Idealized Quasi-Biennial Oscillations in an Ensemble of Dry GCM Dynamical Cores

摘要: AbstractThe paper demonstrates that quasi-biennial oscillation (QBO)-like oscillations can be simulated in an ensemble of dry GCM dynamical cores are driven by a simple Held–Suarez temperature relaxation and low-level Rayleigh friction. The tropical stratospheric circulations four cores, which options NCAR’s Community Atmosphere Model, version 5 (CAM5), intercompared. These the semi-Lagrangian (SLD) Eulerian (EUL) spectral transform, finite-volume (FV), element (SE) cores. investigates how model design choices impact wave generation, propagation, dissipation mechanisms equatorial region. SLD, EUL, SE develop spontaneous QBO-like upper stratosphere, whereas FV does not sustain oscillation. Transformed Eulerian-mean (TEM) analyses reveal resolved waves dominant drivers QBOs. However, Eliassen–Palm flux divergence is strongly counteracted TEM momentum ...