Deep rotating convection generates the polar hexagon on Saturn
| Autor: | Yadav, Rakesh Kumar, Bloxham, Jeremy |
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| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | PNAS June 23, 2020 117 (25) 13991-13996 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1073/pnas.2000317117 |
| Popis: | Numerous land and space-based observations have established that Saturn has a persistent hexagonal flow pattern near its north pole. While observations abound, the physics behind its formation is still uncertain. Although several phenomenological models have been able to reproduce this feature, a self-consistent model for how such a large-scale polygonal jet forms in the highly turbulent atmosphere of Saturn is lacking. Here we present a 3D fully-nonlinear anelastic simulation of deep thermal convection in the outer layers of gas giant planets which spontaneously generates giant polar cyclones, fierce alternating zonal flows, and a high latitude eastward jet with a polygonal pattern. The analysis of the simulation suggests that self-organized turbulence in the form of giant vortices pinches the eastward jet, forming polygonal shapes. We argue that a similar mechanism is responsible for exciting Saturn's hexagonal flow pattern. Comment: 11 pages, 4 main and 5 supplementary figures, 1 animation, 42 references |
| Databáze: | arXiv |
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