Lidars provide temperature observations for the mesosphere-lower thermosphere that are unique in terms of both vertical and temporal resolution. Sox et al.  present temperature measurements from a new high power, large aperture Rayleigh lidar that extends the vertical range to 115 kilometers. These new measurements are unique in the world. Over 19 nights during one year, direct comparisons were made with a co-located sodium lidar, and the two measurements overlap over altitudes 80 to 110 kilometers. Results show best agreement over altitudes 85 to 95 kilometers (with mean differences of approximately 1 Kelvin), with larger differences above and below that remain to be investigated. Being able to probe temperatures into the lower thermosphere (up to 115 kilometers) with continuous nightly measurement will be especially valuable for studying the transition across the turbopause.
Citation: Sox, L., Wickwar, V. B., Yuan, T., & Criddle, N. R. . Simultaneous Rayleigh‐scatter and sodium resonance lidar temperature comparisons in the mesosphere‐lower thermosphere. Journal of Geophysical Research: Atmospheres, 123. https://doi.org/10.1029/2018JD029438
—William Randel, Editor, JGR: Atmospheres