1: Asymmetric Geospace

When and why is the aurora in the two hemispheres asymmetric?

  • What controls differences in auroral intensities?
  • How common are inter-hemispherical currents?
  • How and when are the open-closed boundaries in the two hemispheres asymmetric?
  • Does this affect the inter-hemispherical current system?
  • Are day- and night-side reconnection rates balanced in the two hemispheres?
  • What controls the difference in convection pattern in the two hemispheres?
  • How and when are the auroral electrojets asymmetric?
  • Do the asymmetric substorm onset locations always disappear during expansion phase?
  • What determines when polar arcs are non-conjugate?

To address these unresolved questions about the Earth-space coupling we will analyze simultaneous auroral images obtained by Polar and IMAGE. SuperMAG provides data of validated ground magnetic field perturbations from more than 300 stations in both hemispheres. The SuperMAG data enables us to address differences in the electrojets as well as inter-hemispherical currents, which are important inputs to G2. The BCSS will also have experts in analyzing convection data from SuperDARN from both hemispheres (Gjerloev et al. 2007, Oksavik et al., 2010) and Cluster data (Haaland et al., 2008). Open-closed boundaries are also defining day- and night-side reconnection rates, and combined with reconnection data from Cluster (e.g., Østgaard et al., 2009) we aim at characterizing the dynamics of the Dungey cycle for various conditions.

 Go to Overview to read more about the G1 work.