Researchers planning long-term upper atmosphere study


Bridget Maiellaro, ECE Illinois

The Huancayo Observatory in Peru
The Huancayo Observatory in Peru

In January, ECE Professors Gary R Swenson, Steven J Franke, and Chester S Gardner traveled to Peru to investigate an observatory site that is a candidate for future operation of upper atmosphere instruments. The information-gathering trip will help with site selection for a long-term study in 2008.

On the trip, which took place from Jan. 10 to Jan. 12, the professors researched the Huancayo Geophysical Observatory, located approximately 200 kilometers east of Lima and Jicamarca. While there, they determined whether the site would adequately serve their future research needs.

A major interest of the group is to study the part of the atmosphere that couples into the ionosphere. The group discovered that the observatory, operated by the Geophysical Institute of Peru, a Public Agency Decentralized of the Sector Education, has the size and high altitude to be able to accomplish such a field measurement, Swenson said.

“The upper-atmosphere dynamics are known to couple to the lower atmosphere to affect compositions, which can affect climate and ozone,” Swenson said. “The big picture is to understand our atmospheric dynamic processes.”

Over spring break, the group will travel to a large astronomy facility located in Chile. After that site visit, they will determine where to conduct the long-term study, lasting anywhere from five to ten years. Swenson said that the study will involve measurements from several radar and optical remote sensing systems.

“The goal is that, by a year from now, January of 2008, we will be operating out of either Peru, Chile, or a site in Hawaii,” Swenson said.

The long-term study will involve taking data from the different seasons of the year due to significant differences in the wind fields, during which the group will operate in “campaigns.”

“Our students and staff will go to the facility and operate for three weeks, likely three to four times a year,” Swenson said. “After the instrumentation is installed and established, we will work with the local observatory personnel to operate the systems.”

Currently, much of the group’s focus is on instabilities in the atmosphere and the effects of small-scale waves. In order to do that, they use Laser Imaging Detection and Ranging, commonly known as LIDAR. LIDAR is similar to radar but uses a pulsed laser light instead of radio waves.

Other research tools used in researching the chemistry of the atmosphere include imagers, spectrometers, and meteor radars. On the trip to Peru, Franke accounted for the meteor radar interests, while Swenson and Gardner represented the sodium wind/temperature LIDAR and imagers.

“The basic premise of understanding these small-scale waves and their impact on the dynamics in the atmosphere is a fundamental problem that remains in atmosphere dynamics,” Swenson said. “Our instrumentation and methods are unique in being able to investigate these processes in the upper atmosphere.”

Swenson feels that the group will return to Huancayo to conduct the long-term study because the location provides them with many essentials. Observing conditions and the science return are top priorities for the team, while getting to the site, support, and costs are all issues that they will consider carefully, he said.

“We also are very interested in being at high altitude, at least 10,000 feet,” Swenson said. “The sight we’re looking at in Peru is actually 11,000 feet.”

The series of trips and the final study are funded by the National Science Foundation and the Air Force Office of Scientific Research.