2 - The atmospheric dynamics of deserts

Summary

The Bedouin of the desert, born and grown up in it, had embraced with all his soul this nakedness too harsh for volunteers, for the reason, felt but inarticulate, that there he found himself indubitably free. He lost material ties, comforts, all superfluities and other complications to achieve a personal liberty which haunted starvation and death.

T. E. Lawrence, British writer and adventurer Seven Pillars of Wisdom (1926)

And it is an almost terrifying magnificence … In a distance that is much clearer than usual earthly distances, mountain chains join and overlap. They are in regular arrangements that man has not interfered with since the creation of the world. And they have harsh brittle edges, never softened by the least vegetation. The closest row of mountains is a reddish brown; then, as they stand closer to the horizon, the mountains go through elegant violet, turning a deeper and deeper blue, until they are pure indigo in the farthest chain. And everything is empty, silent, and dead. Here you have the splendor of fixed perspectives, without the ephemeral attractions of forests, greeneries, and grasslands; it is also the splendor of almost eternal stuff, freed of life's instabilities. The geological splendor from before the Creation. …

Julien Viaud, French writer, soldier, painter, and acrobat Le Désert (1895)

Because discussions in this chapter, and others in later chapters, will employ many concepts in basic atmospheric dynamics, the first section below will present some essential background review material.