Browsing by Author "Condor Patilongo, Percy"
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Item Open Access Ionospheric Disturbances Observed Over the Peruvian Sector During the Mother's Day Storm (G5-Level) on 10–12 May 2024(John Wiley & Sons, 2024-11-14) Singh, Ram; Scipión, Danny; Kuyeng, Karim; Condor Patilongo, Percy; De la Jara, César; Velasquez, Juan Pablo; Flores, Roberto; Ivan, EdwarThis 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 hr and remained consistent at values of ∼95 m/s and 260 nT between 1700 and 1900 UT (1200 and 1400 LT). At the same time, vertical E x B plasma drift uplifted the equatorial ionosphere, producing the dusk-side super plasma fountain and transferring electron density to higher latitudes. A huge increase (∼1,325%) in electron density (from 11 to 142 TECu) is observed at low and mid-latitudes from ∼20°S to 50°S between 2000 and 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 (1900 LT). Overnight, vertical plasma drift fluctuated between ±90 m/s, and the combined effect of penetration and disturbance dynamo electric fields caused a significant increase (∼530 km) in ionospheric virtual height. In the main and early recovery phase, consistent short- and long-duration electric field disturbances persisted for approximately 30 hr, with periods of ∼48 and 90 min.Item Restricted Ionospheric Responses to an Extreme (G5-Level) Geomagnetic Storm Using Multi-Instrument Measurements at the Jicamarca Radio Observatory on 10–11 October 2024(Wiley, 2025-04-5) Singh, Ram; Scipión, Danny; Kuyeng, Karim; Condor Patilongo, Percy; Flores, Roberto; Pacheco, Edgardo; De la Jara, César; Manay, EdwarOn 9 October 2024, a fast-moving coronal mass ejection erupted from the Sun and interacted with Earth on October 10 at around 1530 UT, causing a powerful G5-class geomagnetic storm with a Sym-H index of approximately −341 nT. During the storm's main phase, a strong eastward penetration electric field led to enhancement in Equatorial Electrojet (EEJ), 150 km echoes, E × B vertical plasma drift, and virtual F-region height (h′F) over the equator that sustained over 1.5 hr between 1530 and 1700 UT (1030–1200 LT), with maximum increases of 290 nT, 85 m/s, 60 m/s, and 280 km, respectively. The enhanced E × B vertical plasma drift caused a significant increase (50%–100%) and latitudinal extension (∼23–51°N and 18–57°S magnetic latitudes) of the equatorial ionization anomaly (EIA) on both sides of the magnetic equator. During the pre-reversal enhancement hour at 00:00 UT (19:00 LT), the combined effects of eastward penetration and the background electric field strongly enhanced upward E × B vertical plasma drifts to 98 m/s causing plasma bubbles to reach higher altitudes (∼950–1500 km) over Jicamarca, as recorded by incoherent scatter radar. Ionospheric irregularities extended poleward, reaching up to 42°N and 43°S magnetic latitudes. The eastward disturbance dynamo electric field and disturbed thermospheric neutral winds caused the nighttime development of the EIA as well as the prolonged ionospheric rise at the magnetic equator. Continuous oscillations in the EEJ, 150 km echoes, E x B plasma drift, h′F, and ionospheric plasma density associated with disturbance polar currents are noticed.Item Open Access Multi-process driven unusually large equatorial perturbation electric fields during the April 2023 geomagnetic storm(Frontiers Media, 2024-02-05) Fejer, Bela G.; Laranja, Sophia R.; Condor Patilongo, PercyThe low latitude ionosphere and thermosphere are strongly disturbed during and shortly after geomagnetic storms. We use novel Jicamarca radar measurements, ACE satellite solar wind, and SuperMAG geomagnetic field observations to study the electrodynamic response of the equatorial ionosphere to the 23, 24 April 2023 geomagnetic storm. We also compare our data with results from previous experimental and modeling studies of equatorial storm-time electrodynamics. We show, for the first time, unusually large equatorial vertical and zonal plasma drift (zonal and meridional electric field) perturbations driven simultaneously by multi storm-time electric field mechanisms during both the storm main and recovery phases. These include daytime undershielding and overshielding prompt penetration electric fields driven by solar wind electric fields and dynamic pressure changes, substorms, as well as disturbance dynamo electric fields, which are not well reproduced by current empirical models. Our nighttime measurements, over an extended period of large and slowly decreasing southward IMF Bz, show very large, substorm-driven, vertical and zonal drift fluctuations superposed on large undershield driven upward and westward drifts up to about 01 LT, and the occurrence of equatorial spread F irregularities with very strong spatial and temporal structuring. These nighttime observations cannot be explained by present models of equatorial storm-time electrodynamics.