Forests in Canada are ablaze, with 2.2 million acres going up in flames so far this year in British Columbia alone. These fires, and others in the Yukon and Northwest Territories, have been belching smoke into the air, in some cases up to 8 miles high.

Once in the atmosphere, weather patterns are causing the wildfire smoke to converge into a blanket so thick it's blotting out the sun across northern Canada. This smoke is working its way to the high Arctic, where it could speed up the melting of sea and land ice.

According to NASA, the smoke has set a record for its thickness, and has been especially dense across the Northwest Territories, Yukon, and Nunavut provinces.

Never mind the upcoming total solar eclipse — in some places, the smoke is so thick it could turn day into night, according to Mike Fromm of the U.S. Naval Research Laboratory.

“There’s that much aerosol in the air,” Fromm said, according to NASA's Earth Observatory. Aerosols are small particles, such as soot or volcanic ash, that reflect incoming sunlight.

Aerosol index across Canada during the past several days. Image: NASA Earth Observatory images/Colin Seftor.

According to Colin Seftor, an atmospheric researcher for NASA’s Goddard Space Flight Center, on August 15, the Ozone Mapping and Profiler Suite (OMPS) on the Suomi NPP satellite recorded aerosol index values as high as 49.7. This was more than 15 points higher than the previous record, which was set in 2006 by fires in Australia.

Aerosol index records were also set on August 13 and 14, NASA reported. Although the Suomi NPP satellite is quite new, the satellite aerosol index dates back to the Nimbus-7 satellite in 1978, giving scientists a longer data set.

According to NASA, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured particularly heavy smoke obscuring a wide swath of northern Canada as of August 15, 2017.

Another satellite image, this time from the Aqua satellite, shows smoke billowing north from areas near Lake Athabasca. The fires in British Columbia were intense enough to produce numerous pyrocumulus clouds, which are essentially firestorms that tower into the sky, resembling thunderstorms.

Such clouds can vault smoke high into the atmosphere, all the way to the stratosphere, where it can linger for days or longer.

The Canadian fires are important for several reasons. First, they signal the transition to a more combustible future in the Far North, as climate change makes conditions more conducive to large wildfires.

Smoke forecast with rectangle showing the area of smoke transport into the Arctic. Image: copernicus/ECMWF

Second, they are ideally located to directly feed smoke toward vulnerable Arctic sea ice and the Greenland Ice Sheet. In addition to altering the heat balance of the atmosphere, the smoke can deposit dark soot particles on the ice, which hastens melting by lowering the reflectivity of the ice and causing it to absorb more incoming sunlight.

Studies have tied the increasing number of large fires in parts of Canada and the U.S. to global warming. In fact, the level of fire activity across the boreal forests, which stretch from Alaska to Canada and around the top of the world to Scandinavia and Russia, is unprecedented in the past 10,000 years, according to a study published in 2013.