Abstract : The quasibiennial oscillation (QBO) of stratospheric winds is the most striking example of mean-flow generation and reversal by the nonlinear interactions of internal waves. Previous studies have used an idealized monochromatic forcing to investigate the QBO. Here we instead force a more realistic continuous wave spectrum. Unexpectedly, spreading the wave energy across a wide frequency range leads to more regular oscillations. We also find that different forcing spectra can yield the same QBO. Multimodal wave forcing is thus essential for understanding wave–mean-flow interactions in nature.
https://hal-amu.archives-ouvertes.fr/hal-03099186 Contributor : Julien CaugantConnect in order to contact the contributor Submitted on : Wednesday, January 6, 2021 - 8:47:03 AM Last modification on : Wednesday, November 3, 2021 - 4:05:56 AM Long-term archiving on: : Wednesday, April 7, 2021 - 6:32:52 PM
P Léard, D Lecoanet, M. Le Bars. Multi-modal excitation to model the Quasi-Biennial Oscillation. Physical Review Letters, American Physical Society, 2020, 125, pp.234501. ⟨10.1103/PhysRevLett.125.234501⟩. ⟨hal-03099186⟩