Published: April 1, 2008

University of Colorado at Boulder Professor Xinzhao Chu has been awarded a $1.2 million grant from the National Science Foundation to build a revolutionary lidar that will allow scientists to probe the upper layers of the atmosphere with unprecedented accuracy.

Chu's MRI lidar will allow scientists to take simultaneous measurements of temperature, wind, clouds and particle pollution at altitudes of 18 to 75 miles above the Earth's surface. She is a professor of aerospace engineering sciences and a fellow of the Cooperative Institute for Research in Environmental Sciences, or CIRES.

"We know so little about the middle and upper atmosphere, and yet we think a lot is happening there that influences the climate we experience at the surface," Chu said. "This new lidar is going to push the technology envelope and open doors for many new climate studies."

Similar to radar, which sends out pulses of radiowaves, lidar is a remote-sensing device that sends out pulses of laser light. By comparing the original light wavelength, or frequency, to the received frequency, and by analyzing how much time it takes for light waves to transmit and return, scientists like Chu can detect very slight changes in atmospheric temperature and wind speeds, as well as measure concentrations of particles in the air.

Lidars are especially useful for detecting higher altitude atmospheric phenomena such as gravity waves and rare polar mesospheric clouds, the highest clouds in the atmosphere, which some scientists suspect are now more prevalent due to global climate change.

Chu's MRI lidar also will be designed for mobility. Once the remote-sensing tool is built, the lidar will travel to regions as distant as the Antarctic, the Arctic and the equator to gather information about how the upper atmosphere interacts with Earth's climate system.

Helping Chu develop the MRI lidar are CU-Boulder aerospace engineering sciences Professor Jeffrey Thayer, CIRES research scientist Wentao Huang, Arecibo Observatory senior research associate Jonathan Friedman, Colorado Research Associates' Bifford Williams and Triad Technology's Archie Brown.

The MRI lidar will be constructed on the CU-Boulder campus over the next two years. The grant is part of NSF's Major Research Instrumentation Program.

CIRES is a joint institute of CU-Boulder and the National Oceanic and Atmospheric Administration.