What is space weather? Astronauts must look at it before they leave the cabin and before the carrier pigeons are released

People living on the ground should pay attention to meteorological weather forecasts, and astronauts should pay attention to space weather when they are active in space.

"Less than one in ten thousand people know the meaning of the four words space weather." The China Meteorological Administration's National Space Weather Monitoring and Early Warning Center's information release platform reads such a sentence.

In the late 1990s, the China Meteorological Administration began experimenting with space weather operations. In 2002, the "National Space Weather Monitoring and Early Warning Center" was established, and in 2004, the space weather business was officially launched. On November 16 this year, the Global Space Weather Center of the Sino-Russian Consortium was inaugurated, which will realize real-time monitoring and identification of global space weather, information display and disastrous space weather warning, and enhance the international influence of China's space weather aviation services.

What is space weather? How to forecast? What impact does it have on human life? The reporter interviewed Guo Jianguang, deputy director of the Space Weather Room of the National Satellite Meteorological Center (National Space Weather Monitoring and Early Warning Center), to answer the above questions.

Astronauts should refer to the space weather forecast when leaving the capsule

Beijing News: What is space weather? What is the role of the Global Space Weather Center?

Guo Jianguang: In layman's terms, space weather refers to the state or event in the solar space that can affect the ground advanced technical system or endanger human health, mainly caused by solar activity. Space weather forecasting is to predict the possible trend and trend of space weather, so as to do some support services for the technical systems of aerospace and satellites.

Some high-tech systems, such as satellite operations, aviation flights, and ground pipe networks, may be seriously disturbed by space weather events. When a severely affected catastrophic space weather event occurs, it is necessary to warn and forecast.

The International Civil Aviation Organization (ICAO) recognizes that space weather will affect the safe flight of aviation and hopes to distribute space weather information to the civil aviation department in real time, so it decided to establish a global space weather center.

In 2019, the ICAO Global Space Weather Centre officially opened its doors and began to publish space weather advisories, the first of which was issued at the end of September last year. Since the beginning of this year, as solar activity has gradually increased, several issues of advisory reports have been issued, mainly to remind space weather events of the possible impact on short-wave communications.

Beijing News: Usually people may not "perceive" the changes in space weather, what activities will space weather affect?

Guo Jianguang: In meteorology, when the weather changes slightly, people's feelings are very strong. Space weather is not like this, even if it is a catastrophic space weather, its impact is not felt by most people.

There is more radiation in space than on the ground, so space weather can affect astronaut activities.

For example, our astronauts have recently been walking in space, and their time out of the capsule is considered. The space station orbits the earth, and for a while it will pass through the South Atlantic anomaly, where more high-energy particles are "captured" and the radiation is stronger, and many satellites have failed through this area, so astronauts have to avoid this area. In addition, if a strong solar proton event occurs, the astronauts not only cannot leave the capsule, but also need to enter the shielded cabin to avoid the effects of radiation.

Space weather also has an impact on satellites. Integrated circuit chips on satellites can easily be "overturned" by high-energy particles from the sun, and even damage the detection instruments on satellites. For example, the early Fengyun-1 B star, not long after launch, its attitude was seriously out of control, which was caused by a single particle flipping event. In the later period, researchers made improvements to the satellite, using radiation-resistant chips, and its life was gradually extended.

Specific to people's lives, when the weather in the usual space is good, we can completely ignore this factor and only need to pay attention to it when the catastrophic space weather occurs. For example, mobile phone navigation mainly relies on single-frequency GNSS signals, affected by the ionosphere, itself is not very accurate, if affected by large space weather events, navigation deviation is greater, even up to 100 meters of error. When exploring in the wild or doing geological survey activities related to magnetic fields, it is necessary to avoid the impact of large space weather events.

Studies have found that magnetic field navigation is important when carrier pigeons return home at long distances. After a large magnetic storm, the nesting rate of carrier pigeons may drop from 90%, 80% to 20% and 30%, so the release of carrier pigeons should also pay attention to space weather.

In addition, catastrophic space weather can have an impact on some infrastructure, which can have an indirect impact. For example, in March 1989, the "solar storm" caused a strong disturbance in the geomagnetic field, generating a strong inductive current in the power grid, destroying the voltage device of the Quebec power grid in Canada, causing a 9-hour power outage.

Ultraviolet image of the solar pole of the E-star Fengyun-3. Courtesy of the National Satellite Meteorological Center

Space weather forecast "just stepped on the threshold"

Beijing News: How is the space weather forecast?

Guo Jianguang: Space weather forecasts are not much different from the meteorological weather forecasts we usually see in terms of process, they are monitored first, and then forecasted. The biggest difference between the two is that space weather forecasts mainly monitor the sun.

The driving force for catastrophic space weather basically comes from the sun, such as solar storms, and the solar corona will throw out a large amount of material and energy, and the flight time before they reach the earth is predicted to leave a pre-advance amount.

Solar eruptions are often a series of processes. The first is a flare on the sun's surface, and its effects travel to earth at the speed of light, about 8 and a half minutes. The second wave is the high-energy particles that affect the satellite, and it takes several to a dozen hours from the sun to the earth.

The third wave is some of the material erupted by the Sun, which we call the Coronal Mass Ejection. There is a Lagrange equilibrium point L1 between the sun and the earth, 1.5 million kilometers away from the earth, and the satellite placed there can always be stable on the sun-earth connection line, like a "sentinel", to determine whether the material ejected by the sun can "land" on the earth and where it "lands".

It's like a typhoon forecast, seeing the generation and then forecasting the path. For coronal mass projectile events, we can forecast two or three days in advance.

Beijing News: Compared with meteorological weather forecasts, how accurate is the spatial weather forecast?

Guo Jianguang: In meteorological weather forecasting, first of all, there must be rich observations, and then calculated with numerical forecasting models, and the numerical forecasting model of space weather is under preparation. We have also just stepped on the threshold, and the forecast level of space weather is roughly equivalent to the level of weather forecasting in the 1960s and 1970s.

By observing the changes in the sun and space weather, we also summarized some periodic laws and experience to assist forecasting. There is an interesting phenomenon of solar activity, that is, there is a cycle of about 11 years, there are years of high solar activity, and there are also years of low solar activity. Of course, this can only be said to be a trend, not absolute.

In addition, the sun has a long life, and we have summarized an 11-year cycle based on limited observations, but as future observations continue, the periodic laws of discovery may also change.

Beijing News reporter Wang Jingxi

Edited by Bai Shuang Proofreader Li Lijun