In the face of space weather, we must rely on luck, because it is difficult to predict

It is difficult to predict space weather -only an hour can prevent disasters on the earth.

Dune -like northern light. Essence

The interaction between the solar wind and the atmosphere of the earth produces the northern lights dancing in the night sky.

(Image source: Gram Weipus)

Martin Gerard Connors, Professor

The latest development of astronomy at the forefront allows us to observe the weather that runs around other stars. In fact, we already know that other planets in our solar system also have weather, and in many cases, they are more extreme than ourselves.

Our life is affected by the short -term changes in the earth's weather, and we are worried that long -term climate change will also have a huge impact. The recently created term "space weather" refers to the effect of appearing in space but affecting the Earth and its surrounding areas.

Space and weather are more delicate than meteorological weather, usually acting on the technical system, and have the potential effects of interrupting from communication to the grid failure.

The ability to predict space and weather is an important tool for providing warning so that they can try to reduce the impact and hope to prevent disasters in extreme circumstances.

History of weather forecast

We are now accustomed to conduct quite accurate large -scale meteorological forecast within about two weeks.

The scientific weather forecast originated about a century ago. The term "front line" was related to the First World War. Meteorological forecasting is based on a deep understanding of basic theory, and has been incorporated into a large number of computer programs running on the most advanced computer, and has a large amount of input data.

The important aspects of weather, such as water content, can be measured through continuous monitoring satellites. Other measurements are also easy to carry out, such as launching nearly 2,000 weather balloons per day. The limit of exploring weather forecast caused chaos theory, sometimes called "butterfly effect". The cumulative accumulation brings two weeks of actual restrictions.

In contrast, the prediction of space weather is really reliable only about an hour in advance!

Solar effect

Most space weather comes from the sun. Its outermost atmosphere is blown into space with supersonic speed. Although the density is so low, the planetary space is more rare than the vacuum we think of the laboratory. Unlike the wind on the earth, this solar wind is carried with a magnetic field.

This is much smaller than the Earth's itself we can detect on the surface with a compass on the surface, and it is much smaller than the field near the refrigerator magnet, but it can interact with the earth and play an important role in space weather.

The very thin solar wind, with a very weak magnetic field, can still affect the earth, partly because it interacts with a large magnetic bubble around the earth. It is called a magnetic layer. Planet.

Just like the breeze that can hardly move a line can move a huge sailing boat on the big sail, the influence of the solar wind, through its direct pressure (such as on the sail) or the magnetic field that interacts with the earth, it can be huge of.

As the origin point, the sun itself is a hot gas and magnetic field. Their interaction is complicated, sometimes even explosive. The magnetic field is concentrated near the sun, and the electromagnetic phenomenon is generated, such as the sun's spots (the name explains everything) and the corona material. Just like the tornado on the earth, we usually know when conditions are conducive to these local explosions, but it is difficult to make accurate predictions.

Even if a event is detected, if a large amount of fast, hot, and dense gas is shot in our direction (and such a "cloud" is difficult to detect, the glare of the sun strikes us), there will be a predictive danger to predict its danger Another complex factor of sex.

Detect magnetic field

Different from the very important atmosphere in the meteorology, sometimes the water content that can be detected, sometimes or even visible, the gas magnetic field sprayed from the sun, including the hot and dense clouds generated by the explosion, is almost impossible to detect from a distance. If the magnetic field direction of the planetary cloud is opposite to the direction of the earth's own magnetic field that hit the earth's magnetic layer barrier, the impact of the interstate cloud will be greatly enhanced. In this case, a process called "re -connection" allows most of the energy to move to the area near the earth, and it is mainly accumulated at night, although the cloud will hit the side of the sun.

Through the secondary process, further connection is usually involved, and this energy will produce spatial weather effects. The radiation zone of the earth can be greatly stimulated, endangering astronauts and even satellites. These processes can also produce bright auroras, and their beauty hides danger because they will produce magnetic fields in turn. When the beating aurora changes the magnetic field, the generator effect will be produced, but unlike the generator generated by most of our electricity, the electric field from Aurora is not controlled.

The electric field generated by Aurora is very small, and human senses cannot be detected. However, in a very large area, they can build a considerable voltage. It is this impact that pose a threat to our biggest infrastructure (such as power grids). In order to predict when this happens, we need to measure the size and direction of the magnetic field in the space cloud from a distance. However, the invisible field was hidden and it was difficult to find until it approached us.

Satellite monitor

According to the law of rail gravity, the satellites that directly measure the continuous monitoring magnetic field must be located about 1 million miles (1.6 million kilometers) from the earth, which is a hundred times farther from us and the sun. The magnetic cloud that causes mild space weather usually takes about three days to reach the earth from the sun. The real dangerous cloud from the larger solar explosion may only take a day. Since our monitoring satellites are closer to the earth, we can only know the key magnetic field direction in one hour before the impact. There is not much time to prepare for fragile infrastructure, such as electricity and communication networks and satellites to survive the best. Because the satellite fleet that needs to provide better early warning has not even been on the drawings, we must rely on luck in the face of space weather. The maximum value of the upcoming solar activity -the surface of the sun is in the most active state in a cycle, and it is expected to reach its peak in 2025 -it is expected to be mild, which may be a small comfort.

It may be that Mark Twain said that "it is difficult to make predictions, especially about the future", but it is indeed the case in space weather.

By: Martin Geral

Fy: Li Jinyang

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