- The National Weather Service in Washington, D.C.
- The National Severe Storms Laboratory at the University of Oklahoma
- White Sands Missile Range in New Mexico
- Dugway Proving Grounds in Utah
- The Ebre Delta in Catalonia, Spain
- Texas Tech University in Lubbock
- Texas A&M will soon be installing an LMA network in the Houston area.
Two more LMAs are currently in the works. One will be owned by NASA and deployed by the Tech group in the south of France. The other is being set up in north-central Colorado for cooperative studies with Colorado State University and the National Center for Atmospheric Research.
“The Colorado LMA is going to be our best network yet,” Rison said.
– NMT –
By Thomas Guengerich/New Mexico Tech