After the Solar Storm

We are getting close to a solar maximum. And although it will be a rather weak one, there is plenty of space weather action going on. The last month was dominated by the gigantic sunspot AR 1429, which fired off major flares on March 7th, 10th and 13th (plus some large flares while being on the far side of the Sun).

The flare that occured shortly after midnight on March 7th had the biggest impact here on Earth. The coronal mass ejection (CME) associated with this flare created a major geomagnetic storm. This storm, which raged on 8-9 March, may have been the best predicted geomagnetic storm so far in the history of space weather forecasting. This is solid proof that the scientific understanding, and the observation tools, have greatly improved during the last decade.

The storm also shielded Earth from energetic galactic cosmic rays (GCR), as can be seen in the instrument readings from the Oulu Neutron Monitor in Finland.

Living with space weather

Space weather can have down-to-Earth consequences. Beautiful auroras, of course. Re-routing of trans-polar flights. And in a report published last year, OECD put geomagnetic storms on the list of natural disasters that can have major effects on the world economy.

Nordic power grid operators are well aware of the dangers of solar-induced currents in their networks. A Nordic meeting on these issues was recently held in Copenhagen, and the International Conference on Space Weather and Challenges for Modern Society will be organized in Oslo 22-24 October.

A well documented case

Coming back to galactic cosmic rays, this has of a been a topic of much debate related to climate change. The solar storm in March is a well documented event where the effect on cloud cover and atmospheric temperature can be studied by scientists. NASA har already issued reports on how the enormous amount of energy that was deposited in the upper atmosphere by the CME was observed by satellites. According to NASA, the Earth’s atmosphere glowed and expanded, and air drag on satellite and space debris in low earth orbits increased.

Figure 1: Sunspot AR 1429 erupting on March 7th. (NASA SDO)

Figure 2:  The solar storm caused a significant drop in the galactic cosmic ray level here on Earth. (Oulu Neutron Monitor)


So what about the Sun, the cosmic rays, CO2 and the global temperature here on the ground in the future? Well, there is still plenty of research remaining to answer that one ...