Where wind comes from...
Differences in temperature, causes differences in pressure. A difference in pressure across distances is called a pressure gradient, and this drives the wind.
Two examples of airflow caused by pressure gradient.
a) When a can of coffee is vacuum packed air is remove from the can, when the can is opened you can hear air rush in from the outside higher pressure. Similarly,
b) When you blow up a balloon you create a high-pressure area because you compress the air and increase its density within the balloon. When the balloon is punctured the air rushes outwards to the lower pressure.
In both examples, air moves from a higher to lower pressure, the greater the difference the faster the air will travel... more...
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Wind is the result of pressure differences in the earth's atmosphere. The wind is caused by the air flowing from an area of high pressure to an area of low pressure, the reason for pressure differences are to do with the rotation of the earth and the heating effect of the sun.
Wind is the movement of air caused by unequal heating of the earth's surface by the sun. The movement of the air is in the form of convection current. When air next to the earth is heater, it expands and becomes lighter. This warmer lighter air is pusher up by the colder, heavier air that surrounds it.
The colder heavier air now is heated and becomes lighter, being pushed up in turn by more cold heavy air that surrounds it. this process continues until there is a steady flow of air, called a convection current, with warm air rising and cold air falling cold air is heavier so it exerts a greater pressure than warm air, so winds are formed when the cold air from high pressure areas moves to low pressure areas where the air is warm.
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How to measure wind
If you can't see the wind, how can you tell how fast it is moving?
Actually, it's very easy. The you can't see the wind, but you can see what it does to other things around you. You know it is windy because you can feel the breeze on your face. You can see the leaves in the trees outside shaking. You can hear the flags waving very loudly.
Let's talk about wind speed. We can describe it in mph. That is the same way we describe how fast the car moves. But instead of looking at the car's speedometer, we will use the natural wind speedometer that is all around us in nature... learn how
Natural wind speedometer
- 1 - 3 mph smoke drifts lazily, branches are still, flags hang limp
- 4 - 7 mph tree's leaves Rustle, flags move slowly
- 8 - 12 mph flags fly, bushes shake, Leaves move
- 13 - 18 mph small branch shake, Grass move
- 19 - 24 mph large branches sway flags flap noisily
- 25 - 31 mph trees shake, dust and sand flies
Kite flying speeds
- 4 - 7 mph Light Breeze. Ideal for single line & large power kites
- 8 - 12 mph Gentle Breeze. Ideal for single line & Stunt kites
- 13 - 18 mph Moderate Breeze. Ideal for smaller power kites
- 16 - 24 mph Fresh Breeze Ideal for power kites, Bugging and boarding
- 24+ mph Strong Breeze. Experienced Flyers Only
The other thing to watch for his wind turbulence. Turbulence is what happens when the wind gets bumpy. And it's is very difficult to fly kite well in bumpy wind!
Think of the wind flowing over the land just like water flowing down a river. If the river is wide with no obstructions the water will flow really smoothly, but if the river has lots of obstacles in the waters way, the water will have to curve around the obstacle affecting the speed and making it rough. The same principal applies to the wind then it comes up against hills, buildings and trees.
Kite fliers have a rule of thumb. We know that wind will be bumpy after going over or around an obstacle .We have measured how long it takes to smooth out, that distance is seven times the height of the obstacle. So if the obstacle is a 30 meter tall, you will need to be 210 metre away from the obstacle to avoid bumpy wind. Otherwise, your kite will be fine for one minuet and falling out of the sky the next. and will usually pick up again in the power zone.
SB Kites is the only kite school in the Dorset coastal area which offers land based power kite lessons, kite buggy lessons and kiteboarding lessons.
Kev and Sue are ready to teach you, your friends and family all aspects of power kiting, bugging and kite boarding enabling you to continue the kiting safely wherever you are. We are experienced kiters with the correct insurance, as well as sports first-aid certificates, and one of our instructors is passed by the criminal records bureau.
Power kiting is a physical sport, so before the lesson, we kit you out with the appropriate safety equipment. We use a range of kites, boards and buggies for our clients and are happy to advise on the kites, boards and buggies that are right for you.
The majority of kite lessons will take place in Poole and Bournemouth, and we choose the best flying days to help you learn to fly! At SBK we can teach you the control of a power kite in one easy lesson - no experience is necessary. There are no minimum fitness requirements, and we tailor each of our courses to suit all abilities.
Contact Kev now, on 07706 445145 and speak to the man who can teach you to fly...