Monitoring the Arctic Heatwave: Alarmingly High Temperatures, Extreme Wildfires and a Significant Loss of Sea Ice

https://scitechdaily.com/monitoring-the-arctic-heatwave-alarmingly-high-temperatures-extreme-wildfires-and-a-significant-loss-of-sea-ice/

By European Space Agency September 5, 2020 

Over the past months, the Arctic has experienced alarmingly high temperatures, extreme wildfires and a significant loss of sea ice. While hot summer weather is not uncommon in the Arctic, the region is warming at two to three times the global average – impacting nature and humanity on a global scale. Observations from space offer a unique opportunity to understand the changes occurring in this remote region.

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Although heatwaves in the Arctic are not uncommon, the persistent higher-than-average temperatures this year have potentially devastating consequences for the rest of the world. Firstly, the high temperatures fuelled an outbreak of wildfires in the Arctic Circle. Images captured by the Copernicus Sentinel-3 mission show some of the fires in the Chukotka region, the most north-easterly region of Russia, on 23 June 2020.

Wildfire smoke releases a wide range of pollutants including carbon monoxide, nitrogen oxides and solid aerosol particles. In June alone, the Arctic wildfires were reported to have emitted the equivalent of 56 megatonnes of carbon dioxide, as well as significant amounts of carbon monoxide and particulate matter. These wildfires affect radiation, clouds and climate on a regional, and global, scale.

The Arctic heatwave also contributes to the thawing of permafrost. Arctic permafrost soils contain large quantities of organic carbon and materials left over from dead plants that cannot decompose or rot, whereas permafrost layers deeper down contain soils made of minerals. The permanently frozen ground, just below the surface, covers around a quarter of the land in the northern hemisphere.

When permafrost thaws, it releases methane and carbon dioxide into the atmosphere – adding these greenhouse gases to the atmosphere. This, in turn, causes further warming, and further thawing of the permafrost – a vicious cycle.

According to the UN’s Intergovernmental Panel on Climate Change Special Report, permafrost temperatures have increased to record-high levels from the 1980s to present. Although satellite sensors cannot measure permafrost directly, a recent project by ESA’s Climate Change Initiative (CCI), combined in situ data with satellite measurements of land-surface temperature and land cover to estimate permafrost extent in the Arctic.

The thaw of permafrost is also said to have caused the collapse of the oil tank that leaked over 20,000 tonnes of oil into rivers near the city of Norilsk, Russia, in May.

The Siberian heatwave is also recognised to have contributed to accelerating the sea-ice retreat along the Arctic Russian coast. Melt onset was as much as 30 days earlier than average in the Laptev and Kara Seas, which has been linked, in part, to persistent high sea level pressure over Siberia and a record warm spring in the region. According to the Copernicus Climate Change Service, the Arctic sea ice extent for July 2020 was on a par with the previous July minimum of 2012 – at nearly 27% below the 1981-2020 average.

ESA’s Mark Drinkwater comments, “Throughout the satellite era, polar scientists pointed to the Arctic as a harbinger of more widespread global impacts of climate change. As these interconnected events of 2020 make their indelible marks in the climate record, it becomes evident that a ‘green’ low-carbon Europe is alone insufficient to combat the effects of climate change.”

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