Atmospheric Gravity Waves in ADM-Aeolus Wind Lidar Observations.

Abstract:

ADM-Aeolus is a European Space Agency (ESA) Earth Explorer mission which launched in August 2018 carrying the first Doppler wind lidar in space. Designed to provide global coverage of direct wind observations in the lowermost 30km of the atmosphere, Aeolus provides us with a unique opportunity to study the propagation of gravity waves (GWs) from the surface to the tropopause and UTLS. Existing space-based measurements of GWs in this height range are spatially limited and, where available, use temperature as a proxy for wind perturbations, and thus space-borne wind lidars such as Aeolus will transform our understanding of this critically-important dynamical process.

Here, we present the first systematic study of GWs in Aeolus data. We examine important regional case studies as well as providing a broader global picture of GW activity. We see a number of interesting features such as strong wave refraction and tropospheric GW source and sink mechanisms which were previously not accessible to global-scale study. Our results are validated against ERA5 reanalysis and against temperature-based stratospheric observations from the AIRS and SABER satellite instruments, and have broad implications for atmospheric modelling and our understanding of atmospheric dynamics.