esrosedotblog

YOU VEE

Now, class; this is climatology part two.

Yesterday, we discussed the rain shadow; why it is so dry here. There is another consideration that I did not high light (so to speak).

Remember what we said about the high mountain; how it affects us?

Yes! The desert is fundamentally dry because we live in a rain shadow. The clouds require enough moisture, lift, and force to get over the biiiiiig high mountains. Mostly, they hang on the other side and drop most of their moisture before coming over to us.

But, wait! There is something else going on!

To make it even harder for the wet air to get here, we have an updraft of hot dry air that comes off the desert floor. That stops any stray moisture that gets over the top; on a good day you can see the hot air 'eating' the clouds. As a result, the moisture, lift and force have to be even greater to combat this thermal effect.

Ironically, the hot draft is a result of the dryness created by the rain shadow in the first place.

Hey! Are you paying attention to this?

Wake up goddamit!

Where was I? Oh. Rain shadow. Dry. Heat. A cycle is set up. When the desert air is dry, the sun's ultraviolet rays beat through the protection of the atmosphere and smack into the also dry soil of the desert floor. There ain't no water in the soil to absorb the heat by making steam (humidity) and so the uv energy is transformed into infra red energy. Now that range of the spectrum is heat. Sure, you can feel the sun with the ultra violet and you can get a bad sunburn if you don't use a PSF 40 or something. But the IR is the hot side of the light spectrum. What your stove puts out.

We can feel the heat rising off the surface. It gets so friggin' hot on the sand you could cook an egg. Or your feet, if you are dumbass enough to go barefoot.

This is why, as soon as the sun goes down, we get a 30 degree drop in the ambient (look it up) temperature. No moisture. Nowhere. Not in the ground, not in the air. Take a bottle of water with you, pardner, or there won't be any water in you either.

OK, let's wrap this shit up. The dryness is self perpetuating, in that the thermals make it even harder to rain on our parade.

The uv is so important to the effect that, in fall and winter, when the sun starts to come in at a steeper angle and the days get shorter, it is easier for the wet weather to get over.

I am getting so done with this. Let's take a break. I am thirsty.