Bibliography

Interhemispheric Asymmetries in Ionospheric Electron Density Responses During Geomagnetic Storms: A Study Using Space-Based and Ground-Based GNSS and AMPERE Observations

We utilize Total Electron Content (TEC) measurements and electron density (Ne) retrieval profiles from Global Navigation Satellite System (GNSS) receivers onboard multiple Low Earth Orbit (LEO) satellites to characterize large-scale ionosphere-thermosphere system responses during geomagnetic storms. We also analyze TEC measurements from GNSS receivers in a worldwide ground-based network. Measurements from four storms during June and July 2012 (boreal summer months), December 2015 (austral summer month), and March 2015 (equinoctial month) are analyzed to study global ionospheric responses and the interhemispheric asymmetry of these responses. We find that the space-based and ground-based TECs and their responses are consistent in all four geomagnetic storms. The global 3D view from GNSS-Radio Occultation (RO) Ne observations captures enhancements and the uplifting of Ne structures at high latitudes during the initial and main phases. Subsequently, Ne depletion occurs at high latitudes and starts progressing into midlatitude and low latitude as the storm reaches its recovery phase. A clear time lag is evident in the storm-induced Ne perturbations at high latitudes between the summer and winter hemispheres. The interhemispheric asymmetry in TEC and Ne appears to be consistent with the magnitudes of the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) high latitude integrated field-aligned currents (FACs), which are 3–4 MA higher in the summer hemisphere than in the winter hemisphere during these storms. The ionospheric TEC and Ne responses combined with the AMPERE-observed FACs indicate that summer preconditioning in the ionosphere-thermosphere system plays a key role in the interhemispheric asymmetric storm responses.

Swarnalingam, N.; Wu, D.; Gopalswamy, N.;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2022     DOI: 10.1029/2021JA030247

Short-term variability of the Sun-Earth system: an overview of progress made during the CAWSES-II period

This paper presents an overview of results obtained during the CAWSES-II period on the short-term variability of the Sun and how it affects the near-Earth space environment. CAWSES-II was planned to examine the behavior of the solar-terrestrial system as the solar activity climbed to its maximum phase in solar cycle 24. After a deep minimum following cycle 23, the Sun climbed to a very weak maximum in terms of the sunspot number in cycle 24 (MiniMax24), so many of the results presented here refer to this weak activity in comparison with cycle 23. The short-term variability that has immediate consequence to Earth and geospace manifests as solar eruptions from closed-field regions and high-speed streams from coronal holes.

Gopalswamy, Nat; Tsurutani, Bruce; Yan, Yihua;

Published by: Progress in Earth and Planetary Science      Published on:

YEAR: 2015     DOI: 10.1186/s40645-015-0043-8

Large Geomagnetic Storms: Introduction to Special Section

Gopalswamy, N;

Published by:       Published on:

YEAR: 2010     DOI:

Introduction to special section on Large Geomagnetic Storms

Gopalswamy, N;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2009     DOI:

A Sun-to-Earth Campaign Joining Observations from the Great Observatory with Worldwide Satellite and Ground-Based Resources to Investigate System Science Frontiers

Kozyra, JU; Shibata, K; Barnes, RJ; Basu, S; Davila, JM; Fox, NJ; Gopalswamy, N; Kuznetsova, MM; Pallamraju, D; Paxton, LJ; , others;

Published by:       Published on:

YEAR: 2006     DOI:

Investigating the state of the Sun-Earth system during extreme events: First science results of a worldwide online conference series

Kozyra, JU; Shibata, K; Fox, NJ; Basu, S; Coster, AJ; Davila, JM; Gopalswamy, N; Liou, K; Lu, G; Mann, IR; , others;

Published by:       Published on:

YEAR: 2006     DOI:

Introduction to violent Sun-Earth connection events of October\textendashNovember 2003

The solar-terrestrial events of late October and early November 2003, popularly referred to as the Halloween storms, represent the best observed cases of extreme space weather activity observed to date and have generated research covering multiple aspects of solar eruptions and their space weather effects. In the following article, which serves as an abstract for this collective research, we present highlights taken from 61 of the 74 papers from the Journal of Geophysical Research, Geophysical Research Letters, and Space Weather which are linked under this special issue. (An overview of the 13 associated papers published in Geophysics Research Letters is given in the work of Gopalswamy et al. (2005a)).

Gopalswamy, N.; Barbieri, L.; Cliver, E.; Lu, G.; Plunkett, S.; Skoug, R.;

Published by: Journal of Geophysical Research      Published on: 09/2005

YEAR: 2005     DOI: 10.1029/2005JA011268

coronal mass ejections; Geomagnetic storms; interplanetary shocks; solar energetic particles; Solar flares; superstorms

Introduction to violent Sun-Earth connection events of October—November 2003

Gopalswamy, N; Barbieri, L; Cliver, EW; Lu, G; Plunkett, SP; Skoug, RM;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2005     DOI: