IAMAS Workshop on “Layered Phenomena in the Mesopause Region”
The Atmospheric Lidar Observatory (ALO) Rayleigh-scatter lidar has been operated for 11 years on the Utah State University (USU) campus (41.7o N 111.8o W). During the morning of 22 June 1995 a noctilucent cloud (NLC) was observed with the lidar well away from the twilight periods when NLCs are visible. It lasted for approximately one hour. This observation and a second in 1999 [Wickwar et al., 2002] are very significant because they show the penetration of NLCs equatorward of 50°, which may have important implications for global change. Temperature profiles calculated at hourly intervals were at least 20 K cooler than the 11-year June climatological average for ALO near the NLC altitude. These cool temperatures arose, in part, because of a major temperature oscillation.
Herron, J., & Wickwar, V. (2004, September 14). An Earlier Lidar Observation of a Noctilucent Cloud above Logan, Utah (41.7°N) (Invited Poster). Presented at the IAMAS Workshop on “Layered Phenomena in the Mesopause Region”,, Cambridge, UK.