While the U.S. Department of Energy conducts high-profile weather studies in Salt Lake City, another federal agency is quietly piggybacking on the study, gathering meteorological data for its own purposes — information that could be used to defend against terrorism during the 2002 Winter Olympics.

The other agency, not mentioned in official announcements of the DOE study, is the Defense Threat Reduction Agency, based in Alexandria, Va. It is part of the U.S. Department of Defense.

Lt. Col. Andy Walker of the Defense Threat Reduction Agency told the Deseret News that his agency is part of the DOE study but that its role in the overall effort is minor. However, a DOE official denies that the Defense Threat Reduction Agency is part of the study.

"We're just measuring some of the equipment," Walker said.

The main study, sponsored by the DOE, is called the Vertical Transport and Mixing Experiment. At least 60 scientists are checking weather patterns above Salt Lake City throughout October.

The VTMX study includes release of a harmless tracer chemical to measure air motion through Salt Lake City. According to the Defense Threat Reduction Agency, that chemical is sulfur hexafluoride.

But the tracers may have another application besides predicting weather patterns. They also might be used to check equipment that is designed to sniff out deadly chemicals, such as the sarin gas that killed 12 and injured thousands during a 1995 attack in a Japanese subway.

If terrorists were to attack the Winter Games by releasing deadly chemicals, detecting those chemicals in downtown buildings could be vital to saving lives.

Announcements of the VTMX study said lasers, aircraft and meteorological balloons are gathering information to improve weather forecasting, with a focus on pollution that is trapped in urban areas during smoggy inversions. Officials did not mention any involvement of anti-terrorism agencies.

But both DOE and the Defense Threat Reduction Agency indicate the defense group has been piggybacking onto the overall experiment to see whether its equipment can detect the tracer chemical inside buildings.

"The only thing I know is, there are people like DTRA who are trying to prepare for the Olympics," said Joe Shinn of the DOE's Lawrence Livermore National Laboratory in Livermore, Calif. Shinn, contacted in Salt Lake City, is one of the directors of the VTMX study.

"I think that they are interested in using releases that we make to see if material penetrates into buildings." The buildings are in Salt Lake City, but he refused to say which ones were involved in the tests.

"They're interested in what we're releasing to see if they can detect (it) in buildings."

The Defense Threat Reduction Agency says the information it gleans can be used by various groups in defending "large events," such as the Olympics. It provided similar data to authorities during NATO's recent 50th anniversary celebration in Washington, D.C., in case terrorists tried to attack the celebration.

However, Capt. Bob Bennett of the Defense Threat Reduction Agency denied that this study has any specific tie to the upcoming Winter Games. "No sir, we are simply taking advantage of the opportunity that DOE is doing an atmospheric experiment in an urban area to confirm our models," he said.

A base as distant as Dugway Proving Ground in Utah's western desert is involved in the VTMX study, Dugway spokeswoman Melanie Moore said.

In response to the Deseret News' query, the Defense Threat Reduction Agency said the organization was involved in the VTMX study but gave few details about its role.

"The objective of the experiment . . . is to gain a better understanding of atmospheric conditions affecting air quality in mountainous areas," a written response by DTRA says.

"DTRA is funding measurements of wind, temperature and atmospheric turbulence in the downtown area to document atmospheric conditions during the tracer releases. The tracer and meteorological data collected during the test will contribute to the development of improved dispersion models for urban air quality."