Group seminar on 27. June, 14:15 CET

Vertical momentum fluxes of equatorial waves

Valentino Neduhal

The transfer of momentum by atmospheric waves is an important process in the global momentum budget of the atmosphere. As the waves propagate upward and dissipate, they provide forcing for large-scale atmospheric flows, such as the quasi-biennial oscillation (QBO) in the tropical stratosphere. However, the contribution to the momentum budget of different types of resolved waves, such as Kelvin, equatorial Rossby, mixed Rossby-gravity, and inertia-gravity waves across scales, is still highly uncertain. This talk will provide an overview of the methods typically used to compute momentum fluxes from observations and model outputs, along with their assumptions and errors. We will also introduce a novel method for the computation of regime-dependent momentum fluxes, which also provide momentum flux spectra as a function of pressure altitude. The new method is applied to the operational ECMWF data and compared with previous studies.