Identification

Title

Alfvénic heating in the cusp ionosphere-thermosphere

Abstract

The effect of electromagnetic variability on cusp-region ionosphere-thermosphere heating is examined. The study is motivated by observed correlations between anomalous thermospheric density enhancements at F region altitudes and small-scale field-aligned currents, previously interpreted as evidence of ionospheric Alfven resonator modes. Height-integrated and height-dependent heating rates for Alfven waves incident from the magnetosphere at frequencies from 0.05 to 2 Hz and perpendicular wavelengths from 0.5 to 20 km have been calculated. The velocity well in Alfven speed surrounding the F region plasma density maximum facilitates energy deposition by slowing, trapping, and intensifying resonant waves. The Alfvenic Joule heating rate maximizes at the resulting resonances. F region Joule heating resulting from quasistatic and Alfvenic variability with the same root-mean-square amplitude in the F region are shown to be comparable. At the same time, Alfvenic variability deposits little electromagnetic power in the E region, whereas quasistatic variability greatly enhances E region heating. When measured electric and magnetic fields are used to constrain the amplitude and spectral content of superposed Alfven waves incident from the magnetosphere, the calculated F region heating rate ranges from 5 to 10 nW/m(2).

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7bk1gc6

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

2018-12-01T00:00:00Z

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