hi Brian!

The strongest storm took place in September 1859. This is also a famous storm since it was associated with the first and the strongest flare ever recorded. The flare was observed by Richard Carrington who was making his routine sunspot observations. At his surprise he witnessed how suddenly a bright light broke over the sunspots. In less than a day unusually bright auroras covered the skies even near the tropical latitudes.

Today we know that the magnetic storm is not caused by a flare itself, but a huge magnetized plasma cloud, coronal mass ejection, that often are hurled out of the Sun about at the same time.

Carrington super-storm has been evaluated the largest storms by the energetic particle observations that leave traces in the artic ice and by magnetogram observations.‘Dst’ is a geomagnetic index that scientist use to determine how strong the magnetic storm is. Dst is calculated from magnetogram observations and it has been calculated only since the late 1950s. The strongest storm when Dst measurements have been available occurred on 13 March 1989. However, it has been evaluated that the Carrington storm was clearly stronger than this storm.