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arXiv · 2411.08427

Large-scale self-organisation in dry turbulent atmospheres

Alexandros Alexakis·Raffaele Marino·Pablo D. Mininni·Adrian van Kan·Raffaello Foldes·Fabio Feraco
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Abstract

How turbulent convective fluctuations organise to form large-scale structures in planetary atmospheres remains a question that eludes quantitative answers. The assumption that this process is the result of an inverse cascade was suggested half a century ago in two-dimensional fluids, but its applicability to atmospheric and oceanic flows remains heavily debated, hampering our understanding of the energy balance in planetary systems. We show with direct numerical simulations of spatial resolutions of 122882 $\times$ 384 points that rotating and stratified flows can support a bidirectional cascade of energy, in three dimensions, with a ratio of Rossby to Froude numbers comparable to that of the Earth's atmosphere. Our results establish that in dry atmospheres spontaneous order can arise via an inverse cascade to the largest spatial scales.

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Alexandros Alexakis, Raffaele Marino, Pablo D. Mininni, Adrian van Kan, Raffaello Foldes, Fabio Feraco. 2024-11-13. Large-scale self-organisation in dry turbulent atmospheres. https://arxiv.org/abs/2411.08427

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