Why is it always windy at the top of a mountain?
Natural Phenomenon Friday #1
Even on still, sunny days you will find wind on a mountain peak. If you stand on top of a steep mountain slope or a cliff and lean over the edge you will get a faceful of wind moving up the slope. It’s called an anabatic wind, from the Greek anabatos, which means “moving upward.” We all know that hot air rises, which is easy enough to grasp if you’ve ever been in a house with a warm upstairs but a perpetually chilly basement. Outside in nature, air temperature is affected by many variables, including the surface temperature of the ground.
Anabatic wind works like this—imagine two mountains next to each other, with a valley in between. The sun heats the slope of the mountain and the air directly above it. The air above the surface of the ground heats more quickly than the air that is suspended over the adjacent valley. The hotter the air, the less dense it is, which causes it to begin to move upward toward the mountain peak. When the hot air rises, cooler, denser air then replaces it, creating an air current or an upward moving anabatic wind. So when you stand at the top of the mountain you feel and hear a near constant upcurrent of wind.
Next time you hike a mountain you can tell your friends all about it. A lot of things sound more interesting when you are out of cell service with no other options for entertainment—it’s the perfect captive audience.
Love the short little explainer! I’ll definitely be parroting this to the person next to me on my next hike.