Wednesday, 8 August 2018

It was more dust than rain.

It rained for a few minutes, just long enough to wash all the dust out of the air. It dried very quickly and gave my car a surprisingly regular mottled effect.


A K Haart said...

We seem to get that when the car is slightly dusty to begin with and when the rainfall is light. This morning the car was wet because of light overnight rainfall, the bodywork being covered in blobs of rainwater. As I drove along the A1, the blobs on the bonnet dried and left a pattern of dusty spots like your photo.

It was as if the blobs of rainwater had absorbed the dust already there then dried to deposit it again as spots.

Bayard said...

AKH, if we assume that the light rain results in the car being momentarily covered with a thin film of water, then surface tension will pull the water up into droplets, carrying the dust with it and leaving clean paintwork between the droplets. When the droplets dry, they leave the dust behind, as you observe.