What causes solar flares?
The surface of the Sun is constantly throwing out charged particles which is commonly known as solar wind. The speed of this wind varies constantly and the speed and angle of impact of it on our magnetic field affects the level of aurora activity over the planet.
We run our Northern Lights tours directly underneath what is known as the auroral oval. For us this means we see the Aurora Borealis on average every other night, regardless of how strong the solar wind is. Sometimes it can be faint and slow moving and sometimes it can be bright and fast moving. There are lots of other factors affecting the level of aurora activity too.
Black sunspots that appear on the Sun’s surface are caused by a cooling process which in turn is created by charged particles in convection zones below the surface. These constantly moving convection zones create their own magnetic field which, when strong enough can stretch the charged gases away from the surface of the sun. This magnetic effect stretches more and more until the furthest point of the magnetic loop snaps away from the pull from the surface, taking some of the charged gases or plasma with it. This magnetised plasma escapes the sun at speeds of up to 8 million kilometres per hour and is called a Coronal Mass Ejection (CME).
You can learn more about what causes an aurora in this short animation our 4 children made about the Wibbly Wobbly Green Stuff
What happens when the solar storm reaches Earth?
At the moment we are still waiting for the Space Weather experts to give us more detail but it seems quite likely that the aurora will be much further from the poles than is normal. In other words the auroral oval will be larger and stretch further south. We will post more information about this as and when we find out. Until then we are all waiting, camera gear ready to go.
When will the solar storm arrive? [updated: 08/09/17 10:00 UTC]
UPDATE: 08/09/17 10:00 UTC
It looks like the solar storm from the X9 flare has hit a little earlier than originally predicted. At around 22:30 UTC on 7th September the density of the solar wind increased massively, the magnetic component flipped south and the already fast solar wind speed jumped from 500km/s to 900km/s – with a few moments of around 1100km/s! A Kp level of 8 was reached at around midnight which is classed as a G4 solar storm.
Northern parts of Europe including Norway, Finland, Sweden, Iceland & Greenland had incredible displays! The lights would have been visible across much of the UK and Northern parts of Germany and the Netherlands, although a lot of cloud cover made this difficult. The BBC have just published an article about the lucky people in Scotland who got to see and photograph the display. http://www.bbc.co.uk/news/uk-scotland-41199051
Forecasters predict the storm to continue on into the night of 8th September with G3 storms still expected!
UPDATE: 07/09/17 11:30 UTC
A very recent prediction from the NOAA looks great for people in Europe, including all parts of England, Wales, Ireland, Scotland, Germany, Netherlands and possibly even further south with the huge X-flare produced CME impacting around 16:00 UTC on Friday September 8th. It will then build to a very high level of Kp7+ between 21:00 and 03:00 UTC. This could be fantastic for anyone looking to see the Northern Lights in Northern parts of Europe! We will update this post when we have more information.
So all that remains to be said is if you are in the usual place where you would see an aurora you are likely to be needing to face south tonight! For everyone else who is just beyond the reach of an aurora tonight could be your night! You may just find yourself dancing with the Tricky Lady!