Evolution of auroral asymmetries in the conjugate hemispheres during two substorms

[ 14 ] The Pedersen currents are primarily meridional and hence primarily close the east-west oriented upward and downward field-aligned current regions, except in the electric

[ 5 ] Figure 2 shows a selection of near-simultaneous images of the entire auroral ovals in the northern (left) and southern (right) hemispheres, observed between 11:24 and 12:10 UT

[ 13 ] Our results (Figure 1) show clearly that the average substorm onset locations in the two hemispheres based on the IMAGE FUV list of substorms follow a sine function of IMF c

(a) Snapshot of open (solid, dashed, dotted) field lines and one reconnected closed (thick) field line under the influence of the magnetic tension force (thick grey arrows) from IMF B

B) Average substorm MLT locations for 18 ◦ bins of IMF θ c for substorms identified from Polar data in the northern hemisphere. D) ∆MLT between the southern and northern

(C) The image pair mapped to a rectangular magnetic grid. The northern aurora has been longitudinal shifted - 1.3 MLT. Regions of non-conjugate aurora are indicated with solid

sion force gives rise to a current generator and as part of these currents close in the ionosphere (Figure  10.1b) interhemispheric differences in auroral brightness should be

Figure 2. The relative displacement, ∆MLT, of substorm auroral features based on A) Visual inspection, B) 1D cross correlation, C) 2D correlation. Grey diamonds are all data,