ALEOS addresses ionospheric electrodynamics, with emphasis on the auroral region where the magnetic field lines provide a direct connection between the collisional ionosphere-thermosphere and the collisionless magnetosphere. The three-point measurements of Swarm, conjugate at times with ground data, make possible a systematic examination of the ionospheric current closure associated with aurora. The magnetic field, electric field, and neutral wind data provided by Swarm, together with Pedersen and Hall conductance obtained directly from conjugate radar observations (e.g. EISCAT, AMISR) or indirectly from Swarm data, enable an unprecedented exploration of the ionospheric currents and of their connection to field-aligned currents on both arc and oval scales.

Specifically, ALEOS concentrates on:

(a) Observation of gradients along auroral arcs (in electric field, field-aligned currents, etc), and adjustment of the present, mostly 1D arc models.

(b) Examination of 2D electrodynamics of the aurora, taking full advantage of data from all three Swarm satellites.

(c) Proper consideration of the neutral wind influence on the auroral electrodynamics.

(d) Investigation of the I-T role in the coupled M-I-T system, using both Swarm data and observations from higher altitudes, in particular from the Cluster and THEMIS missions.