ARTICLE INDEX:
SUMMARY
The source of the wind is the sun. The winds come from the suns energy falling on the earth's surface. This will last as long as the sun continues, and so is renewable for practical purposes into the distant future. This leads to convection currents in the atmosphere, ie the movement of air due to changes in its density and pressure. We can gain an understanding of how global circulation works by developing two simplified models of processes that produce this system.
Drivers of the wind at a global scale are examined; gravitational force, pressure gradient force, coriolis force , centrifugal force, friction force Drivers of the wind at a small scale are also examined.
Sources giving estimates of the total quantity of wind energy available for electricity generation are reviewed, and compared with current electricity demand for the globe and for major regions.
INTRODUCTION
The source of the wind is the sun. The winds come from the suns energy falling on the earth's surface. This will last as long as the sun continues, and so is renewable for practical purposes into the distant future. Due to the orientation of the earth's surface to the sun's rays near the equator the rays strike the surface at more optimum angles. The effect is that the air near the surface in tropical regions is heated more than the air near the surface of the polar regions. This leads to convection currents in the atmosphere, ie the movement of air due to changes in its density and pressure. This air movement is the principal cause of the winds.
For descriptive and analytic purposes the atmosphere is commonly divided up into the following scales:
| Planetary |
>3,000km |
| Synoptic |
300 to 3,000km |
| Mesoscale |
2 to 300km |
| Microscale |
2mm to 2km |
>>> (Page 2) - Global Scale Circulation of the Atmosphere - A Simple Model of Global Circulation |
