Astronomy Research Team: “Strong Solar Wind Collision → Changes in Earth’s Magnetosphere”
What happens when the Sun affects the Earth’s magnetosphere? Severe changes in Earth’s magnetosphere and ionosphere caused by solar storms can severely impact advanced technology. This includes damage to satellites, satellite malfunctions, orbit shifts, interference with satellite or ground-based communication, an increase in GPS errors, and damage to ground power grids, leading to significant socio-economic damage for humanity. It also poses a major risk to space activities, affecting the safety of airline crew and passengers on polar routes and astronauts.
Understanding and predicting this space weather in advance is crucial. It’s important to observe, monitor, understand, and predict changes in solar activity and the space weather in the cosmos.
This year marks the peak of the 11-year solar activity cycle. During the solar maximum, the Sun’s magnetic field strengthens, and sunspot activity becomes more intense. The Korea Astronomy and Space Science Institute’s Solar and Space Environment Group released an analysis of the solar geomagnetic storms that occurred strongly last year.
Geomagnetic storms refer to disturbances in Earth’s magnetic field caused by strong solar storms from the Sun reaching Earth. The severity of geomagnetic storms is rated by the Space Weather Prediction Center (SWPC) of the National Oceanic and Atmospheric Administration (NOAA), ranging from G1 (minor) to G5 (extreme).
In May of last year, the most powerful G5 geomagnetic storm in 21 years occurred. On January 1 of this year, a G4 geomagnetic storm took place.
Using the latest domestic and international satellites and ground observation systems, the Korea Astronomy and Space Science Institute observed the G5 geomagnetic storm from May 10 to 12 last year, comprehensively analyzing its causes and physical mechanisms.
The storm was found to be caused by X-class flares and multiple coronal mass ejections (CMEs) originating from the complex magnetic field configurations of solar activity regions 13664 and 13668. The intensity of solar flares is categorized as A, B, C, M, and X, with X being the strongest.
The X2.2 class flare on May 9 last year triggered a major CME that combined with previous CMEs, resulting in a strong solar wind reaching Earth’s orbit. This compressed Earth’s magnetosphere significantly, causing strong magnetic reconnection between the interplanetary magnetic fields heading south and Earth’s magnetic fields.
As a result, energy influx into Earth’s upper atmosphere at high latitudes increased, heating the thermosphere, and altering electron density in the ionosphere. The research team confirmed the occurrence of auroras using all-sky cameras at Jang Bogo Station in Antarctica and Bohyeonsan Optical Astronomy Observatory in Yeongcheon. Neutron monitors installed at Mt. Gamak in Geochang also confirmed changes in space radiation influx.
Researcher Young-sil Kwak of the institute stated, “Through comprehensive analysis of the G5 geomagnetic storm, we have gained a better understanding of the Sun and Earth’s magnetosphere interaction, global impacts, and mechanisms. This will help us understand space weather changes this year during the solar maximum and serve as a good basis for future precautions.”
The institute is hosting Solar and Space Environment workshops and winter schools in collaboration with the Korean Space Science Society and the Korean Astronomical Society. From January 13 to 15, over 100 domestic space weather researchers will gather at the institute to present the latest trends.