Using k-Means Cluster Analysis to find and classify Ion Density
Irregularities consistent with Equatorial Plasma Bubbles from Multi-year
Formosat-5 Advanced Ionospheric Probe observations
Abstract
This work explores the results of applying Square Euclidean and
Correlation k-means cluster analysis on ion density irregularity
profiles observed by the Advanced Ionospheric Probe (AIP) onboard the
Formosat-5 (F-5) satellite from November 2017 to November 2020. The
Square Euclidean cluster analysis yielded separate clusters each for ion
density irregularities consistent with Equatorial Plasma Bubbles (EPBs)
occurring over the southern low-latitude, northern low-latitude and
equator. The Correlation k-means cluster analysis only yielded one
cluster characterized by ion density irregularities consistent with EPBs
occurring over the equator. Thus, this work suggests that a cluster
analysis preferably a Square Euclidean Cluster analysis can be used to
find and classify ion density irregularities consistent with EPBs. This
work also shows that the F-5/AIP can perform multi-year observations of
ion density irregularities at ~710 km altitude and at
~2230 pm local-time that are consistent with
irregularities due to EPBs.