Ionospheric Disturbances observed over the Peruvian sector during the
Mother’s Day Storm (G5-level) on May 10-12, 2024
Abstract
This article presents the recent extreme and rare G5-level geomagnetic
storm (Mother’s Day Storm) effects on the equatorial and low-latitude
ionosphere observed at the Peruvian sector by the Jicamarca (11.9°S,
76.8°W, magnetic dip 1°N) incoherent scatter radar and associated
instruments. This storm was produced by multiple Earth-directed coronal
mass ejections, which generated significant modifications in the Earth’s
magnetic field, leading to the Sym-H of ~-518 nT. On the
dayside, due to the strong eastward penetration electric field, vertical
plasma drift and equatorial electrojet (EEJ) enhanced for 2-3 hours and
remained consistent at values of ~95 m/s and 260 nT
between 1700 and 1900 UT (1200 and 1500 LT). At the same time, vertical
E B plasma drift uplifted the equatorial ionosphere, producing the
dusk-side super plasma fountain and transferring electron density to
higher latitudes. A huge increase (~1325 %) in electron
density (from 11 to 142 TECu) is observed at low and mid-latitudes from
~20o S to 50oS between 2000-0400 UT (1500-2300 LT). The
strong westward penetration electric field suppressed pre-reversal
enhancement, leading to downward plasma drift (~-96 m/s)
at around 2400 UT (1900LT). Overnight, the vertical plasma drift
fluctuated between ±90 m/s owing to under- and over-shielding electric
fields. On May 11, a long-duration (~6-8 hours) westward
penetration electric field induced downward plasma drift and a strong
westward EEJ (-240 nT). In the main and early recovery phase, consistent
short- and long-duration penetration electric fields persisted for
approximately 30 hours, with periods of 48 and 90 minutes.