Presentation on theme: "Why are Deserts so dry? SAHARA DESERT in North Africa Key places today… North Africa Sahara Desert Atlantic Ocean Canary Islands Morocco Atlas Mountains."— Presentation transcript:
Why are Deserts so dry?
SAHARA DESERT in North Africa Key places today… North Africa Sahara Desert Atlantic Ocean Canary Islands Morocco Atlas Mountains
High PRESSURE or anticyclone Air sinks Air warms Moisture evaporates Clear blue skies and dry weather Deserts are areas of permanent HIGH PRESSURE 1.
Deserts lie on the West side of continents…. In zones where the prevailing winds come from the east. 2.
Saharan sand blown off to the west by easterly winds.
The cold ocean current : THE CANARY CURRENT 3.
Canary Islands - fog
It was pretty cold and windy in the damp fog
San Francisco coast California – Also gets fogs.
Moisture condenses out of the air over cold oceans 3.
RELIEF RAINFALL and RAIN SHADOW Atlantic OceanAtlas MountainsSahara Desert
RAIN in Morocco Sahara Desert Rain near Equator
Rain Shadow effect here Sahara Desert Begins Relief Rainfall Here
Warm dry air sinks down into the Sahara… … making it a desert
The Relief Rainfall and the Rain Shadow happens in the dry SW USA too.