  The magnetopause is a current sheet forming the boundary between the
geomagnetic field on one side and the shocked solar wind on the other side.
This paper discusses properties of the low-latitude dawn and dusk flanks of the
magnetopause. The reported results are based on a large number of measurements
obtained by the Cluster satellites during magnetopause traversals. Using a
combination of single-spacecraft and multispacecraft techniques, we calculated
macroscopic features such as thickness, location, and motion of the
magnetopause. The results show that the typical flank magnetopause is
significantly thicker than the dayside magnetopause and also possesses a
pronounced and persistent dawn-dusk asymmetry. Thicknesses vary from 150 to
5000 km, with an median thickness of around 1400 km at dawn and around 1150 km
at dusk. Current densities are on average higher on dusk, suggesting that the
total current at dawn and dusk are similar. Solar wind conditions and the
interplanetary magnetic field cannot fully explain the observed dawn-dusk
asymmetry. For a number of crossings we were also able to derive detailed
current density profiles. The profiles show that the magnetopause often
consists of two or more adjacent current sheets, each current sheet typically
several ion gyroradii thick and often with different current direction. This
demonstrates that the flank magnetopause has a structure that is more complex
than the thin, one-dimensional current sheet described by a Chapman-Ferraro
layer.
