Primary joint statistical seismic influence on ionospheric parameters
recorded by the CSES and DEMETER satellites
Abstract
Oppositely to a previous statistical work using a single time resolution
of the total ion density measured onboard the DEMETER satellite, this
work deals with statistical seismo-ionospheric influences by comparing
different parameters and various time resolutions. The O+ density and
electron density recorded by the CSES satellite for more than one year
and by the DEMETER satellite for about 6.5 years have been utilized to
globally search ionospheric perturbations with different time
resolutions. A comparison is automatically done by software between the
occurrence of these ionospheric perturbations determined by different
data sets, and the occurrence of earthquakes under the conditions that
these perturbations occur at less than 1500 km and up to 15 days before
the earthquakes. Combined with statistical results given by both
satellites, it is shown that the detection rate r of earthquakes
increases as the data time resolution and the earthquake magnitude
increase and as the focal depth decreases. On average, the number of
perturbations is higher the day of the earthquake, and then smoothly
decreases the days before, which is independent of either ionospheric
parameters or time resolutions. The number of right alarms is high near
the South Atlantic Magnetic Anomaly area but its relationship with
seismic activities is weak. The ion density tends to be more sensitive
to seismic activities than the electron density but this needs further
investigations. This study shows that the CSES satellite could
effectively register ionospheric perturbations due to strong EQs as the
DEMETER satellite does.