Identification

Title

Turbulent cascades, transfer, and scale interactions in magnetohydrodynamics

Abstract

The nature of the interactions between different scales in magneto-hydrodynamic (MHD) turbulence is important for the understanding of the behaviour of magnetized astrophysical, geophysical and industrial flows in a turbulent state. In this paper, we review some recent results in the study of locality of interactions in turbulent flows and we address some of the questions that arise. We examine the cascade of ideal invariants in turbulent MHD flows by examining the transfer functions. We show new results indicating that the nonlocal behaviour of the energy transfer in MHD is the result of a correlation between the velocity and magnetic fields. This nonlocality disappears if we randomize the phases of the two fields keeping the hydrodynamic and magnetic helicities fixed. The cascade of magnetic helicity is also investigated, with special focus on the fate of the small-scale helicity and its coupling with the large-scale flow. These results have implications for dynamo action, in particular for the commonly used distinction between large- and small-scale dynamos. The long-range interactions that exist in MHD flows also raise the question of the existence of universality in MHD, both in the kinematic dynamo regime as well as in the turbulent steady state.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7gm87js

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

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Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2007-08-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact