Evidence for nonlinear development of magnetohydrodynamic scale intermittency in the inner heliosphere

The formation of coherent structures in turbulence is a signature of a developing cascade and therefore might be observable by analyzing inner heliospheric solar wind turbulence. To test this idea, data from the Helios 2 mission, for six streams of solar wind at different heliocentric distances and...

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Autores principales: Greco, A., Matthaeus, W.H., D'Amicis, R., Servidio, S., Dmitruk, P.
Formato: Artículo publishedVersion
Lenguaje:Inglés
Publicado: 2012
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0004637X_v749_n2_p_Greco
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Sumario:The formation of coherent structures in turbulence is a signature of a developing cascade and therefore might be observable by analyzing inner heliospheric solar wind turbulence. To test this idea, data from the Helios 2 mission, for six streams of solar wind at different heliocentric distances and of different velocities, were subjected to statistical analysis using the partial variance of increments (PVI) approach. We see a clear increase of the PVI distribution function versus solar wind age for higher PVI cutoff, indicating development of non-Gaussian coherent structures. The plausibility of this interpretation is confirmed by a similar behavior observed in two-dimensional magnetohydrodynamics simulation data at corresponding dimensionless nonlinear times. © 2012. The American Astronomical Society. All rights reserved.