According to the National Space Weather Monitoring and Warning Center of the China Meteorological Administration, a geomagnetic storm occurred from 20 o'clock to 23 o'clock on December 1, and auroral activities occurred in many places in China. So, what is a geomagnetic storm?Will there be any more aurora events in the future?
Coronal mass ejection process captured by a coronagraph carried by the SOHO satellite.
Due to the low geomagnetic latitude in China, it is difficult for obvious auroras to occur even when strong geomagnetic activity occurs.
Take a real shot of the aurora. Photo by Tu Shangrui of the Amur Forestry Bureau in the Daxinganling Mountains.
However, the altitude of the aurora is often 100 kilometers or even 300 to 400 kilometers in the sky, such a high altitude is enough to cross thousands of kilometers of horizon, and when the right conditions are encountered, the aurora may also be seen in the extreme north of China (such as Xinjiang and Heilongjiang). What's even more exciting is that this time someone in Beijing, which is lower than the latitude, also photographed the aurora.
The National Space Weather Monitoring and Warning Center of the China Meteorological Administration said that solar activity is relatively frequent at present, and auroral activity will occur in the future. Low to moderate levels of solar activity are expected over the next three days, with the potential for a flare of magnitude m or higher. Due to the continuous influence of CME, geomagnetic activity or even small geomagnetic storms may occur on the 2nd, and geomagnetic activity may be calm to slightly perturbent on the 3rd, and small to moderate geomagnetic storms may occur on the 4th due to the combined influence of the coronal hole and the CME on the 1st. In addition, on the 2nd, moderate disturbances may occur in the ionospheric weather in most parts of China, and small disturbances may occur in the ionospheric weather on the 3rd-4th.
Previously, the National Space Weather Monitoring and Warning Center of the China Meteorological Administration issued a forecast that geomagnetic storms may occur on November 30, December 1 and December 2, among which, geomagnetic storms above moderate or even geomagnetic storms may occur on December 1. Under this influence, the orbital altitude of the space station may decrease due to atmospheric drag, the error of satellite navigation equipment will increase, and the aviation flight will face the double risk of deterioration of the communication environment and radiation across the polar region.
So, what is a geomagnetic storm?As the most typical solar eruption activity, a coronal mass ejection process can throw hundreds of millions of tons of solar material off the surface of the sun at a high speed of hundreds of kilometers per second, not only the kinetic energy of the huge mass and velocity convergence, but also the powerful magnetic field energy of the sun, once it hits the earth, it will cause a change in the direction and magnitude of the geomagnetic field, that is, a geomagnetic storm.
With the gradual intensification of magnetic storm activity, the Earth's upper atmosphere is continuously heated, and then expands and spreads into higher space, which creates additional drag for the spacecraft to fly in orbit, resulting in a deceleration effect similar to dragging, reducing the orbital altitude of the spacecraft, and the reduction of altitude corresponds to a denser atmospheric environment, which will further bring greater flight resistance, so that the flight speed is slowed down - the altitude is reduced - the drag is greater - further deceleration - The vicious circle of faster altitude reduction poses a great threat to the safety of spacecraft.
Of course, geomagnetic storms are not all bad, such as the occurrence of auroras.
*: China Weather Network).