This Scotland Outdoors podcast from BBC Radio Scotland.

Hello and thanks very much for choosing to listen to this.

As I stand here in the car park in BBC Aberdeen, I'm looking up at two layers of cloud at the moment.

Very, very high.

There's thin cloud which doesn't seem to be moving at all.

And then fairly low to the ground, I'd say maybe 2,000,000 feet.

There is grey cloud, which is fairly scudding past.

It's obviously two different systems.

I find clouds fascinating.

And recently, I went down to Glasgow to meet up with a man called Dr. Edward Graham, also known as Eddie the Weather.

He's just published his first book, Clouds, which not only describes the scientific aspects of cloud development and formation and the fact you can weigh the things, which is unusual.

But interestingly, he looks at it from the perspective of famous artists who have also painted clouds, included them in their work,

from a scientific viewpoint, as well as a story of physicists

and even an explanation of how clouds are named.

We started off looking up.

Righto, it's a bit hazy today, isn't it?

It's got this kind of pale, sort of greyish haze, don't we?

And nearer to us are these fluffy cumulus clouds.

So these are buoyant, fairly low-level clouds.

But these are cumulus humulus, and cumulus fractus.

So cumulus are cotton wool clouds formed by daytime convection,

that is when the sun heats the ground, the air rises in little thermals, and then it turns over

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