Smoke over the Northern Atlantic Ocean and Iceland, in this image acquired by the MODIS. The smoke is especially visible between Iceland, and Great Britain. Which is peeking out from under the clouds on the right side of the image.
Therefore the smoke likely resulted from fires in Russia. Also Setting fires for agriculture is common in the springtime, and many of the fires causing the smoke over the Atlantic were likely human made.Given the rash of Western wildfires and the propensity for named storms in the subtropical or northern Atlantic Basin, you could argue this satellite image was somewhat iconic of the 2018 Atlantic hurricane season so far.