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arXiv · 2309.13953

Jupiter's equatorial quasi-quadrennial oscillation forced by internal thermal forcing

Yuchen Lian·Xianyu Tan·Yongyun Hu
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Abstract

Observations have shown that there exists downward propagation of alternating westward/eastward jets in Jupiter's equatorial stratosphere, with a quasi-period between four and six years. This phenomenon is generally called the quasi-quadrennial oscillation (QQO). Here, we simulate the QQO by injecting isotropic small-scale thermal disturbances into a three-dimensional general circulation model of Jupiter. It is found that the internal thermal disturbance is able to excite a wealth of waves that generate the equatorial QQO and multiple jet streams at middle and high latitudes of both hemispheres. The dominant wave mode in generating the QQO-like oscillation is that with a zonal wavenumber of 10. Inhomogeneous evolution of potential vorticity favors the emergence of the off-equatorial zonal jets. The off-equatorial jets migrate to the equator, strengthen the deep equatorial jets, and result in the prolonging of the QQO-like oscillations.

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Yuchen Lian, Xianyu Tan, Yongyun Hu. 2023-09-25. Jupiter's equatorial quasi-quadrennial oscillation forced by internal thermal forcing. https://arxiv.org/abs/2309.13953

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