Record-breaking heatwaves hit both Antarctica and the Arctic simultaneously this week, with temperatures reaching 47℃ and 30℃ higher than normal.
Heatwaves are unusual in Antarctica at all times, but especially now at the equinox when Antarctica is about descend into winter darkness. Up north, the Arctic is just emerging as winter.
Are these two heatwaves connected? We don’t know yet, and it’s most likely a coincidence. However, we do know that weather systems in Antarctica or the Arctic are connected with regions closest to them, and these connections can sometimes reach all of the way to the tropical tropics.
And is climate change the reason? It might be. While it’s too soon to say for sure, we do know climate change is making polar heatwaves more common and severe, and the poles are Global average warming is faster than global average.
So let’s take a closer look at what’s driving the extreme anomalies for each region, and the flow-on effects for polar wildlife like penguins and polar bears.
What happened in Antarctica
Antarctica’s heatwave was driven by a slow, intense high pressure system located southeast of Australia, which carried vast amounts of warm air and moisture deep into Antarctica’s interior. It was accompanied with a very intense low pressure over the east Antarctic interior.
The Antarctic ice plateau is surrounded by clouds that trap heat radiating from the surface.
Since it’s autumn in Antarctica, temperatures in the continent’s interior weren’t high enough to melt glaciers and the ice cap. But that’s not to say large swings in temperature didn’t occur.
For example, Vostok in the middle of the ice plateau hit a provisional high of -17.7℃ (15℃ higher than previous record of -32.6℃). Concordia, the Italian-French research station also on the high plateau, experienced its highest ever temperature for any month, which was about 40℃ above the March average.
The story is very different on the coast as rain fell, which isn’t really common for the continent.
It rained. Atmospheric rivers are the primary driver – a narrow band of moisture collected from warm oceans. Atmospheric rivers can transport large quantities of water over vast distances at scales greater that continents. They are located at the edges of low pressure systems.
Despite their rarity, atmospheric rivers make an important contribution to the continent’s ice sheets, as they dump relatively large amounts of snow. Rain falls more often than snow when Antarctica’s surface temperatures rise above freezing.
Last Monday (March 14) air temperatures at the Australian Casey Station reached a maximum of -1.9℃. Two days later, they were more like mid-summer temperatures, reaching a new March maximum of 5.6℃, which will melt ice.
This is the second heatwave in Casey Station. Two years. In February 2020, Casey hit 9.2℃, followed by a shocking high of 18.3℃Antarctic Peninsula
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What does this all mean for wildlife?
Adélie penguins, which live across the entire Antarctic coastline, have recently finished their summer breeding. But thankfully, the Adélie penguin chicks had already left for sea to start hunting for food on their own, so the heatwave did not impact them.
The rain could have had an impact on the local plant life. Such as mossesIt was especially so because they were in their annual dry-out phase for winter. But we won’t know if there’s any damage to the plants until next summer when we can visit the moss beds again.
What about the Arctic?
Similar weather patterns were observed in the Arctic last week. A powerful low pressure system began to form off the coast of the United States. An atmospheric river was formed at the junction of the low pressure system and an adjacent high pressure.
This weather pattern funnelled warm, humid air into the Arctic circle. Svalbald, Norway, recorded a New maximum temperature of 3.9℃.
US researchers called the low pressure system a “bomb cyclone” because it formed so rapidly, undergoing the delightfully termed “bombogenesis”.
Winter sea ice conditions in this year’s Arctic were already very low. Land records have also been broken. Rain across Greenland.
Sea ice that is broken up faster than normal by warm temperatures could have devastating effects on many animals. Sea ice is a vital habitat for polar bears. They can hunt seals and travel great distances with it.
Many people live in the Arctic. We know this because we know many of them. Losing sea iceIt disrupts subsistence hunting, cultural practices, and other activities.
What’s more, the bomb cyclone weather system brought Weather chaosThere are many areas of Northern Hemisphere that are populated. Three weeks of unusually warm weather in northern Norway has led to flowers blooming earlier than usual.
A sign of the future
Modeling shows that large-scale climate patterns are becoming more variable. This suggests that the occurrence of a single heatwave could be a sign of climate change’s future.
Arctic is a prime example of Arctic warming. Double the speedThe rest of the world. This is because the melting sea ice reveals more ocean beneath, and the ocean absorbs more heat as it’s darker.
In fact, the Intergovernmental Panel on Climate Change(IPCC) projects Arctic sea-ice to continue its retreat, with Enjoy ice-free summersIt is possible in the 2050s.
Antarctica’s future looks similarly concerning. The IPCC finds global warming between 2℃ and 3℃ this century would see the West Antarctic Ice Sheet Nearly all of it lost. It is possible to reduce global emissions to net zero as quickly as possible, which will help prevent the worst effects of climate changes.
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