2 research outputs found
ENERGY-DISSIPATION DURING A SMALL SUBSTORM
The relative importance of the two most likely modes of input energy
dissipation during the substorm of 8 May 1986, with an onset at 12:14 UT
(CDAW 9E event), is examined here. The combination of data from the
interplanetary medium, the magneto-tail and the ground allowed us, first
of all, to establish the sequence of phenomena which compose this
substorm. In order to calculate the magnetospheric energetics we have
improved the Akasofu model, by adding two more terms for the total
magnetospheric output energy. The first one represents the energy
consumed for the substorm current wedge transformation, supplied by the
asymmetric ring current. This was found to be 39% of the solar wind
energy entering the magnetosphere from the start of the growth phase up
to the end of the expansion phase. The second term represents the energy
stored in the tail or returned to the solar wind. Our results suggest
that the substorm leaves the magnetosphere in a lower energy state,
since, according to our calculations, 23% of the energy that entered
the magnetosphere during the whole disturbance was returned back to the
solar wind. Finally, it is interesting to note that during the growth
phase the driven system grow considerably, consuming 36% of the solar
wind energy which entered the magnetosphere during this early phase of
the substorm