A major geomagnetic storm is under way, delivering yet more spectacular displays of aurora in southern Australia and New Zealand.
Solar winds created by ejections from the sun peaked in the early hours of Tuesday, supercharging displays of the southern lights on Monday night. The magenta, amethyst and ruby aurora was visible in Tasmania, Victoria and New South Wales, and from New Zealand’s South Island.
Australia’s Bureau of Meteorology said the storm was easing on Tuesday afternoon, but that aurora australis – caused by particles from solar winds entering the Earth’s atmosphere – may still be observed in good conditions and at high latitudes.
Meteorologist Angus Hines predicted the lights will be visible primarily in Tasmania and from New Zealand’s south as the storm eases off.
“We had a G4 geomagnetic storm last night and auroras were visible in many parts of southern Australia but throughout today and certainly into tonight we are expecting geomagnetic activity to decrease,” he said.
Aurora australis 3.45am 13th August 2024 From Trentham, Victoria #aurora @VicStormChasers @KLijnders @BOM_Vic pic.twitter.com/u7RQQCL1OI
— AustraliaSkynWeather (@AUSSKY) August 12, 2024
…and it just got better and better from the front yard. Trentham, Victoria 10.35pm 12th August 2024 #aurora @VicStormChasers @KLijnders @BOM_Vic pic.twitter.com/c6zPl5PNzJ
— AustraliaSkynWeather (@AUSSKY) August 12, 2024
Pendergast Hut snowcam tonight https://t.co/W2LheuZNyK pic.twitter.com/ROhCjEQE0H
— Mt Buller (@mtbuller) August 12, 2024
iPhone images (10 sec exposures) from Little Hampton and Trentham in the Victorian central ranges. 12th August 2024 #aurora @VicStormChasers @KLijnders @BOM_Vic pic.twitter.com/NTVIXLLMHo
— AustraliaSkynWeather (@AUSSKY) August 12, 2024
The show was visible as far north as Albury and Wodonga on NSW’s southern border:
My incredible view of the Aurora Australis from #Albury & #Wodonga tonight at around 10:30pm AEST @BOM_Vic @VicStormChasers @AUSSKY @weatherzone pic.twitter.com/5R8d3w7xU4
— Liam D (@Tempest08246085) August 12, 2024
In New Zealand, magenta skies above the Otago peninsula on Monday evening were accompanied by a little-understood phenomenon known as Steve – an acronym for strong thermal emission velocity enhancement.
Steve appears as a streak of light across the sky and is the result of the same processes that create auroras.
The celestial displays are caused by electrically charged particles and gas from coronal mass expulsions escaping the sun’s gravitational pull and entering the Earth’s atmosphere, accumulating at the north and south poles.
When the particles collide with oxygen in the Earth’s atmosphere, intense displays of red and green can be seen, while collisions with nitrogen in the atmosphere yield purple and blue auroras. Most of the light is not visible to the naked eye.
The stronger the storm, the further from the poles auroras can be spotted. The bureau’s space weather forecasters have downgraded the current storm from a “Kp index” rating of 6 to 5, with further falls predicted, meaning that the lights will only be visible in the far south of Australia.
But, with much of southern Western Australia, South Australia, Victoria and NSW shrouded in clouds on Tuesday, further celestial shows could remain hidden for many.
The same geomagnetic storm is creating celestial spectacles closer to the north pole, too. Onlookers in the northern hemisphere were treated to Technicolour displays of the aurora borealis, which on Monday evening was seen as far south as Brandenburg in Germany.
Aurora australis was observed across Australia and New Zealand at the end of July, while in May, Australians witnessed one of the most significant displays of the aurora in decades, when the “extreme” celestial show was on view over two nights across the southern hemisphere.
