Equatorial Plasma Bubbles Observed at Dawn and After Sunrise Over South America During the 2015 St. Patrick's Day Storm

Author(s)

Carmo, C. S. ; Pi, X. ; Denardini, C. M. ; Figueiredo, C. A. O. B. ; Verkhoglyadova, O. P. ; Picanco, G. A. S.

• Document type: Journal article
• Source: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS; v. 127, n. 10, p. 16-pg., 2022-10-01.

Abstract

This paper presents an analysis of Equatorial Plasma Bubble (EPB) events that occurred during pre- and post-sunrise hours in the South America sector on 18 March 2015, when the St. Patrick's Day geomagnetic storm was in the recovery phase. The data from a set of multi-diagnostic instruments, including Global Navigation Satellite Systems (GNSS) receivers, L-band GNSS ionospheric scintillation monitors, ionosondes, and a Fabry-Perot interferometer, are analyzed. Strong L-band amplitude scintillation was observed with spread-F and total electron content (TEC) fluctuations at times when the electron density and tTEC were minimum with respect to their diurnal variations. The EPBs remained observed for about 3:30 hr after sunrise on the east coast of the South American continent. The daytime ionospheric irregularities show a longitudinal dependency between the west and east coasts, separated by about 3,600 km. Our analysis of the observations suggests that a Disturbance Dynamo Electric Field effect caused by storm-time wind perturbations might have triggered the Rayleigh-Taylor instability near local dawn on the east and west coasts of the South American continent. The effects of ambient ionosphere-thermosphere conditions on the evolution of irregularities are assessed to understand the longitudinal differences. The assessment includes the effect of the E region that appears in the morning hours and the effects of geomagnetic declination and tilting the solar-terminator. (AU)

• FAPESP's process: 19/22548-4 - Sources of traveling ionospheric disturbances over the Andes mountains
• Grantee: Cosme Alexandre Oliveira Barros Figueiredo
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 18/09066-8 - TRAVELLING IONOSPHERIC DISTURBANCES OBSERVED BY DETRENDED TOTAL ELECTRON CONTENT MAPS/KEOGRAM OVER ANDES MOUNTAINS
• Grantee: Cosme Alexandre Oliveira Barros Figueiredo
• Support Opportunities: Scholarships in Brazil - Post-Doctoral