Four middle and upper atmosphere lidar groups collaborate to unify the scientific and technological applications of resonant lidar systems now at the University of Illinois, the Alomar Observatory in Norway, and at Colorado State University. The consortium structure coordinates simultaneous performance of the lidar systems and the sharing of existing data, coordinates data taking strategic planning within the upper atmospheric lidar community, facilitates more rapid dissemination of technical lidar advances, and coordinates education, training, and outreach activities. The consortium establishes a Technology Center that focuses on unified establishment of robust and stable lidar operation, the exploration of advanced laser and optical technologies, and the expedition of technology transfer within traditionally isolated and competing lidar groups. The initial goal of the consortium is to make regular nighttime and daytime measurements of temperatures and winds in the upper mesosphere and lower thermosphere commonplace and consistent at the three primary lidar sites.
The main research activities have been to install, upgrade, and operate the Na wind/temperature lidar system at Cerro Pachon, Chile. The lidar is operated and managed by the University of Illinois, Remote Sensing and Space Science Laboratory and the Embry Riddle Aeronautical University. The measurements have included temperature and winds in the 80-110 km altitude region at the 30o south latitude in the Andes. A new facility was funded by the University of Illinois Electrical and Computer Engineering Department, and fabricated with the support of the Association of University Research in Astronomy (AURA). The facility was completed in August, 2009, and the lidar was installed in September, 2009 along with correlative instrumentation including a Meteor Radar, an OH Imager, and an airglow Photometer (U of Illinois), a temperature mapper (Utah State University), and an Infrared OH Imager (The Aerospace Corporation). The lidar system requires onsite operation, whereas the correlative instrumentation is operated with remote operation through the internet access. An image of the lidar beam is shown propagating vertically from the Andes Lidar Observatory (ALO) in Figure 1. The major findings have included the investigation of atmospheric conditions that are conducive to preconditioning the atmosphere to instabilities with the coupling of gravity waves and tidal waves. The measurements of winds with altitude and wind shears force conditions of shear instability and overturning, similar to that observed in ocean waves nearing a shallow shore. Convective instabilities are also observed, where instabilities occur as the temperature lapse rate approaches 9.5 degrees/km. The instabilities are forced by various conditions including wave-wave and wave-tide coupling. Studies are under way, comparing the data from the Cerro Pachon site to previous measurements made at Albuquerque, NM and Maui, Hawaii. Figure 2 describes a sequence of time histories for Na density, temperature, and winds measured on August 14, 2010. The data from the observations have supported training for 3 undergraduate engineering students, 2 Masters degree students, and 4 Phd students. The research at Cerro Pachon on the Na wind temperature climatology is being communicated to the astronomer community at this same site for the use of understanding the environment for guide star environments used on the astronomical Gemini telescope, and the future LSST facility.
