Original title: Aurora phenomenon in many places on the mainland, interpretation by experts from the China Meteorological Administration——
What are the effects of geomagnetic storms and solar flares?
Core Reading
Recently, the aurora phenomenon has appeared in many places in the mainland, which has attracted widespread attention. The aurora phenomenon is closely related to geomagnetic storm activity. Why do geomagnetic storms and recent solar flares occur? Does it have an impact on the lives of ordinary people? The reporter interviewed relevant experts to interpret this.
In the past few days, the aurora phenomenon has appeared in Beijing, Inner Mongolia, Heilongjiang, Gansu, Xinjiang and other places in the mainland, causing widespread concern. The occurrence of auroras is closely related to geomagnetic storm activity. At 9 o'clock on May 11, the National Space Weather Monitoring and Warning Center of the China Meteorological Administration issued a red warning for geomagnetic storms. In addition to geomagnetic storms, recent solar flares have erupted many times, which have also caused heated discussions.
What are geomagnetic storms, solar flares? Why do they happen? Does it have an impact on the lives of ordinary people? The reporter interviewed experts from the China Meteorological Administration to interpret the relevant issues that people are concerned about.
The production of auroras and their brilliant colors are related to the occurrence of geomagnetic storms
"If it weren't for the recent auroras, there would have been little attention paid to geomagnetic storms. Geomagnetic storms are neither visible nor perceptible to humans. Han Dayang, a senior engineer at the Space Weather Technology R&D Office of the National Space Weather Monitoring and Warning Center of the China Meteorological Administration, said.
Han Dayang explained that the generation of auroras is related to the occurrence of geomagnetic storms. Geomagnetic storm refers to the phenomenon of violent disturbance of the earth's magnetic field, which is often manifested by rapid changes in the direction and magnitude of the earth's magnetic field. The energy that triggers geomagnetic storms comes from the eruptive activity of the sun. When the Earth's magnetic field "fights" with the sun's high-energy matter, particles in the atmosphere are also absorbing energy, and when these energies that do not belong to it are released, flashes of light occur. Oxygen atoms at an altitude of 400 kilometers produce red light when they release energy, oxygen atoms at an altitude of about 200 kilometers produce green light when they are excited by secondary electrons, and nitrogen molecules at about 100 kilometers produce purple light, thus forming a brilliant and colorful aurora.
Guo Jianguang, director of the Space Weather Forecasting Station of the National Space Weather Monitoring and Warning Center of the China Meteorological Administration, said that there have been many coronal mass ejections recently, resulting in geomagnetic storms. In the next few days, there will be a chance to see the aurora in the northern high latitudes of the mainland, such as Inner Mongolia, Heilongjiang, Xinjiang and other places.
A solar flare is an intense flash of light that occurs in the outer atmosphere of the Sun, and its energy comes from the huge magnetic field energy that accumulates inside the Sun. A typical flare eruption will release many different wavelengths of light, such as gamma rays with extremely short wavelengths and high energy, as well as radio waves with wavelengths of several meters or even longer, and different wavelengths of light will be enhanced by many times, such as the soft X-ray band can be enhanced by 5 orders of magnitude compared with the usual state, and the extreme ultraviolet band can be enhanced by hundreds of times.
"Flares can be observed and photographed through optical equipment, not only on Earth, scientists have moved cameras dedicated to shooting flares to satellites, and monitor them in real time 24 hours a day, regardless of sunrise and sunset." Han Dayang introduced.
Based on solar trends, it is normal for geomagnetic storms and solar flares to occur frequently in the near future
In 2002, the China Meteorological Administration established the National Space Weather Monitoring and Early Warning Center, which has been built for more than 20 years, and now can systematically and accurately forecast and warn important space weather processes such as geomagnetic storms.
According to experts from the National Space Weather Monitoring and Warning Center, there are four levels of geomagnetic storm warning from low to high: blue, yellow, orange and red. As an intense energy eruption on the surface of the sun, solar flares are divided into five levels: A, B, C, M, and X, of which A is the least energetic level and X is the maximum energy level.
Why are geomagnetic storms and solar flares so frequent recently? Is it normal?
Han Dayang explained that it is normal for geomagnetic storms and solar flares to occur frequently in the near future. Statistics show that there have been three geomagnetic storms since May, namely May 3 and May 6, and the geomagnetic storm process that is still continuing from 23 o'clock on May 10. There are even more solar flares, and in just over 10 days since May, there have been more than 10 X-class flares and more than 60 M-class flares.
"Judging from the current trend of solar activity, the possibility of geomagnetic storms and solar flares in the near future is relatively high." Han Dayang said.
It generally has no impact on the lives of ordinary people, does not affect physical health, and does not require special protection
Will geomagnetic storms and solar flares have an impact on our lives? Experts responded that geomagnetic storms and solar flares will only have some impact on high-tech industries such as aviation and communications, and generally have no impact on the lives of ordinary people, nor will they affect their health, let alone special protection.
Experts explain that solar flares are similar to sunlight, except that their energy is many orders of magnitude stronger. "When a flare occurs, the ionosphere wrapped outside the Earth receives much more radiation than usual, and the rapid movement of air particles causes the density and structure of the ionosphere to change, and the radio wave signals that should be reflected back to the ground are affected." The phenomenon of short-wave absorption due to ionospheric disturbance has brought problems such as signal loss and deterioration of communication quality to short-wave communication commonly used in modern aviation, navigation and other fields.
Solar flares do not affect the lives of ordinary people, though. Under the protection of the atmosphere, the radiation of the flare is greatly reduced in all bands, and the part that reaches the ground is very small. At the same time, modern technology has ways to deal with the problem of radio communication deterioration caused by flares, such as adjusting the communication frequency and changing the communication method.
When a geomagnetic storm occurs, the atmosphere in high latitudes is heated and expands under the action of Joule heating and high-energy particle deposition, and transmits this change to the world with the atmospheric circulation, causing the density of the upper atmosphere to rise, creating greater flight resistance for artificial spacecraft operating at orbital altitudes below 500 kilometers, and causing obvious attenuation of their orbits, which is called atmospheric drag in spaceflight. Another type of effect is that the occurrence of geomagnetic storms causes changes in geomagnetic information, making pigeons easy to get lost during the flight, resulting in the loss of carrier pigeons.
For the average person, the impact of geomagnetic storms is very weak and completely negligible. Regarding the impact of space weather activities on some industries, the National Space Weather Monitoring and Warning Center of the China Meteorological Administration has been working closely with relevant industry departments for a long time to discuss countermeasures and mitigation strategies for different technical systems.