Global Winds

Global Winds by Arianna Valdes :)

Global winds are a very complex thing to get a grasp the concept of. They are formed by unequal heating on the earth. The most direct sunlight in on the equator and the least direct sunlight in on the poles of the earth. So therefore the equator has low pressure and is less dense and the poles a have more high pressure and is more dense. So because of the unequal heating and convection currents form. Also there are wind belts called the trade winds, the prevailing winds and the polar easterlies. The wind belts are the winds that basically separate the convection currents from each other. The trade winds start off in the equator and go to 30 degrees north and south.The prevailing winds are wind move from 30 degrees north and south and move to 60 degrees north and south. Finally the polar easterlies move from 60 degrees north and south to 90 degrees north and south (which are to the poles). Also there is an area called the doldrums were the warm air rises from the equator, it is a very calm area around the globe. There would be no curving belts if the earth didn’t rotate though. It would be very straight and boring.

http://deckskills.org/sitebuildercontent/sitebuilderpictures/global_wind_diagram.jpg

You may have heard the phrase Coriolis Effect before but never knew what it meant or was. Well, hopefully my summary clears up any confusion for you guys. It is the effect that makes the wind blow over the Earth in a certain direction. So the reasoning why, is when you are flying you can’t just move in a straight line, because of the rotation of the earth. This is because the earth is rotating while you are flying, so you need to plan your flight with the Coriolis effect. In the northern hemisphere the path moves right from where the wind comes from and in the southern hemisphere the path moves towards the left from where the wind comes from. 

http://www.pinellascounty.org/newsletters/e-lert/images/feb_2010/coriolis-effect.jpg

On a cylinder the side of it all has equal heating from the sun which causes low pressure through-out the sides and high pressure at the top and bottom. In the center the low pressure warm air rises up and up towards the top and once it reaches the top the air sinks because the air gets cooler and has more density and circles back to the middle. The same thing happens in the southern hemisphere just reversed. The cool air sinks and the warm air rises back to the middle. So there are 2 convection currents being formed on a cylinder because of the unequal heating on the top and bottom. So a cylinder shape is close to the earth but there are some major differences. 
  

A cube unequal heating on the top and bottom. It is sort of like the cylinder but it is a little different. The top and the bottom have high pressure and cool air and the other 4 sides have low pressure and warm heating. Also the winds blow towards each other while they are spinning. There is one big blob of a convection current circling around the cube hitting all the sides.

On a pyramid is a little more complex than the rest though. At the top of it is just a single point so there is really no effect on that. But along the side of the pyramid there is equal heating and direct heating which leads to warm air and low pressure. The bottom of the pyramid is flat and has cool air and high pressure. Since there is only one unequal heating source the warm air moves towards the bottom were the unequal heating is and then slides over the pyramid and goes back to the being. So it is one big convection current. This one is probably farthest away from the shape of the earth.   

Here is a good video to help you guys deeper understand global winds.

http://www.youtube.com/watch?v=mi6F1PdXUPM