New Observations of Noctilucent Clouds (NLC) and their environment over Alaska

We present new observations of noctilucent clouds (NLCs, or polar mesospheric clouds, PMCs) and their environment made with colocated Rayleigh and resonance lidars at Poker Flat Research Range (PFRR), Chatanika, Alaska (65°N, 147° W). The Rayleigh Density Temperature Lidar (RDTL) at PFRR has been extended to a three-channel system and yields measurements with signals a factor of 3-4 higher than the previous single-channel systems. This higher signal yields NLCs/PMCs measurements at higher resolution and neutral density measurements above the altitude of the NLCs/PMCs. This allows us to determine the neutral density profile over altitudes above, spanning, and below the NLCs/PMCs. The Sodium Resonance Wind Temperature Lidar (SRWTL) provides measurements of temperature and wind above the NLCs. Combining the RDTL neutral density profile and the SRWTL temperature measurements, we determine the temperature profile over the altitude range of the clouds. We present results from observations made during northern summers of 2020 and 2021. We examine the temperature in the NLCs/PMCs in the light of recent investigations of water releases in the mesosphere.