February 28, 2019, 09:30 UTC

A magnetic storm planned a month ago happened exactly on schedule

The ring of auroras on 28 February 2019 The ring of auroras on 28 February 2019 as the result of exposure to the solar wind. Model of NOAA.

Magnetic storm of the minimum first level is recorded today on the Earth between 3 and 6 hours period, Moscow time. The event was observed against the background of extremely low solar activity associated with the passing of our star through the minimum of the 11-year solar cycle. Storms of this level, in accordance with classification, are capable of causing weak fluctuations in energy systems, as well as exerting an insignificant effect on spacecraft control systems. Appearance of auroras are possible at high geographical latitudes from 70 to 80 degrees.

The reason for the magnetic storm was the passing of the Earth through a high-speed solar wind region which exerts increased pressure on Earth's magnetic field and increases its instability. The wind flow has a considerable width, so the separate disturbances of the magnetosphere can be observed throughout the coming days, however, according to the forecast, their level should be lower. The probability that it will repeatedly exceed the threshold from which the event is classified as a storm - is less than 10%.

The event that happened was remarkable because the storm was predicted with high accuracy about a month ago. This possibility is associated with extremely low solar activity against which the global structure of the solar magnetic field changes extremely slowly. As a result, there is possibility of very accurate forecast for 1-2 months in advance, which is not possible in the years of the maximum activity with high dynamics of solar active processes. If the current trend continues, then we can predict geomagnetic activity for the entire coming month. According to such a forecast, not a single magnetic storm is expected in March. Separate geomagnetic disturbances of an extremely low level can be recorded on the 8th and 12th.

Laboratory of X-ray astronomy of the Sun, Lebedev Institute, Russia