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The Word on the Weather

Wind Flow

As we look at satellite pictures it is easy to distinguish the continuous circular movement of cloud masses. This circular movement of weather patterns is caused by the rotation of our planet. At the equator the earth spins at 1,670 kph, at the poles however, the earth has no rotational speed at all. The best way to explain this phenomenon is to consider a merry-go-round. If you were to throw a ball from somewhere near the centre of the merry-go-round an observer would see the ball appear to follow a curved path, on earth the moving air displays a similar deflection. Since the globe is rotating, any movement in the Southern hemisphere is diverted to the left, if we look at it from our own position on the ground. (In the Northern hemisphere it is diverted to the right). This apparent bending force is known as the Coriolis force. (Named after the French mathematician Gustave Gaspard Coriolis 1792-1843). The Coriolis force is a visible phenomenon. Railroad tracks wear out faster on one side than the other. Riverbeds are dug deeper on one side than the other. (Which side depends on which hemisphere we are in: In the Southern hemisphere moving particles are bent towards the left). In the Southern hemisphere the wind tends to rotate clockwise (as seen from above) as it approaches a low-pressure area. In the Northern hemisphere the wind rotates counter clockwise around low-pressure areas. The wind rises from the equator and moves north and south in the higher layers of the atmosphere. Around 30 latitude in both hemispheres the Coriolis force prevents the air from moving much further, at this latitude there is a high pressure area as the air begins sinking down again. As the wind rises from the equator there will be a low pressure area close to ground level attracting winds from the North and South. At the Poles, there will be high pressure due to the cooling of air. Keeping in mind the bending force of the Coriolis force, we thus have the following general results for the prevailing wind direction:
Prevailing Wind Directions 
Latitude:  90-60N     60-30N     30-0N     0-30S     30-60S     60-90S
Direction:    NE           SW           NE          SE          NW            SE
Job 37:11-12 He loads the clouds with moisture; He scatters His lightning through them. At His direction they swirl around over the face of the whole earth to do whatever He commands them.

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