Is the sun an "e-man" this year? The reason for frequent geomagnetic storms is...

If we use MBTI (personality type) to describe the sun, then this year's sun must be the so-called "E person" (extroverted and active). Now, the geomagnetic storm is "online" again.

According to the official Weibo account of Space Weather, a large geomagnetic storm may occur from last night, October 10th, to the evening of today, the 11th. If no new eruptive activities occur, a small to moderate geomagnetic storm may occur on the 12th, and then gradually return to calm.

For many people, "geomagnetic storm" may still be a new term before this year. However, starting from March 2024, to August and October, geomagnetic storms occurred frequently, with more than 6 recorded events. Geomagnetic storms have even become a "frequent guest" on hot searches, and netizens will actively participate in discussions, attributing "small complaints" in daily life such as sleep problems and emotional problems to the potential impact of geomagnetic storms.

So, do you know what geomagnetic storms are? Why are there so many geomagnetic storms this year? Are the health problems we encounter caused by geomagnetic storms? Let's hear what experts have to say.

Condition of active regions (sunspots) on the solar surface on October 10. Source of Xihe image: Space Weather official microblog

Xu Yuhua, a popular science lecturer at the Zhejiang Astronomical Society, told reporters that the source of the frequent geomagnetic storms is a sign of particularly active solar activity.

"Solar activity follows a cycle of approximately 11 years, and 2024 is at the peak of the 25th solar activity cycle. This means that compared with the past few years, solar activity this year is more frequent and intense, which in turn increases the chance of geomagnetic storms," ​​said Xu Yuhua.

All things grow with the help of sunlight. At the same time, every move of the sun will have an impact on the earth. Xu Yuhua introduced that the atmosphere on the surface of the sun is divided into the photosphere, chromosphere and corona from the inside to the outside. Geomagnetic storms are caused by solar coronal mass ejections.

This ejection is like a "sneeze" from the sun, and the power of this "sneeze" is equivalent to that of a hydrogen bomb explosion. "One ejection can throw hundreds of millions of tons of solar matter away from the surface of the sun at a speed of hundreds to thousands of meters per second. This ejection carries the strong magnetic field energy of the sun. Once it "hit" the earth, the shock wave generated may cause changes in the direction and size of the geomagnetic field, that is, a geomagnetic storm."

"The intensity of this geomagnetic storm will still not bring a particularly big impact." Xu Yuhua explained that solar flares are divided into four levels according to their intensity: B, C, M, and X, with X being the highest level. The strongest solar flare ever recorded occurred in 2003, with an estimated intensity of X45. According to the latest astronomical observation information, the X2.1-level flare that erupted this time did not break the historical record.

The left picture shows the quieter sun during the 11-year solar cycle, and the right picture shows the more active sun. Source: NASA

For ordinary people, the impact of geomagnetic storms is very weak and can be ignored. It will not affect physical health. Xu Yuhua said that there is no need to panic or take special protective measures when encountering geomagnetic storm warnings.

"Geomagnetic storms are a global phenomenon. For aurora enthusiasts or photography experts, this may be a rare opportunity to 'chase the light.'" Xu Yuhua said that geomagnetic storms usually contribute to breathtaking aurora scenes in high-latitude areas. For example, in the past two days, there is a chance that relatively obvious auroras will appear in northern my country, and some areas may even have the possibility of red and green composite auroras.

Compared with ordinary people, geomagnetic storms will have a greater impact on the aerospace field. "One is the impact on the spacecraft itself. High-energy particle flow and geomagnetic disturbances also affect the work of electrical components and flight attitude of space stations and satellites. Astronauts in orbit need to pay attention. In addition, the radiation received by the spacecraft in orbit may be enhanced. Astronauts generally need to avoid extravehicular activities to avoid threats to their health."

As astronomers conduct in-depth research on solar physics, the laws of solar activity have been initially mastered by humans. "We can arrange human activities in advance and effectively avoid the sun's 'little temper' from causing substantial damage to the earth. Researchers are also constantly optimizing space operation strategies to lay the foundation for stable space exploration." Xu Yuhua said.