Close to the DP1 current system the magnetic perturbation is predominantly a negative H
perturbation associated with the sudden intensification of the westward DP1 electrojet. If we approximate
the electrojet by a line current then the Z component reveals the location of the electrojet
relative to the station. This is shown in the figure which illustrates typical ground magnetic
perturbations at different locations relative to the DP1 electrojet (Rostoker et al., 1980). Examples
of an isolated and a pair of DP1 events can be seen in
Further away from the DP1 current system the magnetic perturbation is determined by the field-aligned currents that feed the DP1 electrojet (Clauer and McPherron, 1974). Note that Halley may also see this type of signature when the DP1 currents flow far poleward of the station.
|BAS Homepage||UASD Homepage||Navigator|