Post on 31-Dec-2015
description
Texture of the Solar-Wind PlasmaTurbulence is confined to flux tubes.
Median diameter is ~5x105 km.
Plasma in each flux tube differs.
Field-line wandering is confined to inside a flux tube.
Flux tubes move independently in themacroscale flow of the solar wind.The turbulence is inside! If created by the granules, this patternhas survived intact for ~100 hoursin the presence of MHD turbulence.
Bruno et al. Picture of Flux Tubes and the Parker Spiral
Discontinuities in the Solar Wind
Magnetic-Field Hodogram
Time-Averaging: Turbulence Versus the Flux Tubes
Tracing these Flux Tubes back to the Surface of a Rotating SunThe flux-tubesizes correspondto solar granules.
Cellular Solar WindField direction differs from cell to cell (panel 1)
Cells move independently (panel 2)
Plasma properties differ from cell to cell (panels 3 + 4)
Electron heat flux differs cell to cell (not shown)
No plasma mixing across cell walls:Cell walls are boundaries to the turbulence. . Turbulence-in-a-Box .
The Flux Tubes Move Independent of Each Other in the Solar-Wind FlowWhere there are jumps in the field direction, there are jumps in the flow velocity.
The different flux tubes are moving at different speeds.
Discontinuities Drastically Affect the Turbulence AnalysisDiscontinuity-free intervals yield different answers!