From the evening of June 28 to the early morning of June 29, 2024, Beijing time, the earth's magnetic field suddenly underwent a strong disturbance, and a geodetic magnetic storm event occurred. The geomagnetic field reached the geomagnetic storm level (Kp=8) for 3 hours, which was the orange alert level. The level of moderate magnetic storm (Kp=6) was reached in 3 hours, and the level of small geomagnetic storm (Kp=5) was reached in 6 hours, which was the yellow alert level.
Fig. 1 Magnetic K index observed at Mohe, Beijing, Langfang, Hainan Fuke, and Sanya stations during the geomagnetic storm (UTC) on 28 June (Meridian Project and Space Center Station)
The magnetic storm event was caused by a coronal mass ejection (CME) that accompanied the dark stripe eruption on the Sun on the 25th.
Figure 2 Solar dark bar eruption on June 25 (Universal Time).
Fig. 3 CME accompanied by the dark bar eruption on June 25 (UTC).
On June 28, a large number of plasma clouds from the CME that erupted on the 25th reached the vicinity of Earth. Under the influence of solar wind, the speed of the solar wind increases from about 300 km/s to about 500 km/s, the intensity of the interplanetary magnetic field jumps to 30 nT, and the southward magnetic field component is as low as -22 nT. Under the combined action of the high-speed solar wind and the continuous interplanetary southward magnetic field component, a strong geomagnetic disturbance at the level of a geodetic magnetic storm occurred.
Fig. 4 Solar wind parameters and geomagnetic index for June 26-29 (Universal Time).
The magnetic storm has been going on for 12 hours now. This geomagnetic disturbance is expected to continue for about 1 day.
We will pay close attention to the development of the near-Earth space environment and keep it informed in a timely manner.
Please check our website for www.sepc.ac.cn forecast.