What are the common wind patterns in your area and why?
Introduction: (Initial Observation)
Study on wind speed, direction and pattern is the key to calculate the future position of clouds, hot air or cold air. In this project you will design and build a device to show wind speed and direction. You will then use it to record wind patterns in your area. Finally you study to find the reasons for your local wind pattern and see if wind pattern has any relation with local weather conditions.
You can also record temperature, air pressure and air humidity as parts of weather condition. You may use our own instruments to do these or collect such information from news or the Internet.
Information Gathering:
Find out about wind, how it is produced and the way that it may affect the weather conditions of an area. Read books, magazines or ask professionals who might know in order to learn about different wind patterns. Keep track of where you got your information from.
Wind
Wind is air in motion.
In weather reports or forecasts, wind typically refers only to horizontal motions of air relative to the surface of the earth. However, in everyday usage, the term wind might also be used when referring to instances of rising or sinking air (e.g., updrafts, thermals, downdrafts).
There are four characteristics of wind that can be observed, described, or measured: direction, speed, character (e.g., gusts and squalls), and shifts. Surface winds are measured by wind vanes and anemometers, while upper-level winds are detected through pilot balloons, rawin, or aircraft reports. For additional information about measuring wind, you might also wish to visit the following web sites: http://www.nssl.noaa.gov/~cortinas/1014/l23_1.html and
http://www.usatoday.com/weather/wanemom.htm
Recurring regional winds often have special names.
Wind can have numerous effects.
Wind Speed Records
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For additional information about wind and what causes it, try visiting one or more of the following links:
- USA Today Weather: The What and Why of Wind
- Kids as Global Scientists: Wind Explanation
- Earth and Sky Transcript (March 3, 1997): What Causes Wind?
- Wind: Our Fierce Friend, a curriculum unit by The Franklin Institute Science Museum
- Wind Structure and Characteristics provides an extensive article on the nature of wind and related weather phenomena
- The Danish Wind Turbine Manufacturers Association’s Guided Tour on Wind Energy provides extensive information (and some interesting graphic displays) dealing with wind, wind energy, and wind energy resources
World Climate Systems as Heat Engines
Remember, weather describes localized temperature, wind, and precipitation conditions for a short time. Climate is weather averaged over a long time.
The Sun– Our Energy Source for Weather
Sun is the Earth’s ultimate energy source, and solar radiation is unequally distributed between the Earth’s equator and poles:
This creates a disequilibria between solar heating near the equator and near the poles. As a consequence, there is a temperature differential corresponding to changes in latitude which is forming climate systems, wind and persistent ocean currents.
Hadley Cells
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| Because nature dislikes concentrations of energy, Hadley cells (generically referring to Polar, Ferrel and Hadley cells) which are persistent wind circulation patterns are set up to provide for heat transfer away from equatorial regions. This effect persists all the way to the polar regions. |
(Image sources: http://ess.geology.ufl.edu/ess/Notes/AtmosphericCirculation/atmosphere.html).
Near the equator warm air laden with mixed with vapor rises through the atmosphere (ascends) at fairly slow rates. As the air rises it cools, as it cools it loses the capacity to carry water vapor. Vapor condenses into clouds, releasing energy to the system (the latent heat of evaporation in reverse).
Because air is, in general, convecting near the equator under the rising branch of the Hadely cell, convective storms form easily there. Near +/-30 degrees latitude the subsiding branches of Hadley cells return cool, dry air to the Earth’s surface. Convective storms are suppressed at these latitudes and as the cool air descends it warms. Cloud formation at these latitudes is also suppressed– the cool, dry air warms as it descends and condensation is inhibited.
The Earth’s rotation causes a deflection of the winds comprising Hadley cells, setting up persistent wind patterns, for example the trade winds and the furious forties.
(Some of this information was derived from the excellent web page “Why are deserts dry?”, Milich, L., 1997. http://ag.arizona.edu/~lmilich/dry.html.)
Climate Systems are really Energy Equilibrators
The Hadley cells set up by the uneven, latitudally-dependant influx of solar radiation is really just a grand conspiracy by the Earth to distribute energy evenly across its surface. Many cyclical processes identified in nature serve the same purpose. Just as nature dislikes vacuum, so does it dislike concentrated energy.
Heat Engines are Invading!
Let’s think about Hadley cells and climate systems in terms of our description of a heat engine.
1) The Hadley heat engine uses a latitudally-variable temperature difference to do work.
2) It does work on water from the oceans. Once the water has evaporated, the heat input goes towards lifting water vapor higher into the atmosphere. This is how clouds form.
3) The Hadley heat engine is cyclical in nature.
- Water vapor is formed when solar radiation is converted by oceans into an increase in internal energy. Buildup of water vapor over the oceans constitutes loading of the heat engine.
- The water is lifted to higher elevations, along with the warmed air. This is the “power stroke” of the heat engine.
- At sufficient altitude, the water vapor begins to condense into clouds. This is the unloading of the heat engine. Heat energy is transferred into the surrounding air during this process.
- At the equator, the air moves either northward or southward at the top of the troposphere, moves through the Hadley cycle path and, eventually, returns to the starting point, over the oceans at the equator, for example.
4) Energy is conserved in the entire, closed system, which includes the oceans and the atmosphere.
5) Inefficiencies result in a certain amount of heat energy being transferred to the atmosphere and the oceans further away from the equator.
In fact, the “work” performed by our Hadley cell heat engine goes towards cloud formation and the start of the hydrological cycle.
How else is heat energy transferred through our climate?
Persistent ocean currents also serve to transfer heat energy away from the equator, and these currents have a profound impact on climate:
{graphic courtesy of: http://www.gcrio.org/gwcc/booklet1.html}
Even though it sometimes seems like the atmosphere tries harder, the oceans are more successful at transferring heat energy away from equatorial latitudes.
Question/ Purpose (Wind Project):
The purpose of this project is to see what are the common wind patterns in our area and why?
In this project, you may also compare wind direction (and speed) in different hours of the day in your area.
Identify Variables:
(Not required for this project)
When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other.
variables that affect the wind speed and direction are the temperature difference between two areas as well as the rotation of the earth. However in this project we are not going to study these variables. Instead we will attempt to see if there is any relation between the wind direction and changes of the weather condition.
For example we may discover that if the wind is blowing in a certain direction, that is an indication of certain weather conditions in the next few hours or the next few days.
Hypothesis:
(Not required for this project)
Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis. A sample hypothesis is as follows.
The persistent air current in our area (New Jersey) is in the south east direction. However when the wind blows in the north east direction, that is an indication of up coming warm air and temperature increase.
Since most weather conditions can not be experimented in the lab, we are going to research this by gathering statistical information.
If you have enough time, you may record the wind direction and weather conditions yourself, otherwise you may gather pre recorded information from local newspapers or the internet. We used the following two website for gathering information about wind direction in new jersey. To find these web sites we used the search term “Wind direction in New Jersey”.
Experiment Design For Wind Project:
Design an experiment or tool to measure wind speed and direction. Make a step-by-step list of what you will do. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a “control.” A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral “reference point” for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a “controlled experiment.”
Measuring Wind Speed
Purpose
To measure wind speed with minimal equipment and surprising accuracy.
Equipment
- strong thread or thin fishing line – about 40 cm long
- ping-pong ball
- large protractor
- glue and tape
- thick cardboard (for mounting protractor)
Procedure
- Mount the protractor with tape to the cardboard, curved side pointing down.
- Tape or glue the thread to the ping-pong ball.
- Tie or glue the other end of the thread to the center of the protractor.
- When the wind blows the thread off center, read the angle on the protractor
- Convert this angle to the wind velocity in this table.
- Use your instrument outside and away from buildings to measure wind speed. At the same time, use the Beaufort wind scale to write down your observations about the strength of the wind.
String Angle (degrees) 9080706050403020Wind Speed (km/h) 013192429344152
Questions
Answer the following questions in the spaces provided.
- What is wind?
- Can wind be useful to us?
- What damage can wind do?
- Does your instrument give a measurement of wind speed that agrees with the measurement using your observations and the Beaufort wind scale? Can you suggest any improvements to the instrument?
Beaufort Wind Scale
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Beaufort Number
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Description | Wind Speed (km/h) | Effect |
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0
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Calm | Less than 2 | Smoke Rises Vertically |
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1
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Light Air | 2-5 | Smoke drift shows wind direction, wind vanes don’t move |
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2
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Light Breeze | 6-12 | Wind felt on face, wind vanes move |
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3
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Gentle Breeze | 13-20 | Leaves and small twigs in motion, hair disturbed, clothing flaps |
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4
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Moderate Breeze | 21-30 | Dust and loose paper moved, small branches move. |
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5
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Fresh Breeze | 31-40 | Small trees with leaves begin to sway, wind force felt on body. |
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6
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Strong Breeze | 41-51 | Large branches move, umbrellas difficult to use, difficult to walk steady. |
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7
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Moderate Gale | 52-63 | Whole trees in motion, inconvenience felt when walking |
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8
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Gale | 64-77 | Twigs broken off trees, difficult to walk |
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9
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Strong Gale | 78-86 | People blown over, slight structural damage including tiles being blown off houses. |
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10
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Whole Gale | 88-101 | Trees uprooted, considerable structural damage. |
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11
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Storm | 102-120 | Widespread damage. |
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12
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Hurricane | Greater than 120 | Widespread devastation. |
Explanation
Heat from the sun warms the air and makes it rise. This occurs mainly in tropical regions, near the equator, where the sun’s energy is most intense. As warm air rises, cool air rushes in to take its place. We feel this movement of air as wind.
During the day in summer, land is generally warmer than the sea. This temperature difference can set up cooling daytime sea breezes, which can penetrate many kilometers inland. At night, breezes may blow in the opposite direction, from the land to the sea.
Similar daily changes in temperature occur over irregular terrain and cause mountain and valley breezes. Other winds induced by local phenomena include whirlwinds and winds associated with thunderstorms.
Extension Activity
Can you devise another simple instrument for measuring wind speed?
Fact File
The strongest wind ever reliably measured on the surface of the Earth was 362 km/hr, recorded on Mt. Washington in the United States on 12 April, 1934. Much stronger winds, however, occur near the center of tropical cyclones.
Experiment 1:
Building a Wind Vane that you can use to observe and record the wind direction.
Background
A wind vane is really just a flat piece of metal or wood on a swivel that catches the wind and points toward and away from the wind. You have probably seen pictures of a wind vane on top of a barn. It is usually shaped like a farm animal such as a horse or a rooster. It usually has an arrow to point in the direction the wind is blowing. However, wind is described in terms of where it is blowing from. For example, a west wind blows east.
Materials
- 3 ft x 3 ft piece of thin wood or plastic
- bicycle wheel or skate wheel or lazy susan
- saw
- screws
- plastic or metal letters, “N, E, W, S”
- sand paper or file
Procedure
Read all Precautions before beginning this activity.
- Cut an interesting shape from wood or plastic. Be sure to include a pointer. Round all edges except the bottom.
- Mount the shape to your chosen swivel.
- Install your wind vane on top of a tall pole or on the roof of a shed or house.
- Keep a log of the wind direction as observed several times a day.
Precautions
- It is important you build these weather instruments while under the direct supervision of an adult who has knowledge of safety precautions related to all materials listed.
- Care must be taken when working with power tools, fire, heat-generating electrical devices, hand tools, sharp objects and other tools. Do not use these devices unless there is an adult present to supervise.
- Cutting plastic soda bottles can leave sharp and pointed edges. Be sure to file or sand any cut edges immediately after cutting.
- An adult must install devices that require a ladder to access installation areas.
- Do not attempt to access your weather station during storms.
Experiment 2:
Does the speed and direction of wind affect the weather condition?
Materials:
- Wind Vane
- Thermometer
- Clock
- Notebook
Procedure:
- Mount your wind vane and thermometer somewhere outside where you can observe the wind direction and weather temperature.
- Decide about your observation times and make a note of it. (For example 7:00 a.m, 1:00 p.m. and 6:00 p.m)
- Every day on on your observation time observe the wind direction using your wind vane and record it in your log book or your results table.
- Every day on your observation time also see a thermometer and record the temperature.
- Every day on your observation time record the cloud condition.
- Every day on your observation time record the wind power or speed using the Beaufort Wind Scale (available above)
- Record your results in a table like this:
Date Time Wind Scale Wind Direction Temperature Cloud
Review and analyze (logical thinking) and look for repeated patterns. Do you see any relation between the wind direction and the weather temperature?
Materials and Equipment:
List of material can be extracted from the experiment section.
Results of Experiment (Observation):
Experiments are often done in series. A series of experiments can be done by changing one variable a different amount each time. A series of experiments is made up of separate experimental “runs.” During each run you make a measurement of how much the variable affected the system under study. For each run, a different amount of change in the variable is used. This produces a different amount of response in the system. You measure this response, or record data, in a table for this purpose. This is considered “raw data” since it has not been processed or interpreted yet. When raw data gets processed mathematically, for example, it becomes results.
Calculations:
Description
Summary of Results:
Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.
It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.
Conclusion:
Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did.
Related Questions & Answers:
What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.
Possible Errors:
If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.
If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.
References:
Visit your local library and find books related to meteorology and winds. Review and list such books as your references in addition to this website and other Internet resources you may use.
Notes:
Anemometer
The anemometer is used for measuring the wind speed. It measures the speed by spinning in the wind. It can be made of three or four plastic cups, a block of wood, an eye dropper, a nail and a cork.
First we sanded the wood. Then we colored the top with markers. We put a nail through the bottom and put an eye dropper on it. We got three nails and stuck the medicine cups through them. Then we stuck the nails into a half cork and colored one cup with a marker. We stuck the cork on the eye dropper. We took it outside. Then you can count how many times it goes around in a minute. Ten turns was about one mile per hour.
Another Design for an anemometer
Material:
- Thin sheets of aluminum (cardboard)
- Dowel stock
- 2 glass beads
- 2 thin wooden sticks, 18 inches x 1/2 inch
- Aluminum solder
- Nail
Procedure:
- The anemometer cups are made from the aluminum. Cut 2 circles about 4 inches in diameter.
- Cut the circles in half along the diagonal
- Join the straight edges with aluminum solder, making 4 small cups
- Attach the cups to 2 crossed sticks, so that all are heading in the same direction
- Join sticks to dowel stock as follows: Nail, glass bead, crossed sticks, glass bead, dowel stock. The glass beads will act as bearings so the wind will turn the anemometer freely.
NOTE: The anemometer will spin faster as the force of the wind increases.
Weather Vanes
The weather vane tells you what direction the wind is blowing. First we took a piece of wood, drew diagonal lines to find the center and hammered a nail in the middle. Then we colored it with four colors. We put north, south, east and west on each side. We stuck a pen cap on the nail and stuck a cork onto the pen cap. We took a feather and hot glued it on the cork. We took them outside and held it up as high as we could to see which way the feather is pointing. If it is pointing to the east, it means the wind is coming from the east.
This picture shows a home made anemometer and a weather vane.
Barometer
The barometer is a nice forecasting tool. It shows air pressure. If the pressure is going up that means we’re going to have good weather, but if the pressure is going down that means we’re going to have bad weather. We made the barometers by putting a balloon over the top of a jar and we smoothed the balloon out. After that we put a rubber band over the balloon. Then we cut the end of a straw diagonally so it had a point and taped it on the balloon. Finally, we rolled up a big ball of clay and stuck it to a flat surface. We took a ruler and stuck it through the clay. When it is made, the straw will go up and down each day to show the pressure.
Rain Gauges
The rain gauge is something that measures the rain. It gets water in it. We made it with a big plastic soda bottle, tape, hot glue, a plastic plate, tape, and a ruler made on overhead material. First we cut the top off the two litter bottle and then taped them together with the top inside. Then hot glue on the measuring stick on the outside with hot glue. Then hot glue it to a plate. When it rain the water goes inside and you can see how much water is in it.
