Scientists working in Antarctica have captured stunning photos of the sky over the icy continent. According to New Zealand’s NIWA (National Institute of Water and Atmospheric Research), the effect is believed to be caused by a resulting abundance of aerosols in the stratosphere 15 to 24 kilometers above Antarctica. The breathtaking spectacle is likely to have been triggered by the eruption of the Hunga-Tonga Ha’apai volcano earlier this year.

“Usually in mid-winter, Antarctica is nearly continuously dark, except for a slight ‘nautical twilight’ at around midday which means the horizon is faintly visible in good conditions. But this year, we were presented with quite a show, which had most of the station personnel grabbing jackets and running outside with their cameras to look at the awesome colours. Believe it or not, I haven’t edited these shots either, they are pretty much as we saw it. It’s incredible”, said Stuart Shaw, a technician at New Zealand’s Scott Base in Antarctica.

Tongan volcano triggered the spectacle

Nava Fedaeff: “Stratospheric aerosols can circle the globe for months after a volcanic eruption, scattering and diffracting light as the sun dips below the horizon or rises, creating a glow in the sky in shades of pink, blue, purple and violet. These volcanic twilights are known as “afterglows,” with color and intensity depending on the amount of haze and cloud cover along the light path that reaches the stratosphere.”

The aerosols are mainly sulfate particles, but since this was an underwater eruption, water vapor droplets as well as sea salt are likely in the mix.

On December 20, 2021, Hunga-Tonga Ha’apai in the southern Pacific Ocean began activity. The submarine volcano reached the peak of eruptions almost four weeks later, on January 15, 2022, with a very large and powerful eruption. (Video: Youtube Weather Alert)

“Nature never fails to put on a show in Antarctica, and it can be beautiful or destructive”, says Antarctica New Zealand’s Chief Scientific Advisor Jordy Hendrikx.

“These photographs capture the awe it inspires, and how connected our planet is. Antarctica is some 5000km from New Zealand, some 7000km from Tonga, but we share our skies.”

“What happens in Antarctica affects us at home, and the other way around too. Much of the science that we support aims to understand those dynamics in the atmosphere, oceans, and ecosystems, and to help better understand the connectivity between Antarctica, New Zealand, and the wider world”, says Jordy Hendrikx.

Heiner Kubny, PolarJournal