Research
Highlights...
 
 

ORNL's Dale applies math to the environment. See below.

Scientists are gaining new insights into the electrodynamic processes surrounding lightning by examining measurements of more than two million individual lightning strokes recorded by a sophisticated radio receiver aboard the FORTE satellite.

FORTE—which stands for Fast On-orbit Recording of Transient Events—was developed jointly by DOE's Los Alamos and Sandia national laboratories.
 

Los Alamos and Sandia teamed up to develop the FORTE satellite.

The lightning measurements recorded by FORTE are sufficiently detailed that the researchers can pick out signals from the separate processes that build to form an atmospheric discharge, providing a new, high-quality tool for deepening understanding of the physical processes governing lightning.

The researchers also are linking FORTE recordings with ground-based measurements from the National Lightning Detection Network and from a network of sensors that measure low-frequency electromagnetic emissions, or "sferics," and changes in the direction of the electric field.

Matching FORTE's readings with others could identify those radio signatures useful for remotely identifying important storm systems, convective cells that spawn tornadoes, for example, or unleash damaging hail.

Launched in August 1997, FORTE began acquiring radio data almost immediately, and kicked into high gear when it unfolded a 30-foot-long antenna that had been stowed in a foot-high canister for launch. The sophisticated radio receiver samples a wide range of radio frequencies at a very high rate, essential since the impulsive radio emissions associated with lightning last less than a thousandth of a second. The receiver can make a recording and reset its trigger almost instantaneously.

FORTE was developed to demonstrate advanced technologies for detecting nuclear weapon detonations and thus help curb nuclear proliferation.
"Lightning is of interest to Los Alamos' national security missions because there is a parallel between the spectrum of lightning emissions and the electromagnetic pulse created by a nuclear weapon detonation," said Los Alamos physicist Abe Jacobson, who heads the FORTE science team.

Submitted by DOE's Los Alamos National Laboratory
 
 
 

A college class in ecology taken to fulfill a requirement as an undergraduate mathematics student started Virginia Dale on a trail she's pursued from coast to coast and around the world for two decades.
 

While ecology examines the relationships between plants, animals and their environments, mathematics enables Dale to express those relationships using equations. And just as there's beauty in nature, there's a certain beauty in mathematics, which Dale uses to solve complex environmental problems.

"For example, we work a lot with trees," said Dale, a senior scientist at DOE's Oak Ridge National Laboratory. "We study effects of natural and manmade disturbances to forests. Since trees live hundreds of years, we have to rely on mathematics and computer simulation models to predict impacts over decades and centuries."

Information gained through computer simulations can help policy makers in their decisions involving land, and land management is what Dale's work is all about. Preserving habitats often requires nothing more than a little thought and planning. For example, computer models of endangered woodpeckers and butterflies show the importance of animal movements, so management efforts to create or maintain paths can help them thrive. These efforts may be as simple as lifting the cutting blade of lawnmowers when they mow areas containing the plants the butterflies eat. 

Dale's laboratory is more often than not federal government land obtained decades ago as buffer for the development of nuclear weapons technology or for military reservations.

"Protected from commercial disturbance and fragmentation over the ensuing five decades, the two million acres of the DOE research parks have evolved into ecological sanctuaries of remarkable size and diversity," Dale said. 
In recent years, however, there's been a push to sell this land for residential or industrial development, and Dale is worried that valuable environmental resources and research possibilities will be lost. It's a real problem that will require a long-term ecological perspective and the kind of information that only mathematical ecology can provide. 

Submitted by DOE's Oak Ridge National Laboratory