One of the most important, but often overlooked, aspects of the world around us is the weather. It has an impact on everything in our lives – from what we wear day to day, to whether or not we are able to eat!
So what is it, really?
Weather is the condition of the atmosphere at a certain time and place. It is affected by the amount of wind, moisture, pressure and temperature in the air.
In order to fully understand weather, we need to be able to understand wind.
Wind is, very simply, moving air. It is also one of the driving factors of weather – it causes and carries weather phenomena from place to place.
What causes wind?
Wind is caused by the uneven heating and cooling of the earth’s surface - both globally and locally.
For instance:
As solar energy reaches the Earth, areas around the equator heat up more than the poles. Air in this region expands as it warms, creating areas of low air pressure, which rise. The warmer the temperature of air, the lower the pressure.
Air around the poles receives less solar radiation, and are cooler than air around the poles. These regions of cooler air condense, sink and create areas of high air pressure. The cooler the temperature of air, the higher the air pressure.
Wind is created by the convection that occurs as a result: low pressure (warmer) air rises; High pressure (cooler) air sinks, and rushes in to fill the space left by the rising low pressure air.
So our definition of wind, then, can be changed to: air moving from areas of high pressure to areas of low pressure.
Incidentally, the greater the difference in pressure (and temp) between two pockets of air, the higher the force/speed of wind.
