edu.ucar.opensky::articles:43558 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T17:49:50.762379 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.net/ark:/85065/d73b64jm Intermittency assessed through a model of kurtosis–skewness relation in MHD in fast dynamo regimes 2025-05-01T00:00:00Z publication https://n2t.net/ark:/85065/d73b64jm https://doi.org/10.1017/S0022377825000169 Ponty, Y. author Politano, H. author Pouquet, Annick author UCAR/NCAR - Library publisher Intermittency as it occurs in fast dynamos in the magnetohydrodynamics (MHD) framework is evaluated through the examination of relations between normalized moments at third order (skewness $S$ ) and fourth order (kurtosis $K$ ) for both the velocity and magnetic field, and for their local dissipations. As investigated by several authors in various physical contexts such as fusion plasmas (Krommes 2008 Phys. Plasmas 15 , 030703), climate evolution (Sura &amp; Sardeshmukh 2008 J. Phys. Oceano. 38 , 639-647), fluid turbulence or rotating stratified flows (Pouquet et al. 2023 Atmosphere 14 , 01375), approximate parabolic $K(S)\sim S^\alpha$ laws emerge whose origin may be related to the applicability of intermittency models to their dynamics. The results analyzed herein are obtained through direct numerical simulations of MHD flows for both Taylor&#8211;Green and Arnold&#8211;Beltrami&#8211;Childress forcing at moderate Reynolds numbers, and for up to $3.14 \times 10^5$ turn-over times. We observe for the dissipation $0.2 \lesssim \alpha \lesssim 3.0$ , an evaluation that varies with the field, the forcing and when filtering for high-skewness intermittent structures. When using the She &amp; L&#233;v&#234;que (1994) Phys. Rev. Lett. 72 , 336-339 intermittency model, one can compute $\alpha$ analytically; we then find $\alpha \approx 2.5$ , clearly differing from a (strict) parabolic scaling, a result consistent with the numerical data. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication <span style="font-family:Arial;font-size:10pt;font-style:normal;" data-sheets-root="1">Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</span> None eng geoscientificInformation