Question

What is the 'rain shadow effect' and how does it contribute to desert formation?

1. The rain shadow effect occurs when mountains block moisture-laden winds from reaching the leeward side.
2. As winds rise over mountains, they cool and release precipitation on the windward side, leaving the leeward side dry.
3. The Sonoran Desert in North America is an example of a desert formed primarily by the rain shadow effect.
4. The rain shadow effect is caused by cold ocean currents.

• A. 3 only
• B. 1, 2, 3
• C. 1 only
• D. All

Answer 1

Answer:

B. 1, 2, 3

• The largest hot deserts, like the Sahara and Arabian deserts, are located in the trade wind belt near the sub-tropical high pressure belts in both the hemispheres.

• These are places located under the descending limb of the Hadley Cell that dominates the at-mospheric circulation in tropical areas.

• As the air subsides, it warms adiabatically, in-hibiting condensation and precipitation.

• Some deserts are located on the leeward side of mountains and the rain shadow effect is re-sponsible for their formation.

• The Sonoran desert in North America is located to the east of the coastal ranges.

• While moisture bearing winds arising from the ocean bring precipitation to the western flanks of the ranges, places to the east receive no pre-cipitation from them as they have already shed their moisture before reaching here.