Gravity Wave Activity and Sudden Stratospheric Warmings in Alaska

In this poster we present observations of gravity waves made with Rayleigh and resonance lidars in winters in the upper stratosphere-mesosphere (USM, 40-75 km) and upper mesosphere-lower thermosphere (UMLT, 85-95 km). The measurements are reported from poker Flat Research Range, Chatanika, Alaska (65°N, 147°W) in the winters of 2018-19, 2019-20, 2020-21, and 2021-22. Upgrades in the Rayleigh lidar and deployment of a sodium Doppler wind-temperature lidar in 2017 has extended the scope of the gravity wave measurements to higher altitudes than in previous studies. These winters are characterized by Sudden Stratospheric Warmings (SSWs) in 2018-19 and 2020-21 with disrupted polar stratospheric vortex, a strong polar stratospheric vortex with ozone depletion in 2019-20, and a strong polar stratospheric vortex in 2021-22. We detect suppressed gravity wave activity in winter 2018-2019 (NDJF) compared to the other winters in both the USM and UMLT. We analyze the observations in terms of the wind regimes and discuss the gravity wave activity in terms of vertical coupling between the stratosphere, mesosphere and thermosphere.