On the mutual relationship of the equatorial electrojet, TEC and scintillation in the Peruvian sector

Abstract

This paper presents the interrelationship between the equatorial electrojet (EEJ) strength, Global Positioning System (GPS)‐derived total electron content (TEC), and postsunset scintillation from ground observations with the aim of finding reliable precursors of the occurrence of ionospheric irregularities. Mutual relationship studies provide a possible route to predict the occurrence of TEC fluctuation and scintillation in the ionosphere during the late afternoon and night respectively based on daytime measurement of the equatorial ionosphere. Data from ground based observations in the low latitudes of the west American longitude sector were examined during the 2008 solar minimum. We find a strong relationship exists between the noontime equatorial electrojet and GPS‐derived TEC distributions during the afternoon mediated by vertical E × B drift via the fountain effect, but there is little or no relationship with postsunset ionospheric scintillation.

Effects of Electric Field and Neutral Wind on the Asymmetry of Equatorial Ionization Anomaly

“…The strength of EIA asymmetry is calculated by taking the ratio of the maximum value of the two hemispheric anomaly TEC crests values. Besides the meridional neutral winds, dragging force due to continuous ion accumulation, sudden stratospheric warming, solar fluxes, atmospheric tides, change in composition due to magnetic perturbations, and photochemical process are also responsible factors for the asymmetry of the EIA peaks (Abdu et al, , ; Dang et al, ; Goncharenko et al, ; Hanson & Moffett, ; Immel et al, ; Jonah et al, ; Khadka et al, ; Tulasi Ram et al, ; Xiong et al, ). In this study, we particularly focused on analyzing the contribution of meridional neutral wind for the asymmetry generation of EIA using observational and modeled winds in the low‐latitude ionosphere.…”

“…5.2°S, 279.4°E, 6.8°N dip latitude) in the American low latitudes. As described in Khadka et al (), magnetometer readings of H from each station are normalized with its midnight average background values for each day and subtracted to get only the electrojet contribution to H. The difference of electrojet effect on H between two magnetometers located at equator and off‐equator (6° to 9° away) is defined as the EEJ strength.…”

“…and photochemical process are also responsible factors for the asymmetry of the EIA peaks (Abdu et al, 1990(Abdu et al, , 2008Dang et al, 2016;Goncharenko et al, 2010;Hanson & Moffett, 1966;Immel et al, 2006;Jonah et al, 2015;Khadka et al, 2016;Tulasi Ram et al, 2009;Xiong et al, 2013). In this study, we particularly focused on analyzing the contribution of meridional neutral wind for the asymmetry generation of EIA using observational and modeled winds in the low-latitude ionosphere.…”

Global Positioning System Observations of Ionospheric Total Electron Content Variations During the 15th January 2010 and 21st June 2020 Solar Eclipse

“…During intense geomagnetic storms, a plausible and useful theory behind the dramatic increase in ionospheric electron density and total electron content is the immediate consequence of prompt penetration electric fields (PPEF), that generally tend to arise during the main phase of the storm, and may keep going for a few hours (Khadka et al., 2016). PPEF penetrating from high latitudes to the equatorial region create an ionospheric “superfountain” that vertically advects plasma from low to mid‐latitudes through E × B drift (Chapagain et al., 2012; Khadka et al., 2016).…”

Climatology of Ionospheric Amplitude Scintillation on GNSS Signals at South American Sector During Solar Cycle 24

“…Several works have investigated the ionospheric scintillation at the SA sector at some periods of solar cycle 24, which has just ended (e.g., De Rezende et al, 2010;Sreeja et al, 2011;Bougard et al, 2013;Alfonsi et al, 2013;Spogli et al, 2013aSpogli et al, , 2013bCesaroni et al, 2015, Khadka et al, 2016Muella et al, 2017;Correia et al, 2018;Guo et al, 2019;De Paula et al, 2019;Oliveira et al, 2020). Some of these works are worthwhile to highlight.…”