Editor's note:
In May, geomagnetic storms broke out frequently and broke records repeatedly! Aurora has repeatedly appeared on hot searches. In the previous article "When You Look at the Aurora, We Are Looking at the Sun", we described the source and destination of the energy of the solar eruption, and introduced the "sky" in the joint observation of "space-earth integration". Today, we invite the National Space Science Center of the Chinese Academy of Sciences to lead you to understand why the sun frequently erupts and how to monitor the sun's activity on the ground.
01
Outbreak week 25 maximum magnitude flare
The aforementioned AR3664 is a huge sunspot group on the surface of the Sun, spanning approximately 15 Earths from east to west. Some scientists have compared it with the sunspots in the Super Carrington solar storm, which ranks No. 1 in history, and it is not inferior in any way, which is enough to go down in history.
Figure 1. AR3664 vs. Carrington Sunspots and Earth (Ref. spaceweather.com)
Figure 2. Evolution of AR3664 on the surface of the sun
From May 8th to the present, the sunspot activity area AR3664 has not been idle for a moment since it appeared on the sun, and more than 10 large flares have erupted one after another, and on May 14th, in fact, AR3664 has "left" the visible sun, and the largest X8.7 large flare since September 2017 has erupted, setting a new flare intensity record since the 25th week.
Figure 3. A large X-class flare that erupted in AR3664 on May 8-14, 2024
Figure 4. AR3664 has been turned out of the visible solar surface with an X8.7 flare
It is worth noting that the magnetic storm has nothing to do with X8.7 flares, but they are all masterpieces of AR3664.
Since May 10, multiple total halo coronal mass ejections (CME) eruptions in the active area AR3664 have reached the Earth one after another, triggering strong geomagnetic disturbances and extremely geomagnetic storm events.
A total of 18 hours reached the level of a very strong geomagnetic storm (Kp=9), the strongest level of magnetic storm seen in the last 20 years, reaching the red alert level, which really shocked forecasters (Figure 6).
Figure 5. Eruptions from 8 to 11 Multiple Eruptions of Sun Surface Material Ejections (CME)
▲Figure 6. The geomagnetic K index inverted from the monitoring data of the autonomous geomagnetic station of the project at noon on May 10-14
02
Tracking Solar Storm "Weapon"
The Space Environment Prediction Center of the Chinese Academy of Sciences has carried out early warning and observation of the super geomagnetic storm that occurs once in 20 years, and the relevant facilities and the independent forecasting model of the Chinese Academy of Sciences have strongly supported the early warning and service guarantee for major national tasks.
These are the "sharp tools" that we use to track solar storms.
Space-ground equipment jointly "keeps an eye on" the solar storm
As the only major national scientific and technological infrastructure in the field of space weather on the mainland, the ground-based comprehensive solar exploration satellite "Kuafu-1" serves as the "eye of the sky", and the ground-based comprehensive monitoring meridian chain of the space environment in the eastern hemisphere is the only major national scientific and technological infrastructure in the field of space weather so far.
Figure 7. Observation map of the flare eruption of AR3664 in the sunspot activity area (left, provided by the team of the Purple Mountain Astronomical Observatory of the Chinese Academy of Sciences for "Kuafu-1" (ASO-S); Right, courtesy of Huairou Solar Observatory, National Astronomical Observatories, Chinese Academy of Sciences)
The whole chain of sun and earth accurately predicts the space environment
With the support of the key scientific research projects of the Chinese Academy of Sciences, the Space Environment Prediction Center has built the first solar-terrestrial full-chain space weather numerical prediction technology platform in mainland China, which has realized the numerical prediction of key space environment elements from solar eruptions, interplanetary propagation, to near-Earth influences, and provided a solid foundation for the accurate prediction of recent frequent solar storms.
Figure 8. Simulation of the propagation process of two CMEs over the 2AU range of the ecliptic plane on May 8 and 9
Prediction and early warning, effective
As the operating agency of the China Regional Alert Center of the International Space Environment Service Organization, the Space Environmental Forecasting Center of the Chinese Academy of Sciences has been monitoring the development of the event with space-based monitoring data since the beginning of this incident, and has sent early warning information products to space stations and other users as soon as possible.
In response to the megamagnetic storm event, the forecast center began to issue a strong geomagnetic storm warning on May 8, and on the evening of the 10th, it again released early warning information to users of the manned space station, space science pilot projects, and the public.
The forecast center used the data of the "Orbital Atmospheric Density Detection Test Satellite (referred to as Spherical Star)" jointly developed by the Key Laboratory of Solar Activity and Space Weather of the National Space Science Center of the Chinese Academy of Sciences and the Shanghai Institute of Microsatellite Innovation to analyze the impact of magnetic storms, the daily attenuation rate before the magnetic storm was 110 m/day, and during the magnetic storm, the daily attenuation rate was up to 542 m/day, an increase of about 4 times, and the magnetic storm had a significant drag attenuation effect on the satellite.
03
The "gift" of geomagnetic storms
Geomagnetic storms of this magnitude have brought beautiful aurora borealises, which have triggered rounds of public attention.
Nowadays, although the AR3664 activity area is gone, the current solar activity is still in the peak year of the 25th activity week, and a number of new activity areas have emerged, and the new activity area that is still on the eastern edge of the solar surface and has not yet been given an "identity number" has successfully taken over, and as soon as it emerged, a large X2.9 flare broke out.
In the coming period, solar eruptions will be particularly frequent, and the research and monitoring of the sun will continue, so please continue to pay attention to the research results of the Chinese Academy of Sciences.
Figure 10. A large X2.9 flare on the eastern edge of the Sun observed by SDO on the 15th erupted
References:
http://www.sepc.ac.cn
Author: Miao Juan, Luo Bingxian, Zhong Qiuzhen, etc
Source: National Space Science Center, Chinese Academy of Sciences
Editor in charge: Song Tongzhou