Nearby, “caramelized” snow appeared atop mountain peaks along the Franz Josef Glacier. The snow reportedly was pure white one day earlier.
Meanwhile, the BBC reported “eerie” sunrises visible from Auckland. Elsewhere, the sky appeared ominously yellow.
Time-lapse video showed the unusual changes as a narrow but dense channel of smoke passed over Portobello on New Zealand’s South Island.
The New Zealand Meteorological Service called for “hazy sunrises” across the nation Thursday as twin bands of smoke swept through. By Thursday morning, one strip of smoke was exiting north, while the other lingered over South Island. The Met Service anticipated a “tinge of orange” accompanying sunset in some locales, but it said most of the smoke dissipated throughout the day.
However, New Zealanders are bracing for more smoke by the weekend.
Where the smoke is coming from
More than 150 fires were burning across New South Wales, Australia, as of Friday morning local time. On New Year’s Day, eight of them prompted “emergency warnings,” the most severe type of alert that can be issued. It is ordinarily reserved for dire situations when it is “too late to leave.”
The flames there and in Queensland have torched nearly 10.1 million acres so far and show no signs of easing. That’s equivalent to an area the size of a box 130 miles on a side. That’s about 16,700 square miles, larger than each of the nine smallest U.S. states and roughly 35 percent more expansive than Maryland.
The bush fires — which have claimed 18 lives — are producing choking smoke and dangerous toxic pollution. The air quality index at Omeo in Victoria state was the worst found anywhere in the world for a time Thursday morning Eastern time. Air quality indexes over 200 are considered hazardous for health; values there exceeded 999. On Wednesday, the air quality index in Canberra spiked to more than 20 times the hazardous level, its worst pollution on record.
In New Zealand, air quality levels in several locations declined to “code orange” Friday local time, meaning unhealthy for sensitive groups.
The fires have been releasing extreme amounts of smoke, soot, ash and numerous chemical compounds. Scientists have been tracking the progress of the smoke eastward. Among them is Mark Parrington of the European Center for Medium-Range Weather Forecasts. He called the level of smoky emissions “highly unusual.”
“Our data shows that fire emissions across [southeastern] Australia (New South Wales plus Victoria and South Australia) have been higher than has been observed since 2003 for the same period,” Parrington wrote. The particular data in question only extends back to 2003.
“The thick smoke that can clearly be seen in the latest satellite imagery reaching beyond New Zealand to the South Pacific Ocean also reflects how intense and dangerous the fires are.”
How it’s getting to New Zealand
The smoke began to seize New Zealand earlier this week as jet-stream wind lofted it in from the west. It came in a bifurcated — or split — atmospheric flow, multiple rivers of smoke targeting the country of 4.8 million. Satellite estimates indicate that the smoke continued another thousand miles thereafter through the South Pacific, traveling more than 2,000 miles total before dissipating.
Part of what helped focus the tongue of smoke lapping at New Zealand was an atmospheric squeeze play of sorts, with clockwise-spinning low pressure to the south pressed against a counterclockwise high to the north. The convergent flow in between scooped up the smoke, while westerly winds acted like a conveyor belt aimed at New Zealand.
More smoke could be in the offing
As fires continue to rage, it’s looking as though weather conditions will line up again to channel more smoke to New Zealand.
Cooler southerly winds will overspread most of New Zealand into the weekend ahead of high pressure. By Sunday, that high will retreat to the north as a strong storm system develops to the south over the Tasman Sea. That will position the jet stream almost ideally to bring a dose of hefty smoke to much of New Zealand.
The climate context
What’s happening in the Southern Hemisphere isn’t just coincidence. Climate change is a significant factor in exacerbating the wildfires afflicting Australia and now, by extension, New Zealand.
According to data from the Australian Bureau of Meteorology, 2019 was both the hottest and driest year ever measured in Australia.
Australia saw its hottest day nationally just last month, as the country’s nationally averaged maximum temperature hit 107.4 degrees Fahrenheit (41.9 Celsius) on Dec. 18. Hotter temperatures foster the evaporation of water from fuels, setting the stage for more destructive wildfires.
An additional contributor to the disastrous 2019-2020 fire season has been a strong Indian Ocean Dipole (IOD), or an atmospheric overturning circulation that favored much drier than average conditions across Oceania. While this circulation varies naturally, “its behavior is changing in response to climate change,” Australia’s Bureau of Meteorology wrote. “Research suggests that the frequency of positive IOD events, and particularly the occurrence of consecutive events will increase as global temperatures rise.”
The spate of extreme fires demonstrates how natural variability can combine with human-caused climate change to lead to disaster.