Identification

Title

Formation of AlfvÃ©n wave ducts by magnetotail flow bursts

Abstract

Geomagnetic activity in Earth's outer magnetosphere stimulates intense and sometimes explosive flows of electromagnetic power propagating earthward as Alfven waves. Observations show that among its various magnetospheric sources, Alfvenic Poynting flux from the magnetotail reaches the ionosphere with the greatest intensity. Dayside fluxes are statistically weaker though more persistent. Flankside fluxes are weakest. We show using global magnetohydrodynamic simulations that these distributions can be attributed to the formation (or not) of meridionally narrow, relatively uniform, low Alfven conductance channels that efficiently transmit Alfvenic power to the near-Earth space. These Alfven ducts form naturally at the heads of flow bursts in the magnetotail but not in flankside flux tubes, where the transmission of Alfvenic power is strongly attenuated by reflections at large conductance gradients along the propagation path. The results elucidate the underlying physics that control efficient transmission of electromagnetic power from the magnetotail to low altitude to power Alfvenic aurora.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7kd22qj

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

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2022-09-01T00:00:00Z

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