Round up of UK aurora 01-02 March

/ 2017-03-02

It’s been a quiet start to the new year for aurora watchers in the UK, with only a single amber alert being issued in the whole of January and February combined. Perhaps this isn’t unsurprising considering that we are currently heading into a solar minimum, a drop in solar activity resulting from the Sun’s 11-year cycle. But, as reported by AuroraWatch UK team member Dr Nathan Case in this article, this doesn’t mean that the beloved northern lights will completely vanishing anytime soon.

AuroraWatch UK alert status

On March 1st 2017, going into the morning of the 2nd, the UK received a whopping 13 total hours of elevated geomagnetic activity with 5 of those hours strong enough to trigger an amber alert level.

AuroraWatch UK geomagnetic activity and alert levels for 01-02 March 2017.

Cause of activity

This rise in activity was predicted by the NOAA Space Weather Prediction Centre last week. They cited something called a ‘negative polarity coronal hole high speed stream’, or a just a CH HSS for short, as the cause. We go into some more detail on coronal holes, and what they mean for the aurora, in one of our previous posts. The ‘negative polarity’ part of the name refers to the Sun being like a big bar magnet in space, just like the Earth but much bigger:

A picture of the Sun with magnetic field lines drawn on top in red and blue. Image source: https://svs.gsfc.nasa.gov/11429

In the image above, the red lines show the solar magnetic field coming out of the north pole and going into the south pole in blue. The CH HSS we experienced was negative polarity because it was located near to the solar south pole, so the magnetic field was travelling into it. This is simplified however, as there is usually a lot more going on causing a big mess of field lines like this:

A closer look at what the Sun’s magnetic field looks like. Credits: NASA/SDO/AIA/LMSAL

Because the Sun is so huge, it’s magnetic field extends not only to Earth, but past all the planets in our solar system and into interstellar space (right where the Voyager 1 probe is right now!). 

The effects of the CH HHS are expected to diminish in the coming hours and so further activity is unlikely, but possible.

UK Sightings

The past few days have seen a bit of a mixed bag weather-wise, with half the country seeing some rain and the other half clear skies. The north of the country, which is the best place to be to see the northern lights, for the most part had good viewing conditions. As we can see from the photos below, large parts of Scotland and Northumbria (England) were in for a particularly good show.

Isle of Bute, Scotland

Berwick Upon Tweed, England

Consett, England

The Met Office also posted this breathtaking image, captured using a satellite owned by NASA/NOAA, of the aurora hanging out close to the UK from space:

That’s all for this roundup of last night’s activity. Remember you can follow us on Facebook and Twitter for up to date alerts on auroral activity in the UK. We also have a Flickr group where some of our favourite photographers share their images with us!

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