Many thousands of years ago, the Sahara was a green home to water-loving animals, like hippos. Then the climate changed. Today rising and falling winds pull moisture away from the desert, but they rarely bring rain.

A wind by any other name...

Many of the Sahara's winds have special names:

Haboob is the Arabic name for a wild, sand-laden wind.

Khamsin, also Arabic, means "50 days." This wind sweeps across the desert from March through May, filling the air with sand.

The name of the desert wind harmattan comes from a word in the West African language Twi that means "to tear your breath apart."

Image of hippos from University of Pennsylvania Multimedia database.