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.
(CRRL), ATM 0545353, was a six-year project with the University of Colorado (CU) as the lead institute directing the project and the Consortium Technology Center (CTC). The Consortium includes lidar observatories at the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR) in Norway, led by Northwest Research Assoc./Colorado Research Assoc. division (NWRA/CoRA), the Andes Lidar Observatory (ALO) in Cerro Pachón, Chile, led by the University of Illinois at Urbana-Champaign (UIUC), and the Utah State University (USU) lidar observatory in Logan, Utah. Other institutes affiliated with the Lidar Consortium are Embry Riddle Aeronautical University, Colorado State University, and Norwegian collaborators. The Consortium Lidar observatories use the sodium resonance wind and temperature (Na W/T) lidar technique, to provide fundamental measurements of the upper atmosphere region from 30-110km altitude at temporal and spatial resolutions that are difficult to achieve by other means. As a result, Na W/T lidars have yielded fundamental advances in our understanding of upper atmosphere dynamics, thermal structure, chemistry, and microphysics that were previously impossible. Part of the measuring domain where the Na W/T lidar systems are particularly capable is the mesosphere and lower thermosphere, known to be the coldest region in the entire Earth’s atmosphere with minimum temperatures occurring paradoxically in the summer months. This unique condition is a result of wave energy deposition in the upper atmosphere. The lidar measurements of simultaneous, height-resolved, wind and temperatures through the mesosphere and lower thermosphere enable significant advancements in understanding dominant wave momentum and energy transfer processes in the upper atmosphere. The mesosphere and lower thermosphere of the atmosphere also defines the reentry region of natural and man-made objects. The existence of a sodium layer, exploited by this lidar technique, is due to meteor ablation and complex atmospheric chemical pathways that lead to a well-defined shell of free metallic atoms surrounding the Earth from 75-110km. The complex chemistry and dynamic behavior of the sodium gas observed by the lidar contributes to understanding chemical processes in the upper atmosphere. New results are indicating the significant connection between the sodium layer density and plasma processes related to the overlying Earth’s ionosphere. Conversely the lidar systems are providing an improved understanding of upper atmosphere behavior in the reentry region of Earth. The Na W/T lidar systems are highly sophisticated instruments requiring careful operations and detailed understanding. The Lidar Consortium project manages and operates three Na W/T systems in geophysically diverse locations on the globe. The Na W/T system at the ALOMAR facility is at 69N and provides observations of the polar upper atmosphere in the presence of aurora and unique polar dynamics. The Na W/T system at USU is at 42N to provide observations of the midlatitude upper atmosphere. Here atmospheric tides are a prevalent feature in the data and much progress on upper atmosphere climate trends have been possible using this instrument. The ALO is at 30S and lies on the leeward side of the Great Andes Mountains. This significant orographic feature produces atmospheric buoyancy waves, known as gravity waves that propagate upward and crash in the mesosphere and lower thermosphere. Thus, ALO is uniquely positioned in a region of very active gravity wave breaking to contribute to studies of atmospheric gravity wave transfer processes. The sophistication of these systems has warranted the development of a new facility called the Consortium Technology Center (CTC) operating at the University of Colorado. The CTC was established in response to the technology needs of the consortium. This element of the consortium is unique and, over the past 5 years, has become an integral part of CRRL by leading the technology innovation and development, supporting CRRL operations, training lidar students and researchers, exploring advanced technology for future lidar, and expediting technology transfer to the science communities. The CRRL project, with its lidar observatories and CTC, has made significant contributions over the past 5 years to middle and upper atmosphere science and lidar technology. The CRRL lidars have proven to be nuclei for expanding collections of correlative instrumentation because of the more comprehensive scientific studies that they enable. ALO, ALOMAR and USU have significant additional ground-based instrumentation because of the clear value of Na W/T lidar measurements for many scientific applications. Groups outside of the CRRL members which have used data from one or more of the CRRL observatories include 41 institutions from 9 countries. Education and training in upper atmosphere science and Na W/T lidar technology is another key aspect of CRRL. As this program is mainly university based, undergraduate, Masters, and Ph.D.-level students participate directly. Over the past 5 years, CRRL universities and affiliated institutes have supported 18 Ph.D., Masters, and undergraduate student research programs, resulting in a total of 12 Ph.D.’s, 5 Masters, and 1 Bachelors graduating and benefiting, at various levels, from CRRL activities.
