It's been a particularly brutal bushfire season in parts of western North America, as several large blazes continue to cause headaches from California up to British Columbia. As shocking new satellite images show, the smoke from these fires hasn't been limited to the US West Coast, or even the North American continent. It's drifted all the way over the Atlantic Ocean into European skies.
Natural-colour image showing smoke across the upper Midwest on 13 September 2017. (Image: NASA/Moderate Resolution Imaging Spectroradiometer (MODIS))
This series of images was produced by the Ozone Mapping Profiler Suite (OMPS) on Suomi NPP satellite, and they show aerosol concentrations from September 4 to 7. Aerosols are a mixture of fine solid particles or liquid droplets, with smoke being a good example of the former. High aerosol concentrations are shown in dark orange-brown, while lower concentrations are shown in yellow.
Image: Jesse Allen/Jeff Schmaltz/Suomi NPP OMPS/Colin Seftor (SSAI)
As the smoke from western bushfires drifts higher and higher, it's picked up by strong prevailing winds that take it across the continent and towards the Atlantic ocean. Incredibly, smoke that was above the Pacific Northwest on September 4 drifted to parts of western Europe in just four days, with traces of aerosols appearing over Ireland, the UK and northern France.
"You can see that the smoke cloud on September 6 is part of the long stream of smoke emanating from the Pacific Northwest," Colin Seftor, an atmospheric scientist working for NASA's Goddard Space Flight Center, told NASA's Earth Observatory. "It almost looks like it was flung across the Atlantic." Seftor says that it isn't uncommon for smoke from fires in North America to reach Europe, but the smoke from this year's blazes seems to be larger, thicker and more persistent than usual.
As NASA's Earth Observatory points out, these aerosols are high up in the atmosphere, so they're not a threat to human health, nor do they affect air quality at ground level. But the dramatic movement of airborne particles shows how something that happens in one part of the world can produce effects halfway across the globe.