Will solar storms affect the earth's magnetic field?

Solar wind [1] is a supersonic plasma (charged particles) stream emitted from the upper atmosphere of stars. When it is not the sun, this flow of charged particles is usually called "stellar wind". Solar wind is a continuous plasma flow from the sun, which moves at a speed of 200-800 km/s. Although this substance is different from the air on the earth, it is not composed of gas molecules, but of simpler elementary particles, such as protons and electrons, which are one level smaller than atoms, but the effect they produce when flowing is very similar to that of air flow, so it is called solar wind. Of course, the density of the solar wind is very, very thin and insignificant compared with the density of the wind on the earth. Generally, there are several to dozens of particles per cubic centimeter in interplanetary space near the earth. The density of wind on the earth is 268.7 billion molecules per cubic centimeter. Although the solar wind is thin, it blows more violently than the wind on the earth. On the earth, the wind speed of typhoon 12 is more than 32.5 meters per second, while the wind speed of solar wind is often kept at 350 ~ 450 kilometers per second near the earth, which is tens of thousands of times the wind speed of the earth, and can reach more than 800 kilometers per second at the most violent time. The solar wind is constantly ejected into the stream of material particles in space from the outermost corona of the solar atmosphere. This particle stream is ejected from the coronal hole, and its main components are hydrogen particles and helium particles. There are two kinds of solar wind: one is continuous radiation, which is called "continuous solar wind" because of its low speed and low particle content; The other is radiation when the sun is active, which is fast and has high particle content. This solar wind is called "disturbed solar wind". The disturbed solar wind has a great influence on the earth. When it reaches the earth, it often causes huge magnetic storms and strong auroras, and also produces ionospheric disturbances. The existence of solar wind provides convenience for us to study the sun and the relationship between the sun and the earth.

[Edit this paragraph] Formation reason

In order to clearly express how the solar wind is formed, it is first necessary to understand the stratification of the solar atmosphere.

Generally speaking, we divide the solar atmosphere into six layers, which are named from inside to outside: solar nucleus, radiation belt, troposphere, photosphere, chromosphere and corona layer. The radius of the solar core accounts for about a quarter of the radius of the sun, which concentrates most of the mass of the sun and is where more than 99% of the energy of the sun occurs. The photosphere is the bright round surface of the sun that we usually see, and all the visible light of the sun is emitted by the photosphere.

The corona is located in the outermost layer of the sun and belongs to the outer atmosphere of the sun. It is here that the solar wind is formed and emitted.

In the corona photos taken by X-rays or extreme ultraviolet rays, it can be observed that there are large strips or irregular dark areas in the corona. Through the photos taken by satellites and space probes, we can find that these large dark areas have existed in the corona for a long time. The X-ray intensity here is much lower than other areas, and it looks like some holes in the corona, which is called coronal holes in our image.

Coronal hole is an open area of solar magnetic field, where the magnetic field lines spread into space, and a large number of plasma ran out along the magnetic field lines, forming a high-speed particle flow. The velocity of particle flow at the bottom of the coronal hole is about 16km per second, and it can reach more than 300~400km per second when it reaches the earth orbit. This high-speed plasma flow is what we call the solar wind.

After the solar wind broke out from the coronal hole, it was wrapped in the solar magnetic field and quickly blew around. Now we know that the solar wind can at least blow all over the solar system.

When the solar wind reaches the vicinity of the earth, it interacts with the dipole magnetic field of the earth, blowing back the magnetic lines of the earth's magnetic field. However, the magnetic pressure of the geomagnetic field hinders the movement of the plasma, making it impossible for the solar wind to invade the earth's atmosphere and continue to move around the geomagnetic field. So a cavity is formed, and the geomagnetic field is contained in this cavity. The geomagnetic field looks like an egg with a big head and a small head at this time.

However, when the sun has a sudden violent activity, the situation will change. At this time, the high-energy ions in the solar wind will increase, and these high-energy ions can invade the polar regions of the earth along the magnetic field lines; And discharge in the upper atmosphere of the earth's poles, producing gorgeous and spectacular aurora.

1850, a British astronomer named carrington observed sunspots and found a small flash on the surface of the sun, which lasted about 5 minutes. Carrington thought he happened to see a big meteorite fall on the sun.

[Edit this paragraph] A brief history of observation

In the 1920s, there were more complicated instruments to study the sun. People find that this kind of "sunshine" is a common thing, and its appearance is often related to sunspots. For example, in 1899, American astronomer Hall invented the "solar spectrograph", which can be used to observe the light of a certain wavelength emitted by the sun. In this way, people can take photos of the sun with the help of the light of hydrogen, calcium and other elements in the solar atmosphere. It turns out that the sun's flash has nothing to do with any meteorite, but a brief explosion of hot hydrogen.

Small flash is a very common thing. In places with dense sunspots, as many as 100 times a day can be observed, especially when sunspots "grow". Huge flashes like those seen by Carrington are rare and only happen a few times a year.

Sometimes, the flash happens right in the center of the sun's surface, so it explodes in the direction of the earth. After such an explosion, strange things will appear again and again on the earth. For several days, the aurora will be very strong, sometimes even in temperate regions. The hands of the compass will also be restless and swing wildly, so this effect is sometimes called "magnetic storm". With the progress of science and technology, the mystery of aurora is more and more known to us. It turns out that this beautiful scenery is the work of cooperation between the sun and the atmosphere. Among the forms of energy created by the sun, such as light and heat, one is called "solar wind". The solar wind is charged particles ejected by the sun, and it is a powerful stream of charged subatomic particles, which can cover the earth. The solar wind flows around the earth over the earth and hits the earth's magnetic field at a speed of about 400 kilometers per second. The earth's magnetic field is shaped like a funnel, with its tip facing the north and south poles of the earth, so charged particles emitted by the sun settle along the "funnel" of the earth's magnetic field and enter the polar regions of the earth. The upper atmosphere of the poles, bombarded by the solar wind, will glow and form aurora. What is formed in the Antarctic region is called Antarctic light. What is formed in the North Pole is called the Northern Lights.

Before this century, this situation had no influence on mankind. But in the 20th century, it was found that magnetic storms would affect radio reception, and all kinds of electronic equipment would also be affected. As humans become more and more dependent on these devices, magnetic storms become more and more important. For example, during a magnetic storm, radio and television transmission will be interrupted and radar will not work.

Astronomers studied the sun's flash more carefully and found that hot hydrogen was obviously thrown far away in these bursts, some of which would overcome the great gravity of the sun and shoot into space. The nucleus of hydrogen is proton, so there are proton clouds around the sun (and a few complicated nuclei). 1958, American physicist Parker called this outward proton cloud "solar wind".

When protons flying to the earth reach the earth, most of them will be pushed away by the earth's own magnetic field. However, some will enter the atmosphere, causing aurora and various electrical phenomena. An abnormal explosion when a powerful proton cloud hits the earth will produce a phenomenon that can be called "solar storm". At this time, the magnetic storm effect will appear.

It is also the solar wind that makes comets have tails. When a comet approaches the sun, the dust and gas around the star will be blown back by the solar wind. This effect has also been confirmed on satellites. A large and light satellite like Echo 1 will be blown off the pre-calculated orbit by the solar wind.

[Edit this paragraph] Related impacts

Although the solar wind is fierce, it will not blow to the earth. This is because the earth has its own umbrella-the earth's magnetic field. The geomagnetic field keeps the solar wind out of the earth. However, there will still be a few molecules escaping from the net, although only a few; But it will still bring a series of harm to the earth. It will interfere with the earth's magnetic field and make the intensity of the earth's magnetic field change obviously; It will also affect the upper atmosphere of the earth, destroy the structure of the ionosphere of the earth, make it lose the ability to reflect radio waves without wires, and cause the interruption of our radio communication; It will also affect the chemical changes of the ozone layer in the atmosphere, and transmit it layer by layer until it reaches the earth's surface, causing abnormal changes in the earth's climate, and even further affecting the earth's crust, triggering volcanic eruptions and earthquakes. For example, on July 1959 and 15, people observed that the sun suddenly emitted a huge flame (this is the wind source of the solar wind). A few days later, on July 2 1 day, when this violent solar wind hit the earth's adjacent space, the earth's rotation speed suddenly slowed down by 0.85 milliseconds, and many earthquakes occurred around the world that day; At the same time, the geomagnetic field was violently disturbed by the so-called "magnetic storm", and global communication was suddenly interrupted, making some planes and ships that rely on compasses and radio navigation suddenly become "blind" and "deaf".

The influence of the solar wind on the earth is only caused by the infiltrated molecules. This shows how powerful the solar wind is in the barrier-free interstellar space.

Where the solar wind meets the interstellar matter outside, a shock wave will be generated. The "Voyager 1" probe launched by 1977 is said to have encountered such a shock wave in 2003. That shock wave is about 65.438+0.28 billion kilometers from the sun ~ 65.438+0.8 billion kilometers.

The influence of solar wind on human beings;

1. When the solar wind passes over the earth, it will change the electromagnetic field, cause geomagnetic storms and ionospheric storms, and affect communication, especially short-wave communication.

2. The transmission of strong primary charges to large ground structures such as power grids and pipelines will affect the safety of power transmission, oil transmission and gas transmission pipeline systems.

3. It will also have an impact on satellites in operation.

4. The radiation of solar wind can easily reach one person's X-ray examination. It will also lead to the decline of human immunity, easy to cause pathological changes, easy to make people's mood fluctuate, and even increase car accidents.

It will raise the temperature.

[Edit this paragraph] Scientific research

A house whose windows are blown open by the wind can resist the attack of storms as a whole, but the strong wind that breaks through the window will blow the house into a mess. The latest research shows that the earth's magnetic field is like a house prone to "rain leakage" in front of the solar wind, and its "rain leakage" will last for several hours, providing an opportunity for charged particles from the sun to enter the earth's atmosphere and disrupt communication and power systems.

In the latest issue of the British journal Nature, researchers at the University of California, Berkeley, published the results of this study. The researchers said that the new results will help to better predict the possible impact of bad "space weather" such as solar storms on the earth.

From time to time, the sun blows out a solar wind composed of charged particles. If the solar activity becomes violent, so will the solar wind. The earth itself has a magnetic field extending tens of thousands of kilometers into space, which can form a protective barrier against the solar wind. However, this obstacle is not without defects. As early as 196 1 year, Dr. Deng Gai of Imperial College London, London, England predicted that when the direction of the magnetic field contained in the solar wind is partially opposite to that of the earth's magnetic field, the process of "magnetic reconnection" between the two magnetic fields will lead to a gap in the earth's magnetic field protection barrier, so that charged particles of the solar wind can take advantage of it. Other scientists later confirmed the existence of this gap, but scientists have been unclear whether this gap in the earth's magnetic field is intermittent or will remain open for a long time.

Frey of the University of California, Berkeley, said that he and his colleagues found for the first time that the gap in the earth's magnetic field would open for several hours with the help of NASA's image detector and the observation data of satellites belonging to the European and American "cluster" project. According to their calculations, on the boundary of the Earth's magnetic field barrier, which is about 60,000 kilometers away from the Earth's surface, the gap area may reach twice the earth's area, and the solar wind thus entering will eventually produce a proton aurora equivalent to the size of California in the ionosphere above the North Pole.

[Edit this paragraph] Scientific significance

The discovery of solar wind is one of the important discoveries in space exploration in the 20th century. After nearly 40 years of research, we have a basic understanding of the physical properties of the solar wind, but so far people still don't know how the solar wind originated and how it accelerated. How to obtain plasma and energy supply for solar wind is a basic problem that has not been solved in the field of space physics after long-term research.

[Edit this paragraph] Other related

20 12 at midnight on September 22nd, a colorful light curtain will cover Manhattan, new york, USA. In southern areas like new york, few people can see this extremely fascinating aurora phenomenon. However, people's mood of enjoying the beautiful scenery will not last long. After a few seconds, all the light bulbs in the area began to dim and flicker, and then the light suddenly increased in an instant, and the light bulbs became extremely bright. Then, all the lights went out. In 90 seconds, the whole eastern United States will be blacked out. In a year's time, millions of Americans will begin to die, and the national infrastructure will be in ruins. The World Bank will announce that the United States has become a developing country. At the same time, Europe, China, Japan and other regions or countries are also struggling in this disaster like the United States. This disaster comes from a violent solar storm, which happened on the surface of the sun 65.438+0.5 billion kilometers away from us.

The above story may sound absurd. Under normal circumstances, the sun will not cause such a huge disaster to the earth. However, in a special report released on June 5438+ 10, 2009, the National Academy of Sciences claimed that such a disaster was entirely possible. The research report was funded by NASA. In the past few decades, while human society has developed, it has also laid the groundwork for its own destruction. The modern lifestyle relies too much on all kinds of technology, which inadvertently makes us face a super danger. The plasma emitted from the surface of the sun may destroy our power grid, which will have disastrous consequences. Daniel Becker, the drafter of the special report of the American Academy of Sciences and a space climate expert at the University of Colorado, believes that "we are getting closer and closer to this possible disaster. If humans are not prepared enough for the possible solar storm, this space storm may cut off the power supply, cell phone signals and even water supply system of human society. "

However, some experts have expressed different views that the impact of solar storms is mainly concentrated in outer space, and living on the earth will not be too obviously disturbed by the blocking effect of the earth's magnetic field and atmosphere. Experts say that when the solar storm is active, sunspots are constantly burning and erupting. During this period, a large amount of ultraviolet rays released will suddenly increase the ionosphere concentration over the earth and absorb short-wave energy, thus causing interference to short-wave radio signals. The mobile phones used in people's daily life, including some radios, do not spread signals through the ionosphere, so the general solar storm will not have much impact on the communication on the earth's surface. Theoretically, the general intensity of solar storms is not enough to break through the protection of the earth's atmosphere and magnetic field, posing a fatal threat to the existing species on the earth. But for the solar storm of 20 12, experts worry that it may become an exception.

It may bring great disaster to the earth.

American scientists have warned that the strong solar storm in 20 12 years will bring great disasters to the earth and human beings, and its influence will permeate all aspects of modern society. According to experts who warned, the impact of solar storms on the earth may be "domino-like". Imagine that when the power grid becomes fragile and unstable, industries closely related to power supply will also become victims: refrigeration equipment stops running, and a large number of foods and medicines in the cold storage lose storage conditions and deteriorate; The water pump suddenly stopped running, and the drinking water of the residents in the community became a problem. In addition, due to the interruption of satellite signal, GPS positioning system will become waste. In fact, a similar incident happened as early as 1859, when the sun broke out and the telegraph line burned down. Of course, there are wired and wireless facilities everywhere on the earth now, but these facilities are hard to stand the test of solar storms. Researcher Wang Huaning: "Not alarmist" Researcher Wang Huaning: Beware of the 20 12 solar storm. According to foreign media reports recently, experts from the National Academy of Sciences pointed out that the sun will enter a new round of activities in 20 12. American scientists are worried that human beings are not prepared enough for the possible solar storm, and this space storm may cut off the power supply, cell phone signal and even water supply system of human society, and its influence will penetrate into all aspects of modern society. Attention in this issue: American experts warn that the 20 12 solar storm may seriously affect human beings. These two days, foreign media reported such a news: American experts warned that the solar storm in 20 12 years may seriously affect human beings. The title of ABC News website is "Is Hurricane Katrina-style solar storm brewing"; Fox's headline is "A strong solar storm may bring the United States to a standstill in a few months". So, is this warning alarmist? After all, there have been many so-called "catastrophe predictions", which were later proved to be nonsense and made people laugh. Not alarmist, but this warning is not alarmist, but based on the conclusion of scientific research. The theory of celestial evolution reveals that the sun, as a relatively stable star, has a history of at least 4 billion years. In such a long time, it is impossible to make a detailed textual research on how many violent epidemics have occurred; However, the observation of the sun-like stars in the Milky Way shows that this eruption must be very frequent, sometimes on a very large scale, far exceeding the power of Hurricane Katrina. Hurricanes are only violent movements of the earth's atmosphere, while solar bursts include strong electromagnetic radiation, high-energy particle streams, large-scale coronal mass ejections, and trigger huge shock waves in interplanetary space. These shock waves impact the earth's magnetic field and atmosphere, causing geomagnetic storms and ionospheric storms. We know that every 1 1 year, the sun will usher in a period of frequent explosive activities, and sun-like stars also have periodic activities. In addition, the time when life phenomena appear in the solar system can be considered to be very short compared with the life span of the sun. The evolution of human beings in life phenomena can be considered as an instant. Perhaps the eruption of the sun is one of the important natural factors that gave birth to human beings, and it does not rule out becoming one of the factors of human extinction. The reason is that the intensity of solar burst activity is not enough to break through the protection of the earth's atmosphere and magnetic field, which poses a fatal threat to the existing species on the earth. But this does not mean that solar eruptions are always as "mild" as they are now. Once the solar burst energy exceeds the protective capacity of the earth's magnetic field and atmosphere, it will inevitably cause a strong change in the space environment near the earth. This change will eliminate some species that are not adapted to this change and give birth to species that can adapt to this change. Therefore, on the scale of the evolution of the sun and solar system, solar storms often occur, while humans do not. So my statement may be more "alarmist" than that of my American counterparts. Metabolism is just a universal law in the universe. But what needs to be emphasized is that there is absolutely no need to panic about this now, because in a short time, mankind will not face such a serious survival crisis; Our "alarmism" is also said on a long time scale. The high-tech system on which human beings depend is very sensitive to solar storms. In this report, American experts pointed out that in the event of a particularly serious solar storm, except for satellites and GPS positioning systems, the power transmission network will become very fragile and unstable, or even completely shut down; It may also lead to "traffic paralysis, communication interruption, financial industry collapse and public facilities chaos, interruption of drinking water supply due to pump stop, lack of refrigeration equipment, and difficulty in effectively preserving food and medicine". The report also pointed out that a similar incident occurred as early as 1859 when the sun broke out, which actually led to the burning of telegraph lines. Now the earth is full of wired and wireless facilities, but these facilities can hardly stand the test of strong solar storms. As for the example of the harm caused by solar storms to human beings, the media reported more about the impact of human space activities in the past, but will strong solar storms have a serious and extensive impact on ground facilities and human beings? This is a very interesting question. But from the perspective of the development of human society, it is not difficult to answer. When human beings are still a vulnerable species on the earth, there are few opportunities to be affected by natural disasters, and they are mainly in danger of being wiped out by other species. In fact, hurricanes, earthquakes and tsunamis often occur. Why do they cause a lot of human deaths now? The reason is that human beings have become the only dominant species on the earth, so they are bound to withstand the test of natural disasters. This is also the practical significance of investigating the causes of dinosaur extinction. With the development of science and technology, the scale of high-tech systems established by human beings is getting larger and larger, and the dependence on these systems is getting higher and higher. These systems are more and more sensitive to the changes of the surrounding environment, so the disaster events of technical systems will have more and more influence on human society. At present, the high-tech systems sensitive to solar eruption mainly include: aerospace, communication, navigation, power grid, oil pipeline and other systems. In addition, at a deeper level, solar activities have a comprehensive impact on human society by adjusting the frequency and intensity of natural disasters such as earthquakes, droughts and floods on the earth. How should humans plan ahead? If human beings have foreseen the great harm that strong solar storms may bring, what can we do to reduce losses? First of all, we need to improve our ability to predict solar activity. Judging from the accumulated solar observation data, human beings can effectively predict the long-term change of solar activity and the short-term activity level of the sun. For example, we can predict that the next peak of solar activity will be around 20 12. By observing various phenomena on the sun, such as sunspots, prominence and coronal holes, we can judge the level of solar activity in the next few decades and predict the probability of solar storms. These prediction abilities are of great help to spacecraft launch and flight, astronaut space activities, satellite load reinforcement and protection, communication system anti-interference reinforcement, power system protection and so on. However, realistically speaking, solar activity forecast, especially severe solar activity forecast, is still the most difficult part of space weather forecast. The reason is that we can only indirectly measure many physical parameters in the solar atmosphere by remote sensing, and can only describe the physical state of the solar atmosphere qualitatively, so we can't give a relatively accurate forecast of solar activity. Therefore, for a rainy day, the first thing to do is to study the physical mechanism of intense solar activity and improve our forecasting ability. In addition, people also need to analyze and study the fragile factors of high-tech systems in solar storms, and improve the ability of technical systems to resist solar storms. It is also necessary to strengthen the popularization of solar storms and space weather disasters and raise the awareness of disaster prevention among the whole people. To make the above preparations, it is necessary to increase investment in scientific research and education in related fields. Read more about Science Times (2009-1-16 a1news) American experts warned that the solar storm in 20 12 may seriously affect human beings.