Statistical properties of Charney-Hasegawa-Mima zonal flows

• A theoretical interpretation of numerically generated probability density functions (PDFs) ofintermittent plasma transport events in unforced zonal flows is provided within the Charney-Hasegawa-Mima (CHM) model. The governing equation is solved numerically with variousprescribed density gradients that are designed to produce different configurations of parallel andanti-parallel streams. Long-lasting vortices form whose flow is governed by the zonal streams. It isfound that the numerically generated PDFs can be matched with analytical predictions of PDFsbased on the instanton method by removing the autocorrelations from the time series. In manyinstances, the statistics generated by the CHM dynamics relaxes to Gaussian distributions for boththe electrostatic and vorticity perturbations, whereas in areas with strong nonlinear interactions it isfound that the PDFs are exponentially distributed.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

NATURVETENSKAP  -- Fysik -- Fusion, plasma och rymdfysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Fusion, Plasma and Space Physics (hsv//eng)

Nyckelord

Statistical properties of flows

Charney-Hasegawa-Mima

Zonal flows

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art (ämneskategori)

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