USU-CSU Na Lidar Data

The naturally existing mesospheric Na layer, overlapping the upper mesosphere and lower thermosphere, provides an excellent tracer for lidar remote sensing. The Na Doppler lidar technique is designed to measure neutral temperature and wind profiles in the mesopause region (~ 80-110 km) by observing the thermal broadening and Doppler shift of the atomic Na fluorescence spectrum. Relocated from Colorado State University (CSU), the Na lidar at Utah State University (USU) has been operating since the summer of 2010, for roughly 1000 hours per year. Enabled by a pair of Faraday filters, it has a unique daytime observation capability to study not only small-scale dynamics features, but also large scale tidal and planetary wave activities. Combined with the lidar database at CSU, this project has the longest mesopause region temperature database in the world (32 years and counting). This invaluable database has enabled several long-term trend studies in the upper atmosphere, which is mostly related to the increasing CO2 diffusion from the troposphere into the upper atmosphere and the stratosphere contraction.

The CSU observations of Na density and temperature from 80-100 km started on Aug. 25, 1989, in Fort Collins, CO (40.6N, 105.1W) and ended in Mar 2010 before relocating to Logan Utah. From 1990 to 2001, the lidar deployed one vertical, two-frequency beam. By 1996 the development of the three-frequency technique and the Na Faraday filter upgraded the system to include line-of-sight (LOS) wind measurement and capability for observation under sunlit conditions. Tilting and directing multiple beams in different directions allows measurements of temperature, sodium density, and line-of-sight wind at the specified directions both day and night, weather permitting. In August 2015 data were analyzed with the regular resolution at 60 min and 2 km (see http://millstonehill.haystack.mit.edu), and the nocturnal data in higher resolution, at 10 min and 1 km for data between 1990 and 2005. The analysis of CSU data after September 2006 at the higher resolution of 1 km and depending on the size of the receiving telescope used, either at 10 min or at 2.5 min can be found in this site.

The user of this dataset is required to acknowledge the source: ’Data used with permission from “USU-CSU Na Lidar” (https://doi.org/10.15142/T33H26)’.