Wind Creation

Wind is a constant.  Wind moves all the time.  Sometimes it moves fast and sometimes slow.  It depends on the atmosphere and the sun above.

The sun warms the air.  That warm air rises, the cold air sinks – creating wind.  The weather guys call this feud between warm and cold air fronts.  High pressure comes in on a warm front that moves about 15 miles per hour.   Low pressure follows a cold front.  They move at 30 miles an hour or so.  Wind always moves from high pressure to low.

 
The earth’s surface creates friction with wind and the friction slows the wind down.  Prairies, deserts, and parking lots don’t create as much friction as forests, mountains, and buildings.  Mountains and high rise buildings cause wind to move up but otherwise wind moves horizontally across the earth.

Cities do funny things to wind.  The buildings and asphalt collects heat from the sun during the day.  The city releases that heat slowly at night or on a cloudy day, creating thermals or updrafts of wind.  Birds love soaring on thermals.  Watch them.

Wind can also carry things.  Dust from Africa can be the basis for a snowflake in Wisconsin.  Wind can be damaging, too.  Straight line or tornado or hurricane-force all wreaking havoc on the things humans build.  It’s important to know what’s coming so you can get out of its way.

Pack out what you pack in.

 

Sources:
            Catch the Wind Harness the Sun by Micheal J. Laduto, Storey Publishing, © 2011
            Weather! By Deborah Burns, Storey Publishing, © 2003
            The Kids book of Clouds and Sky by Frank Staub, Sterling Publishing, New York, NY, © 2003