What does a magnetic storm mean?

Magnetic storm refers to the global violent disturbance of the earth's magnetic field under the interference of solar storm.

After the high-speed plasma cloud reaches the earth space, it is the most representative disturbance event of the global space environment. The intensity of magnetic storms can represent the influence of high-speed plasma clouds in solar storms. The intensity grades of magnetic storms are generally divided by two geomagnetic indices Kp indices and Dst indices. Dst index is usually used for research, while Kp index is used for early warning application.

According to the National Space Weather Monitoring and Early Warning Center, a small to medium geomagnetic storm may occur on June 5, 438+February 4, 2023 due to the combined influence of high-speed solar wind and coronal mass ejection (CME) in the solar coronal hole. In 1930s, 65438+2009, when German scientists Gauss and Weber established geomagnetic stations, they found that the geomagnetic field often fluctuated slightly. But they didn't realize that it was caused by the sun.

geomagnetic disturbance

Later, in September of 1859 and June of 1 year, carrington, an Englishman, observed solar flares for the first time while observing sunspots. The next day, the geomagnetic station recorded a strong geomagnetic disturbance of 1600 at Nanoteslas. This accidental discovery and coincidence made him realize that geomagnetic disturbance had something to do with the eruption of the sun. The high-speed plasma cloud ejected from the corona is faster than the background solar wind, carrying the magnetic field of the corona and impacting the magnetosphere of the earth, causing the magnetosphere to compress and deform.

And usually carries a magnetic field rotating in the north-south direction. When the magnetic field turns to the south and interacts with the geomagnetic field, the solar wind will pour huge energy into the large-scale space of the magnetotail, so that a large number of charged particles in the magnetotail plasma sheet will be injected into the circulation. The intensity of the ring current changes, and the changing current will produce a changing magnetic field, which will lead to a global violent geomagnetic disturbance-magnetic storm.