Rain shadow

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Rain shadow is a dry area on the mountainside facing away from the direction of the wind. The mountains block the passage of rain-producing weather systems, casting a "shadow" of dryness behind them.
Rain shadow is a dry area on the mountainside facing away from the direction of the wind. The mountains block the passage of rain-producing weather systems, casting a "shadow" of dryness behind them.

Rain shadow is a dry area on the mountainside facing away from the direction of the wind. The mountains block the passage of rain-producing weather systems, casting a "shadow" of dryness behind them.

The condition exists because as warm moist air rises through "orographic lifting" to the top of a mountain range or large mountain, where due to decreasing atmospheric pressure with increasing altitude, it has expanded and adiabatically cooled to the point that the air reaches its dew point. At the dew point, moisture condenses onto the mountain and it precipitates on the top and windward sides of the mountain. The air descends on the leeward side, but due to the process of precipitation, it has lost much of its initial moisture.

Typically, descending air also gets warmer (see Foehn winds) down the leeward side of the mountain, creating an arid region.

[edit] Also See

[edit] Reference

  1. Wikipedia Rain shadow [1]

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