battle of the monitor and the merrimack

The fine particles are mostly made from gases. There are four major origins for that gases which are responsible for these particles: rock (vaporized during combustion or casting), carbon from combustion, organic carbon, sulfates and nitrates. Take sulphur dioxide. It is created during engine combustion, but when it climbs into the atmosphere and mixes with rain it will become sulphuric acid. We all probably know very well what that will do- since it is highly corrosive and dangerous in concentration. This picture amazingly captures the think layer of clouds on the valley near the south of Lake Como, northern Italy. In the above image, the dense cloud hides almost the valley and leaves some artificial lights which make the town as an opaque blanket. The village over distance is clearly seen from the blanket.