Identification

Title

Ionospheric oscillations with a quasi‐period of ∼6 hr during intense magnetic storms

Abstract

We study the variations of the topside ionospheric ion density measured by Defense Meteorological Satellite Program satellites during the intense magnetic storm on 7-10 November 2004. It is found for the first time that quasi-periodic enhancements in the ion density with a period of SIM;6 hr occur nearly simultaneously at 0630, 0830, and 0930 local time in the dawn sector during the storm main phase with southward interplanetary magnetic field (IMF). The quasi-periodic density enhancements extend from the southern subauroral latitudes to the northern subauroral latitudes. In the dusk sector, the topside ion density during the storm main phase is increased at middle latitudes for SIM;12 hr but shows decrease or relatively small increase over the magnetic equator, indicating that penetration electric fields dominate the ion density redistribution. Similar quasi-periodic enhancements in the topside ion density are also observed in the dawn sector during other intense magnetic storms. The solar wind and IMF do not have quasi-periodic variations in this storm case. Periodic processes in geospace, such as periodic substorms in the magnetosphere, waves and tides in the atmosphere, and traveling ionospheric disturbances, cannot explain the observed periodic enhancements of the ionospheric ion density. We suggest that the magnetosphere-ionospheric-thermospheric system may have an intrinsic period of SIM;6 hr and that oscillations of the magnetosphere-ionospheric-thermospheric system with this period can be excited during intense magnetic storms, although the mechanisms for the generation of the long-periodic oscillations are not understood.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d75x2dtg

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

2023-01-01T00:00:00Z

Frequency of update

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Conformity

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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