Geomagnetic storms are on the hot search again and again, due to the recent outbreak of several X-class strong flares in the sun. According to the National Space Weather Monitoring and Warning Center, the National Space Weather Monitoring and Warning Center issued a red warning for geomagnetic storms at 9 o'clock on May 11: geomagnetic storms will occur from 23 o'clock on May 10, 2024, Beijing time, and the maximum level will reach the level of super geomagnetic storms (Kp=9), and it is expected that the magnetic storm process will continue in the next 24 hours, and geomagnetic storms may still occur in the future.
Through the sentiment analysis of the Weibo platform, nearly 6 percent of the audience's sentiment in related searches is "fear". Concerns include, but are not limited to: geomagnetic storms may cause headaches, inability to sleep, inability to get out of bed, not wanting to go to work, dizziness and nausea, poor mood, and sleepiness......
Don't panic or be afraid, let's find out, what is a geomagnetic storm?
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Frequent hot searches! What is a "geomagnetic storm"?
A geomagnetic storm is a typical type of solar eruptive activity. When the Sun erupts, coronal mass ejections occur, and a single ejection can throw hundreds of millions of tons of solar material off the surface of the Sun at high speeds of hundreds to thousands of meters per second.
This stream of high-energy charged particles from the Sun originates mainly from the outermost layer of the Sun's atmosphere, the corona. The coronal layer is extremely hot and the matter is extremely thin, and the matter exists in the form of charged plasma. Normally, these charged particles are trapped in the enclosed solar magnetic field and are difficult to escape on a large scale, but in two types of cases, they will eject smoothly:
First, there is a specific structure of the corona that is relatively stable (lasting for several days), such as a coronal hole with a lower temperature and relatively open magnetic field lines, where the flow of charged particles will successfully escape the constraints of the solar magnetic field and form a high-speed flow of the coronal hole.
Even more dramatic are anomalous magnetic disturbances caused by intense solar activity (including but not limited to flare eruptions), resulting in local openings of magnetic field lines, where these "magnetic gaps" are more likely to erupt rapidly and form coronal mass ejection (CME) events, which tend to trigger more significant magnetic storms.
When the flow of high-energy particles corresponding to CME enters the range of the earth's magnetic field, the geomagnetic field will be compressed and deformed, and a large number of charged particles will be injected into the magnetosphere region, causing a sharp change in the current of the magnetospheric ring. Since the changing current will produce a changing magnetic field, this part of the charged particle flow will add an additional part of the induced magnetic field to the geomagnetic field, which is called geomagnetic disturbance, and the stronger part will be called geomagnetic storm.
Multiple total halo CME (SOHO satellite observations) observed on May 8-9 Source: National Space Science Center, Chinese Academy of Sciences
The intensity of geomagnetic storms is mainly classified according to a specific geomagnetic index. These indices reflect the intensity of geomagnetic activity, which helps us understand the intensity level of geomagnetic storms.
Specifically, commonly used geomagnetic indices include the Dst index and the Kp index. The DST index, or Geomagnetic Disturbance Index, is an important indicator for measuring space weather conditions, which reflects the intensity of geomagnetic storms by measuring changes in the horizontal component of the Earth's magnetic field. The Kp index, or Global Magnetic Field Index, reflects the Earth's magnetic field activity every three hours, and the higher the value, the stronger the corresponding geomagnetic activity.
According to the change of the Dst index, the intensity of geomagnetic storms can be divided into five levels: small magnetic storms, medium magnetic storms, large magnetic storms, very large magnetic storms, and very large magnetic storms. At the same time, the Kp index is also used to classify the intensity of geomagnetic storms. According to the change of the Kp index, the geomagnetic activity can be divided into different grades such as calm, uncalm, active, small, large, and intense.
The study found that about every 11 years, solar activity never stops moving from peak to trough and back again. And in each cycle, the Sun erupts several strong solar storms, followed by super flares and dozens of strong geomagnetic storms.
According to the statistics of the National Satellite Meteorological Center (National Space Weather Monitoring and Warning Center), 12 geomagnetic storms have occurred since February, 11 of which are related to solar activity. Recently, there have been continuous solar eruptions, mainly solar flare activity, of which on the afternoon of May 3-7, there were 22 intermediate flares with M intensity and 4 large flares with X intensity.
This is also the reason why there have been frequent hot searches on "geomagnetic storms" since the beginning of this year. "Another reason is that in recent years, the continental air-space integrated monitoring station network has been continuously improved, the space weather monitoring, forecasting and early warning capabilities have been continuously improved, the prediction and forecasting of space weather events have become more accurate and refined, and the monitoring products have significantly contributed to aurora observation, and the public's awareness and attention to space weather events are increasing day by day." Zong Weiguo, director of the Space Weather Technology Research and Development Office of the National Space Weather Monitoring and Warning Center, once explained this.
Large flare of magnitude X3.9 on May 10 (SDO satellite monitoring, UTC). Source: National Space Science Center, Chinese Academy of Sciences
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The famous by-product of geomagnetic storms is the aurora
Some netizens said, "You can chase the aurora", that's right, the aurora is actually the performance of the visualization of geomagnetic storms. Auroras are a natural phenomenon visible to the naked eye on the ground and produced by the interaction of the solar wind with the magnetosphere. Under the combined action of the earth's magnetic field and atmosphere, an aurora feast arrived as scheduled, and gorgeous auroras appeared in Mohe in Heilongjiang and parts of Xinjiang.
How do the aurora occur?
After the coronal material carries the energy of the sun and meets the earth, part of it will enter the poles with the earth's magnetic field and collide with the atmosphere at a height of 100 to 400 kilometers above the ground.
When a solar storm hits the Earth's magnetic field, the magnetosphere is also deformed, and some charged particles enter the atmosphere through the magnetic fields of the Earth's poles, triggering brilliant auroras. Source: China Science Expo
Since the current magnetic poles are also located near the north and south poles geographically, this type of luminescence is concentrated in high latitudes (especially in the higher regions of the "magnetic latitude" that surrounds the magnetic poles, which are also called aurora belts), hence the name aurora auroras.
The colorful colors of the aurora are related to different atmospheric particles and luminescence processes, and are also at different heights.
For example, the most common green aurora is the light emitted when the oxygen atom is excited to the excited state and returns to the ground state in a short time (within 1 second to several seconds), usually at a height of 100~200 kilometers; The red aurora is also the luminescence after the recovery of excited oxygen atoms, but this process takes a long time (tens of seconds to more than 100 seconds), during which once it collides with other particles, it will lose this part of the energy and cannot emit light, so the red aurora is relatively common (about 200~350 km) at the level of lower particle density and higher height.
Generally speaking, due to the thinner luminescent particles at high altitude, the intensity of the red aurora is weaker than that of the green aurora, but because the aurora belt is hundreds of kilometers or even farther north of the continent, the height angle of the aurora that can be seen in the north of the continent is low, and the radian and terrain of the earth's surface are occluded, so for the middle latitudes such as the north of the continent, the red aurora with higher altitude and relatively weak intensity is easier to see.
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Don't want to go to work, is it related to geomagnetic storms?
Geomagnetic storms may have a direct and definite impact on the organisms living on the earth, such as carrier pigeons, that need to be navigated by geomagnetism.
For human society, geomagnetic storms can cause power system disruption or equipment damage, causing additional radiation effects on spacecraft; It may also have an impact on the operation of satellites and space stations, as they need to work in a stable Earth-magnetic environment. Geomagnetic storms can also affect electromagnetic components in electronics and communication equipment, which can lead to problems such as communication disruptions and navigation failures.
Although some studies believe that solar activity and accompanying geomagnetic disturbances have a certain correlation with human blood pressure fluctuations, there is still no direct and clear further study of this correlation. For the larger population, there is currently insufficient evidence to show the impact of geomagnetic storms on physical condition.
"The occurrence of geomagnetic storms has little impact on the daily life of the public, and will have a certain impact on the orbit of aircraft and satellites, but they are also measurable and controllable." The suzerains said that due to the impact of geomagnetic storms on the magnetic field, satellites and space stations may have their orbital altitudes reduced due to atmospheric dragging, and it is necessary to strengthen the monitoring of orbits and adjust orbits as needed. The positioning error of satellite navigation equipment may increase, but it has little impact on the daily use of navigation and other functions by the public.
For aviation flights, the radiation dose for a daily domestic flight is about 2 to 6 microsieverts, and for international flights across the polar regions, the radiation dose is slightly higher, about 50 microsieverts, which is a few hundred to tenths of the national security standard. When a geomagnetic storm or solar proton event occurs, the radiation dose from the air will increase, but the impact of a single flight will not be large, so you don't have to worry. For pigeon release, geomagnetic storm forecast and early warning has a good guiding role in carrying out related activities, and relevant space weather forecast and early warning products can be paid attention to in advance to minimize the release activities under adverse weather conditions and long distances.
Source: Lookout Think Tank Synthesized from WeChat public accounts "China Meteorology", "China Weather Network", "National Space Science Center", "Beijing Daily" and "Popular Science China".