Skip to main content
Article thumbnail
Location of Repository

Superposed epoch analysis of the ionospheric convection evolution during substorms: onset latitude dependence

By Adrian Grocott, J.A. Wild, Steve E. Milan and Tim K. Yeoman

Abstract

This paper was published as Annales Geophysicae, 2009, 27 (2), pp. 591-600. It is also available from http://www.ann-geophys.net/27/591/2009/angeo-27-591-2009.htmlUsing data from the Super Dual Auroral Radar Network (SuperDARN) we investigate the ionospheric convection response to magnetospheric substorms. Substorms were identified using the Far Ultraviolet (FUV) instrument on board the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft, and were then binned according to the magnetic latitude of their onset. A superposed epoch analysis of the ionospheric convection patterns for each onset-latitude bin was then performed using radar data for the interval 60 min before onset to 90 min after. It is found that lower onset-latitude substorms are associated with generally more enhanced convection than the higher latitude substorms, although they suffer from a significant localised reduction of the flow in the midnight sector during the expansion phase. Higher-latitude substorms are associated with a significant and rapid increase in the nightside convection following substorm onset, with all onset-latitude bins showing an enhancement over onset values by ~60 min into the expansion phase. A rudimentary inspection of the concurrent auroral evolution suggests that the duration of the flow reduction following substorm onset is dependent on the strength and duration of the expansion phase aurora and its associated conductivity enhancement

Publisher: Copernicus Publications on behalf of the European Geosciences Union
Year: 2009
DOI identifier: 10.5194/angeo-27-591-2009
OAI identifier: oai:lra.le.ac.uk:2381/7818
Journal:

Suggested articles

Citations

  1. (2009). 600 A. Grocott et al.: Ionospheric convection during substorms
  2. (2007). A decade of the Super Dual Auroral Radar Network (SuperDARN): scientific achievements, new techniques and future directions, doi
  3. (2009). A superposed epoch analysis of auroral evolution during substorm growth, onset and recovery: open magnetic flux control of substorm intensity, Ann. Geophys., in press, doi
  4. (2007). A superposed epoch study of SuperDARN convection observations during substorms, doi
  5. (2000). Combined CUTLASS, EISCAT and ESR observations of ionospheric plasma flows at the onset of an isolated substorm, doi
  6. (1996). Current disruption in the Earth’s magnetosphere: Observations and models, doi
  7. (1992). Excitation and decay of solar wind-driven flows in the magnetosphere-ionosphere system, doi
  8. Far ultraviolet imaging from the IMAGE spacecraft. 2. Wideband FUV imaging, doi
  9. (1998). Large-scale imaging of highlatitude convection with Super Dual Auroral Radar Network HF radar observations, doi
  10. (1997). Magnetotail reconnection rate during magnetospheric substorms, doi
  11. (1998). Near Earth Plasma Sheet Penetration and Geomagnetic Disturbances, in: New Perspectives on the Earth’s Magnetotail, edited by doi
  12. (1996). Neutral line model of substorms: Past results and present view, doi
  13. (1998). Plasma Flow in the Coupled Magnetosphere-Ionosphere System and Its Relationship to the Substorm Cycle, doi
  14. (1995). Radar observations of auroral zone flows during a multiple-onset substorm, doi
  15. (2004). Statistical study of high-latitude plasma flow during magnetospheric substorms, doi
  16. (1999). Substorm influence on the ionospheric electric potentials and currents, doi
  17. (2004). Substorm onset observations by IMAGE-FUV, doi
  18. (1996). Substorm-associated changes in large-scale convection during the doi
  19. System design,
  20. (2008). Tail Reconnection Triggering Substorm Onset, doi
  21. (1964). The development of the auroral substorm, doi
  22. (2008). The influence of magnetospheric substorms on SuperDARN radar backscatter, doi
  23. (2002). Towards a synthesis of substorm electrodynamics: HF radar and auroral observations, doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.