Even on the coldest place on Earth, Antarctic expeditioners can still get sunburnt, and this year it’s an even greater risk.

The ozone hole over Antarctica opened earlier and larger than normal this year, likely due to a volcanic eruption in the Pacific Ocean in 2022.

The ozone layer in Earth’s atmosphere absorbs harmful ultraviolet light from the Sun, but since the late 1970s, the ozone hole has increased the risk of sunburn for life in Antarctica.

Sunburn is a hazard that all Antarctic expeditioners need to protect against.

By monitoring and understanding changes in the ozone layer, we are better anticipating future climate, as well helping to protect the people of the Australian Antarctic Program.

Australian Antarctic Program atmospheric scientist, Dr Andrew Klekociuk, said that each year the annual opening of the ozone layer starts around August in Antarctica, peaks in September and then drops away by December.

“Climate variability causes the ozone hole to be a little bit different every year, but this year the unusual thing was the ozone hole opened early,” he said.

“This appears related to the Hunga Tonga–Hunga Ha‘apai volcano eruption last year, which shot water vapour into the stratosphere.”

The water vapour influenced the balance of chemical reactions in the ozone layer.

This year the ozone hole at its peak size covered 26 million square kilometres, almost three and a half times the size of Australia.

But in good news the ozone hole was smaller this year than during the 2000s, continuing the long-term repair that the international Montreal Protocol agreement is delivering.

“As the hole starts to shrink towards summer, it starts to wobble around over Antarctica and our stations,” Dr Klekociuk said.

“With less ozone, and the sun higher in the sky, quite high UV indices can occur.”

“You can get tropical indices or even greater numbers. We’ve seen that at our stations. Sometimes we will get values that are well over what you would experience back in Australia, with values up to 14.”

The vast white surface of ice that covers Antarctica is highly reflective, which enhances the effect of the UV radiation recreating the effect of being on a ski holiday.

“You can get burnt in places you wouldn’t normally think, such as under the nose and behind the ears,” Dr Klekociuk noted.

Even on the coldest place on the planet, Australian Antarctic Program participants are advised to take the same precautions as a day out in Australian summer.

With the average temperature below –10 degrees, expeditioners don’t need to be reminded to ‘slip’ on a shirt, but slopping on SPF 50+ sunscreen and Antarctic sunnies is a must, as the continent nears almost 24 hours of sunlight.

Dr Jeff Ayton, Chief Medical Officer at the Australian Antarctic Division, says that while the ozone hole opens every year, it is a timely reminder to participants to be aware of their UV exposure risk while in Antarctica.

“We ask participants to reconsider their exposure as the days get longer and the UV levels increase and peak,” he said.

“We suggest they wear appropriate protective clothing, sunsafe headwear and glacier glasses, and apply SPF 50-plus sunscreen generously and frequently to exposed skin."

“We also ask them to think about the task they are going outside to do. Do they need to do it in the peak of the UV exposure? Are they adequately protected? Can they do it in the shade?

“We want to prevent short-term damage with sunburn, and snow-blindness and potential long-term damage that leads to skin cancers, cataracts, and other damage to the eyes.”

All Australian Antarctic Program participants are provided with PPE for all Antarctic conditions, including to slip, slop, slap, seek and slide.