University of Sussex
Browse

File(s) under permanent embargo

Asymmetric response of the topside ionosphere to large-scale IGW generated during the November 30, 1979, substorm

journal contribution
posted on 2023-06-08, 09:26 authored by AT Karpachev, GF Deminova, Natalia BeloffNatalia Beloff, Tobia Carozzi, PF Denisenko, M Lester, T Karhunen
We used bottomside ground observations and topside sounding data from the Intercosmos-19 satellite to study a Travelling Ionospheric Disturbance (TID) that occurred in response to Large-Scale Internal Gravity Wave (LSIGW) propagation during a substorm on November 30, 1979. We built a global scheme for the wavelike ionospheric variations during this medium substorm (AEmax 800 nT). The area where the TID was observed looks like a wedge since it covers the nighttime hours at subauroral latitudes but contracts to a 02 h local sector at low latitudes. The ionospheric response is strongly asymmetric because the wedge area and the TID amplitude are larger in the winter hemisphere than in the summer hemisphere. Clear evidence was obtained indicating that the more powerful TID from the Northern (winter) hemisphere propagated across the equator into the low latitude Southern (summer) hemisphere. Intercosmos-19 observations show that the disturbance covers the entire thickness of the topside ionosphere, from hmF2 up to at least the 1000 km satellite altitude at post-midnight local times. F-layer lifting reached 200 km, Ne increases in the topside ionosphere by up to a factor of 1.9 and variations in NmF2 of both signs were observed. Assumptions are made concerning the reason for the IGW effect at high altitudes in the topside ionosphere. The relationship between TID parameters and source characteristics determined from a global network of magnetometers are studied. The role of the dayside cusp in the generation of the TID in the daytime ionosphere is discussed. The magnetospheric electric field effects are distinguished from IGW effects. Research Highlights The global scheme for the large-scale TID propagation during a substorm is built. TID covers the entire thickness of the topside ionosphere. The area where the TID is observed looks like a wedge directed to the equator. TID area and amplitude are larger in the winter hemisphere than in the summer hemisphere. The more powerful TID from the winter hemisphere propagates into the summer hemisphere. Keywords: Substorm; Topside ionosphere; Internal gravity wave; IGW; Travelling ionospheric disturbance; TID

History

Publication status

  • Published

Journal

Journal of Atmospheric and Solar-Terrestrial Physics

ISSN

1364-6826

Publisher

Elsevier

Issue

5-6

Volume

73

Page range

567-577

Pages

11.0

Department affiliated with

  • Informatics Publications

Full text available

  • No

Peer reviewed?

  • Yes

Legacy Posted Date

2012-05-14

Usage metrics

    University of Sussex (Publications)

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC