NewScientist (7 May 2016) reports on what happens when it rains. Feel like sneezing when it comes down? There’s a reason for that:
Rain cleans the air, right? Wrong. On ploughed fields at least, rainfall flings up millions of microscopic organic particles – the remains of dead plants and animals. As well as affecting air quality, this rainfall-induced haze may help to seed clouds and generate more rain. …
So how does rain get particles aloft? Once rainfall starts to puddle, it dissolves organic matter from the soil. “Splashing of subsequent raindrops creates air bubbles, which rise upwards and burst, ejecting a fine mist of organic matter, which then dries into tiny solid spherical balls,” explains [Alexander Laskin]. Light or moderate rain is best; if the rain is too heavy it hits the puddle too hard and doesn’t generate as many air bubbles.
Sure wish the article had discussed the Dust Bowl event in this context.
