Electric field instrument first data

This is a time-lapse movie of some of the first ion images observed by Swarm’s electric field instrument. Spanning more than an orbit, the images in this movie demonstrate the capability of the instrument to operate under a wide range of plasma conditions. It provides ion velocity and temperature, roughly represented by the position and width of the ion spot in each panel. Motion of this spot reveals ion flow and electric field variability, and increases in the spot width represent heating of ions. Taken together, the horizontal and vertical sensors provide a basis for measuring 3D ion drift, which can be combined with magnetic field information to obtain values of the electric field in the ionosphere.