Where does the wind come from?
what does atmospheric pressure show us;
that pressure changes signal a change in the weather;
how to use a barometer.
explain how wind is formed;
explain how and why the air temperature changes over a 24‑hour period;
build a simple anemometer and use it to determine the direction and strength of the wind.
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How is wind created?
Let's check if heating the air affects its movement.
Checking how temperature change affects air movement.
scissors,
card,
twine,
needle,
candle.
Draw a spiral on the card and cut it out.
Use the needle to pierce the center of the spiral, and pull the string through the hole.
Light the candle.
Grab the thread and place the spiral over the candle. What did you observe?
If the spiral begins to rotate, it means something must have set it in motion. This is due to the heating of the air. As a result, there are temperature differences. The warmer air rises, and is replaced with cooler air.
The sun's rays first heat the Earths surface, and the air then heats up from it. This happens unevenly:
rocks get hot faster than forest or water;
dark surfaces warm up faster than light ones;
the water warms up slower than land, but stays warmer for longer.
The uneven heating of the Earth's surface causes temperature differences. Thanks to this, there are changes in atmospheric pressureatmospheric pressure. Warm air exerts on the different atmospheric pressure than the cool air.
Clouds have a big influence on air temperature. During the day they limit sunlight, and at night they stop the heat escaping. That is why during certain times of year cloudy nights are warm compared to clear nights, and cloudy days are cooler than those when the sky is clear. The temperature also depends on the height of the Sun above the horizon – therefore it is warmer in the summer than in the winter, and it is warmer in tropical countries than in Poland.
In places where the air rises, air pressure decreases slightly, and where it falls – it grows. Thus, the air flow happens from a place of higher pressure to a place with lower pressure .Such horizontal air flow is called windwind. If we want to describe the wind, we should give its direction and speed.
Before you do the „Creation of Wind experiment, write down the research question and the hypothesis. Then follow the attached instruction. Make observations during the task, and finally - conclusions.
Wind direction and speed
Knowing the areas with high and low pressure, and remembering that the wind always blows from high to low, you can predict in which direction it will blow. It is important to remember that giving the direction of the wind, we name it from which way it blows. For example, if the wind blows from west to east, it is a westerly wind. If it is different from the main directions (N, E, S, W), you can include more specific directions: NE – North East, NW – North West , SE – South East and SW – South West.
The stronger the wind the greater the pressure difference between two places. A device called anemometeranemometer is used to measure wind direction and speed.
Building a simple anemometer and determine the wind speed and direction.
stick,
drawing pin,
ribbon,
compass,
chalk.
Find a stick with a length of approx. 1 m.
At the end of the stick, attach a ribbon with a length slightly shorter than the stick.
Outside, in an open area, set the stick by hammering it into the ground around 10 -15 cm.
Draw lines that mark (N,E,S,W) from the pole, using a compass. Remember to mark them.
Observe the end of the ribbon: which side is leaning out and how high it rises.
1. Ribbon blowing in a specific direction shows us which way the wind is blowing. Thanks to this, we can determine the wind direction. It should be remembered that to name the direction, we say from which way the wind blows.
2. The distance of the ribbon from the stick allows us to roughly estimate whether the wind speed is high or low.
Match the pairs: English words with Polish definition.
poziomy ruch powietrza wymuszony różnicą ciśnienia atmosferycznego, spowodowaną zmiennym nagrzewaniem się powietrza nad różnymi obszarami, przyrząd służący do pomiaru kierunku i prędkości wiatru, ciśnienie atmosferyczne informuje nas, jaki nacisk wywiera powietrze na jednostkę powierzchni ciała (np. 1m2); jednostką miary ciśnienia jest paskal (1Pa); powszechnie używana jest też jednostka 100 razy większa --- hektopaskal (1hPa = 100Pa)
| wind | |
| anemometer | |
| atmospheric pressure |
Summary
Wind is the level of air movement caused by a difference in atmospheric pressure.
The stronger the wind, the greater the difference in atmospheric pressure.
By giving the direction of the wind, we determine where it is blowing.
The wind can be used as propulsion for sailing vessels and wind turbines.
Keywords
atmospheric pressure, wind, anemometer
Glossary
wiatr – poziomy ruch powietrza wymuszony różnicą ciśnienia atmosferycznego, spowodowaną zmiennym nagrzewaniem się powietrza nad różnymi obszarami
wiatromierz – przyrząd służący do pomiaru kierunku i prędkości wiatru
ciśnienie atmosferyczne – ciśnienie atmosferyczne informuje nas, jaki nacisk wywiera powietrze na jednostkę powierzchni ciała (np. 1m2); jednostką miary ciśnienia jest paskal (1Pa); powszechnie używana jest też jednostka 100 razy większa – hektopaskal (1hPa = 100Pa)