Ground-based Auroral Hiss Recorded at Northern Finland with Reference to
Magnetic Substorms
Abstract
VLF auroral hiss at Kannuslehto (KAN), Finland has been analyzed with a
reference to progress of 98 isolated magnetic substorms. During 11
winter months of 2015-2018, 91 of them were accompanied by the auroral
hiss during the substorm growth phase. No auroral hiss was recorded
during the expansion and recovery phases. We found auroral hiss was
observed under rising polar cap PC index showing an increasing input of
the solar wind energy into the magnetosphere during the substorm growth
phase. We also found that KAN was mapped to the vicinity of enhanced
Field Aligned Currents (FACs) during the auroral hiss occurrence. For
the first time, it was established that the auroral VLF hiss generation
in the equatorial part of the auroral oval (KAN location) is a typical
signature of a substorm phase.