Dear Tom,
It is the middle of the winter now, and my mind drifts back to our family trip across Death Valley last summer. The temperature there was 121 degrees when we drove across the valley. What causes such heat?
— Jerold Krasvic
Dear Jerold,
Death Valley is routinely scorched by heat resulting from several atmospheric and geographic factors working in concert: latitude, elevation, parched air, sunshine, rocky soil, surrounding lofty mountains and a lack of vegetation.
Death Valley lies south of rain-bearing midlatitude storm systems and north of rainy tropical systems. Air bound for the valley loses its moisture as it passes over the mountains, after which it falls several thousand feet, compressing and warming as it nears the valley, which lies about 180 feet below sea level.
This ensures dry, sunny climate on the valley floor. Rocky soil absorbs the heat of sunlight and transfers it to the air.
Finally, there is no vegetation to moisten the air, so it warms more.
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