Space "weather forecast", the danger is known early
Daily life is inseparable from the weather forecast. Astronauts must also pay attention to space weather when they are active in space, rocket launches, and satellite operations. Today, with the rapid development of space exploration, space weather forecasting is becoming more and more important. In the late 1990s, the China Meteorological Administration started space weather operational experiments. In 2002, the National Space Weather Monitoring and Warning Center was established, and in 2004, the space weather business was officially launched. On November 16, 2021, the ICAO Global Space Weather Center was inaugurated to provide space weather services for the global civil aviation industry and ensure aviation safety. Since its establishment in 2002, my country has basically established a space weather monitoring pattern of "integration of heaven and earth". But what is space weather? How to forecast? What are the effects on humans?
what is space weather
Solar eruptions and their resulting changes in the space environment
We, who live on the ground, have become accustomed to the weather changes of cloudy, sunny, rainy and snowy.
But far away from the "Nine Heavens", in the cosmic space that is close to the vacuum, will there also be "weather"?
"Between the earth where we are and the only star in the solar system, the sunlight we can see and feel is actually only a small part of it, a large amount of energy such as gamma and X-rays that are difficult to touch in daily life. Higher light is the frequent visitor." Han Dayang, an engineer at the National Space Weather Monitoring and Warning Center, said that there is also the solar wind that "blows" to every corner of the solar system all the time. They constitute the main body of matter in interplanetary space, which is mainly composed of Composed of charged particles, these particles are very fast, breaking through the gravitational constraints of the sun at a speed of several hundred kilometers per second and entering the universe.
"On the side close to the earth, under the combined action of the sun's rays and the solar wind, energy is changing the space environment of the earth in various forms, from tens of thousands of kilometers away from the ground or even higher. The three-dimensional structure of the Earth's magnetic field, ionosphere, and thermosphere." Han Dayang explained.
On one side is the sun, which is constantly increasing its strengthening level, and on the other side is the earth, which is posing “layers of fronts” to protect the base. The two form an ingenious “tacit understanding” and dynamic “balance” in the cosmic space.
"The sun is not static!" Han Dayang told reporters that the working mode of the sun is generally divided into two categories: calm and explosive. The solar wind released by the sun when it is calm has a low speed, slow change, and relatively low material density. There is no apparent outburst activity.
"Once the explosion mode is turned into, the solar wind will change significantly, speed up, density will increase, and even the temperature will jump up, and the two 'big tricks' of flares and coronal mass ejections will also If it is released at any time, even the cooling time will be greatly shortened, and even the 'Furious Mode' will be turned on, and various explosive activities will occur at the same time or even continuously."
"Corresponding to the two solar activity patterns, the space environment including the Earth's magnetosphere, ionosphere, and thermosphere will also change, and these changes will have serious impacts on artificial satellites and space stations, communication and energy systems, and human health. Harm." Han Dayang concluded that solar eruptions and the changes in the space environment caused by them are called space weather.
Therefore, the "wind" in space weather is the solar wind; the "rain" is the rain of charged particles from the sun.
Where did the term "space weather" come from?
According to Lu Jingtian, an engineer at the National Space Weather Monitoring and Early Warning Center, in 1957, a Science News Letter article in Science News Letter ("Science News") quoted astronomer Lyman Spitzer's research on the interstellar medium, and conducted some of his theories at that time. For explanation, the term "space weather" appears here for the first time.
In 1964, the then director of the U.S. Weather Service proposed at a meeting that a joint group be established in Boulder, Colorado, to study issues related to space weather forecasting.
In 1967, the term space weather appeared in a related technical report of the US Environmental Science Service.
In this way, the term "space weather" has entered the public eye.
By the late 1960s, the term "space weather" had come into widespread use.
what is space weather research
Mainly monitor and study sun related parameters
Just like the meteorological elements such as wind, frost, rain and snow in the earth's weather, there are also environmental parameters that can be detected in the space environment, but they are replaced by parameters such as particles, magnetic fields, and electromagnetic waves.
How is space weather monitoring different from ground-based weather detection?
According to Huang Cong, a researcher at the National Space Weather Monitoring and Early Warning Center, first, the scope is larger, from monitoring the middle and upper atmosphere at a height of 20 to 30 kilometers above the ground to the active area on the surface of the sun; second, the objects are complex, and it is necessary to monitor the middle and upper layers Hydrodynamic parameters such as temperature, density, and velocity in the atmosphere are also monitored, as are plasma parameters such as particles, fields, and temperatures in the ionosphere, magnetosphere, and interplanetary, as well as on the surface of the sun.
"There are also various means of space weather monitoring." Huang Cong said, for electromagnetic waves, optical remote sensing and radio means can be used to observe; for magnetic fields, fluxgate or magnetoresistance technology is used to perceive; for particles, semiconductors or Electrostatic analyzer means to monitor.
What regions are the main concerns of space weather research?
Huang Cong told reporters that it is mainly concentrated in three areas: the source of space weather - the sun, which is about 150 million kilometers from the earth; This area is from the surface of the sun to thousands of kilometers above the ground; the earth response area of space weather - the ionosphere and the middle and upper atmosphere, this area is from thousands of kilometers above the ground to 20-30 kilometers above the ground.
"A complete space weather event generally has the law of formation and occurrence from the surface of the sun, then propagation and evolution in interplanetary space, and finally in the ionosphere and middle and upper atmosphere of the earth." Huang Cong said, therefore, from the For space weather business needs, it is necessary to monitor the important areas on the causal chain of space weather events from the sun-interplanetary-magnetosphere space-ionosphere and upper atmosphere, including the active areas on the surface of the sun. , plasma and electromagnetic parameters such as particles, electric fields, magnetic fields and fluctuations in the interplanetary, magnetosphere and ionosphere, and fluid parameters such as density, temperature and velocity in the thermosphere and ionosphere.
The research object of space weather is the space domain 20 kilometers above the earth's surface, and this is the space domain where most spaceflight, satellite, communication, and navigation activities occur or depend on.
Therefore, severe space weather will have a direct impact on it.
According to reports, for aerospace equipment, the most feared part of the microelectronic components on the spacecraft is the higher energy part of the high-energy particles. These high-energy particles can penetrate electronic components, causing data errors, circuit function confusion or computer integration. The machine is paralyzed, causing the abnormality or failure of the machine, or even destroying it completely.
"And high-energy particles with relatively low energy can generate charge accumulation on the circuit boards, wires and other positions inside the spacecraft, hindering the normal work of the spacecraft." Huang Cong said that during the launch and operation of the spacecraft, the space weather is very important. Continuous monitoring and forecasting of elements and early warning of possible disastrous space weather events can ensure the safety of spacecraft.
How accurate is space weather forecasting?
Entering the digital era, but "just stepped into the threshold"
"The main source of space weather changes is the sun, and violent eruptions of the 'solar atmosphere' will have a significant impact on space weather, such as solar flares, coronal mass ejections, solar proton events, etc." According to Song, senior engineer at the National Space Weather Monitoring and Early Warning Center Qiao introduced that a flare is a phenomenon in which a small area on the surface of the sun suddenly brightens. The radiation enhancement of a flare usually spreads across the entire electromagnetic spectrum, and radiation in high-energy bands such as extreme ultraviolet and X-rays has a particularly significant impact on the Earth's ionosphere.
"The outermost atmosphere of the sun is called the corona, and as the name implies, coronal mass ejections throw massive amounts of magnetized plasma into space, which if they hit Earth, could create geomagnetic storms. And when a solar proton event occurs, , the number of high-energy particles from the sun will increase rapidly, and these high-energy particles will pose a threat to the space station and astronauts." Song Qiao said.
However, we are already prepared for this.
The Fengyun-3E star launched last year carries my country's first space solar telescope, which can observe the activities of the sun's corona, effectively enhance the monitoring capabilities of space weather, and provide data support for more accurate space weather forecasts.
At present, the National Space Weather Monitoring and Early Warning Center has basically realized the "whole process" autonomous observation of the sun-terrestrial causal chain, providing space weather forecasting and impact assessment services for spacecraft launch and on-orbit operations, and providing space for manned space missions. The time window forecast prevents astronauts from encountering severe solar high-energy particle radiation and provides astronauts with a higher safety factor for exiting the cabin.
For example, in 2008, Zhai Zhigang, the commander of the Shenzhou 7 manned spacecraft, became my country's first astronaut to leave space.
At that time, the National Satellite Meteorological Center accurately predicted the time of the exit window in combination with the space weather environment.
How are our space weather forecasts made?
Song Qiao introduced that space weather forecasters will collect the latest observational data, including solar images in various bands, solar X-ray flux, solar magnetic field, geomagnetic index, ionospheric state, etc. Numerical simulation and other forecasts are made, and consultations with the chief forecaster are conducted to draw conclusions on space weather forecasting and produce various forecast products.
"There are many types of space weather forecast products, including daily, weekly, monthly, and annual reports." Song Qiao said that the space weather daily summarizes the space weather conditions in the past 24 hours and forecasts the space weather conditions for the next 1-3 days, including the sun The activity level, geomagnetic activity level, and ionosphere state, etc.; the space weather weekly report summarizes the space weather situation in the last 7 days and forecasts the space weather trend in the next 7 days.
"When important space weather events such as large flares and geomagnetic storms occur, space weather forecasts will also be issued, so that ordinary people can also learn about the latest space weather status."
Today, space weather forecasting has also entered the digital age.
"Based on observational data and scientific theories, methods such as predicting the probability of flare occurrences through physical parameters on the sun's surface and calculating solar wind parameters through numerical models are constantly developing." Song Qiao said that with the launch of exploration spacecraft and satellites in various countries, new There is a steady stream of observational data, and the level of space weather forecasting will steadily improve.
"There is a very interesting phenomenon in solar activity, that is, about every 11 years, there are high solar activity years and low solar activity years. Of course, this can only be said to be a trend, not absolute. And the sun has a long life, We have summed up the 11-year cycle based on limited observations, but with continued observations in the future, the discovered cycle may also change.” According to Guo Jianguang, deputy director of the Space Weather Forecasting Station of the National Space Weather Monitoring and Early Warning Center, space The weather forecast "just stepped on the threshold".
(Our reporter Cui Xingyi)