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Investigating the location and strength of the auroral electrojets using Swarm

Smith, Ashley; Whaler, Kathy; Beggan, Ciaran; Macmillan, Susan. 2016 Investigating the location and strength of the auroral electrojets using Swarm. [Poster] In: ESA Living Planet Symposium, Prague, Czech Republic, 9-13 May 2016. (Unpublished)

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Abstract/Summary

The auroral electrojets are a key space weather phenomenon. They are formed by horizontal Hall currents that flow within the ionospheric polar regions at an altitude of around 115 km. They form ovals around the magnetic poles but their latitudinal position, width, and strength are highly variable. These are governed by geomagnetic activity and solar wind conditions, along with a global ordering by the main magnetic field. Typically, greater geomagnetic activity will cause the electrojets to intensify and move equatorward. This is associated with greater auroral displays in more populated areas but also with potentially severe consequences both on Earth and in space: - geomagnetically Induced Currents (GICs) - disturbance to radio communications and GNSS signals - disruption to navigation applications - increased drag on satellites due to expansion of the atmosphere The auroral electrojet system can be described by the AE activity indices derived from measurements at ground-based magnetic observatories. The accuracy of the AE indices is limited by the observatories' fixed positions, which inhibits the ability to consistently locate the electrojets. Significantly, the indices only cover the Northern hemisphere so do not capture the differences between the Northern and Southern systems. Polar low-Earth orbit satellite observations offer the opportunity to overcome these limitations, by providing excellent latitudinal resolution and coverage equally over both poles. There have been several demonstrations of using satellites to monitor the auroral electrojets: Olsen (1996) using Magsat; Moretto et al (2002) using Oersted, CHAMP, and SAC-C; Juusola et al. (2009) and Vennerstrom and Moretto (2013) using CHAMP; and Hamilton and Macmillan (2013) using Magsat and CHAMP. The results presented here apply the method of Vennerstrom and Moretto (2013) to data from the Swarm mission.

Item Type: Publication - Conference Item (Poster)
NORA Subject Terms: Earth Sciences
Space Sciences
Date made live: 01 Jun 2016 13:28 +0 (UTC)
URI: http://nora.nerc.ac.uk/id/eprint/513731

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