A severe geomagnetic storm occurring over recent days brought with it exceptionally bright aurora borealis – or Northern Lights. The US Space Weather Prediction Centre said the storm peaked over 18 March, but said it has now largely subsided.

The display is a natural phenomenon caused by charged particles – mostly electrons and protons – entering the atmosphere from above, causing ionisation and excitation of atmospheric constituents. However, a geomagnetic storm creates conditions perfect for aurora borealis.

During the storm, photographer Sebastian Saarloos captured images of the display over Alaska. Explaining his pictures, he said: "The auroras were amazing last night [18 March] and it was the most colour that I've ever seen. The auroras also lasted longer than usual. Often I'll see red or purples for a few minutes but last night it lasted hours. The only reason I stopped photographing was because I was physically exhausted from walking through knee deep snow and fighting 35mph winds.

For more images visit Sebastian Saarloos Facebook page

Aurora Borealis
Northern Lights over AlaskaSebastian Saarloos
Aurora Borealis
Sebastian Saarloos
Aurora Borealis
Sebastian Saarloos
Aurora Borealis
Sebastian Saarloos
Aurora Borealis
Sebastian Saarloos
Aurora Borealis
Sebastian Saarloos

"It was quite warm at 30F, so cold wasn't a factor, and the adrenaline kept me warm. I'm looking forward to another great night tonight, but last night will be hard to live up to."

Aurora Borealis
Aurora Borealis over AlaskaSebastian Saarloos