The drought gripping eastern Australia is having consequences as far as 2,000 kilometres away, with the ice on New Zealand glaciers turning red and pink.
Photographs of New Zealand's Mount Aspiring National Park, on the South Island, show discoloured ice across large swaths of the mountains.
Travel blogger Liz Carlson took the images on November 28 while on a helicopter tour of the glacier. On her blog, Young Adventuress, she suggested the odd colour came from the 80 bushfires burning in Australia at the time.
"I just felt profoundly sad," she said.
"Sad for Australia's suffering and sad for our glaciers."
But while Australia is likely the source of the problem, it is dust, not smoke, causing the odd colouring, University of Queensland geographer Hamish McGowan said.
"It's not uncommon to have this occur during periods of severe drought in eastern Australia," he said.
In the right conditions, dust particles can be blown across the Tasman Sea by north-westerly winds, coming down on the Southern Alps in rain or snow and leaving behind an orange discolouration, Professor McGowan said.
"There is most likely also ash being deposited on the snowfields of the Southern Alps, but this would be visible as a dark or black discolouration of the snow and ice," he said.
The same phenomenon can be seen in the Australian Alps.
Record-breaking dust clouds
Dust storms have been occurring with record-breaking frequency in Australia in 2019, the citizen-science program DustWatch reported.
Some towns in New South Wales recorded more than 200 hours of dust during the month of October.
Both dust and smoke clouds have reached New Zealand from Australia in the past, the Bureau of Meteorology confirmed.
The so-called "red dawn" dust storm in September 2009 blanketed Sydney with red particles, with visibility reduced to 400 metres at its worst point. Dust particles were found not only in New Zealand, but as far north as Cairns.
Winds from Australia are not the only threat to New Zealand's glaciers. A 2014 study of the Franz Josef Glacier found the pace of erosion was likely to speed up as global temperatures rose due to climate change.
