Ionospheric Response to the Coronal Hole Activity of August 2020: A Global Multi‐Instrumental Overview

Abstract

We have studied the ionospheric response to a coronal hole event of August 2020 using the data from global ionospheric maps, ground magnetometers and parameters from the instruments onboard SWARM and thermosphere, ionosphere, mesosphere energetics and dynamics satellites. The role of different physical drivers, responsible for observed ionospheric disturbance, has been identified. On the storm day (2 August), a steady southward directed interplanetary magnetic field Bz caused the penetration of magnetospheric convection electric field and positive storm effect in daytime sectors. As a result of prompt penetration electric field (PPEF) on 2 August, a polar‐ward expansion of day‐side ionospheric plasma. On 3 August, the signatures of both disturbance dynamo electric field (DDEF) caused by disturbed thermospheric winds and PPEF have been observed. The westward PPEF and eastward disturbance DDEF on the night‐side caused a strong enhancement in ionospheric plasma parameters at the corresponding sectors. The effect of disturbed thermospheric winds and resultant electric field persisted till the end of 7 August. The large decrease in O/N2 ratio at northern mid‐latitudes which is a consequence of the seasonal impact resulted in the negative storm effects at corresponding latitudinal regions. This study has shown that although the storm of August 2020 was a minor one, the associated high speed solar wind streams emanating from a coronal hole resulted in drastic changes in ionospheric parameters including global electron content, in situ electron density and total electron content at the equatorial ionization anomaly and equatorial electric field.

Whole Heliosphere and Planetary Interactions (WHPI): The Big Picture on Solar Cycle Minima

“…The effects of solar wind forcing on a planetary magnetosphere and atmosphere has been most comprehensively observed at the Earth, where both CMEs and SIRs drive geomagnetic storms (Borovsky & Denton, 2006). These in turn lead to enhanced wave activity, auroral and radiation belt particle precipitation (Bingham et al., 2018; Millan & Thorne, 2007), which leads to an increase in ionospheric temperature, plasma density, and ion upflows and outflows (Ogawa et al., 2019; Wang et al., 2011) and also impacts Earth's neutral atmosphere (thermosphere) thermal structure, density and composition (Solomon et al., 2012; Younas et al., 2022, a paper in this collection). When there is a CIR surviving for multiple rotations, the result is periodic forcing of the Earth's space environment and upper atmosphere.…”

“…The level of participation increased with its expanded scope, encompassing Sun to solar wind to planetary magnetospheres and atmospheres. The articles accompanying this introduction (Allen et al, 2023;Badman et al, 2023;Bregou et al, 2022;Gasperini et al, 2023;Hewins et al, 2023;Hudson et al, 2021;Lloveras et al, 2022;Luhmann et al, 2022;Mlynczak et al, 2022;Palmerio et al, 2022;Riley et al, 2022;Varela et al, 2022;Younas et al, 2022) represent the beginnings of analyses that are likely to continue for years to come.…”

Whole Heliosphere and Planetary Interactions (WHPI): The Big Picture on Solar Cycle Minima

“…The level of participation increased with its expanded scope encompassing Sun to solar wind to planetary magnetospheres and atmospheres. The articles accompanying this introduction Riley et al, 2022;Younas et al, 2022;Mlynczak et al, 2022;Badman et al, 2023;Hewins, Gibson, Webb, et al, 2023 under review;Allen et al, 2023 under review) represent the beginnings of analyses that are likely to continue for years to come.…”

Variability of Ionosphere Over Indian Longitudes to a Variety of Space Weather Events During December 2006

“…To analyze the distinct periods of waves and their existence, a spectrum analysis on D iono is performed with continuous wavelet transform using Morlet wavelet for the duration of our investigation (Nava et al., 2016). To extract the D dyn magnetic disturbance we use the method of wavelet + semblance (Younas et al., 2022).…”