Multi-scale waves in sound-proof global simulations with EULAG

• Autorzy: Prusa J.M. , Gutowski W.J.
• Języki publikacji: EN

Abstrakty

EN

EULAG is a computational model for simulating flows across a wide range of scales and physical scenarios. A standard option employs an anelastic approximation to capture nonhydrostatic effects and simultaneously filter sound waves from the solution. In this study, we examine a localized gravity wave packet generated by instabilities in Held-Suarez climates. Although still simplified versus the Earth's atmosphere, a rich set of planetary wave instabilities and ensuing radiated gravity waves can arise. Wave packets are observed that have lifetimes ≤ 2 days, are negligibly impacted by Coriolis force, and do not show the rotational effects of differential jet advection typical of inertia-gravity waves. Linear modal analysis shows that wavelength, period, and phase speed fit the dispersion equation to within a mean difference of ∼ 4 per cent, suggesting an excellent fit. However, the group velocities match poorly even though a propagation of uncertainty analysis indicates that they should be predicted as well as the phase velocities. Theoretical arguments suggest the discrepancy is due to nonlinearity - a strong southerly flow leads to a critical surface forming to the southwest of the wave packet that prevents the expected propagation.

Słowa kluczowe

EN

anelastic; gravity waves; baroclinic instability; global model

• Wydawca: Instytut Geofizyki PAN ; Springer
• Czasopismo: Acta Geophysica
• Rocznik: 2011
• Tom: Vol. 59, no. 6
• Strony: 1135--1157
• Opis fizyczny: Bibliogr. 36 poz.

Twórcy

autor

Prusa J.M.

autor

Gutowski W.J.

• Teraflux Corporation, Boca Raton, FL, USA,

Bibliografia

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