Deserts & Wind

A dry climate is one in which yearly precipitation is not as great as the loss of water by evaporation

Types of Dry Lands:

• Desert

  • Arid climate, annual precipitation less than 25 cm (10 in)

• Steppes:

  • Semi-arid climate, marginal and more humid variant

  • Transition zone between desert and more humid climates

Arid and semiarid climates cover 30% of Earth’s land surface

Locations:

• Subtropical latitudes

• Mid-latitudes

• Coastal zones

Subtropical deserts and steppes are centered around 20° and 30° N/S latitude.

Climate in these regions is closely tied to major atmospheric circulation patterns.

Mountains across the path of prevailing winds causes a rainshadow.

Coastal deserts:

• Tied to cold ocean currents

• Ex: Atacama Desert, Chile

Ephemeral streams are intermittent and carry water only in response to rainfall events (from the Greek “Ephemeros”, meaning short-lived). Small and dies out before reaching a tributary or the sea.

Playa lakes are ephemeral shallow lakes that form on the basin floor.

Inselbergs:

• Erosion of bedrock and accompanying sedimentation act to lower local relief

Deflation is the lifting and removal of loose material. It can create shallow depressions called blowouts

Loess is a windblown silt deposit