Time: 2 lessons of 50 minutes
Objectives: Students will …
Provide an example of a weather component
Describe how a weather component is measured
Identify weather instruments
Make a simple weather prediction
For each group
Mirror with 100 square grid overlay (made from transparency)
For each student
Lesson 1 Introduction
Go around the circle or room and ask students for their favorite weather or element of weather. Start by giving your favorite as an example. Discuss why it is the favorite – the way it makes you feel, favorite activities, etc.
Obviously, weather affects what humans do - that’s why most of us prefer one type or another. It also affects plants and animals in different ways. Today we’ll be figuring out what weather is, and learning how to take weather measurements and even predict the weather.
1. What is weather?
When I asked you what your favorite weather was, what went through your mind? What is weather?
Weather is the daily state of the atmosphere – what’s happening in the sky. It has several parts: temperature, precipitation, cloud cover, wind speed and direction, air pressure, and humidity. For each of these parts, we use a different instrument to measure it.
We use a thermometer (thermo=heat, meter=measure) to measure the temperature. In the U.S., we use Fahrenheit (o F), but scientifically, the measurement is Celsius (o C).
Demonstrate how to use a thermometer.
We use a rain gauge to measure rain. In the U.S. we use inches. Note: If the diameter of the collection container is the same diameter of the collection tube, then the inch on the tube will equal an inch on a ruler. If the collection area is larger than the diameter of the tube, the inch on the tube will be greater than an inch on a ruler. This is due to the change in area of the container. For example, if you distribute cheerios over a plate in a uniform layer an inch deep, if you pour them into a juice glass, the pile will be higher.
Demonstrate how to use a rain gauge.
Cloud cover refers to the amount of sky that is covered by clouds. This is where the phrases partly cloudy/ partly sunny come from. Demonstrate how to measure cloud cover:
Hold the mirror facing towards the sky, with the grid sheet laid over it. Count how many of the squares are filled with clouds. Convert to %.
Wind speed is measured with an anemometer (anemo=wind, meter=measure). The cups on the anemometer are pushed by the wind. The faster it is blowing, the higher the brace moves up the handle.
Demonstrate how to use the anemometer.
Wind direction can be measured two ways:
A wind vane
Using a compass and a piece of light string tied to a pencil. Hold the compass face up, lined up with N. Place the pencil upright on the compass, and observe which way the string blows.
The barometer measures the local air pressure. The air pressure can help you determine if and how the weather will be changing.
Demonstrate using the barometer.
The sling psychrometer measures the relative humidity – how much moisture the air is holding compared to how much it can hold. It does this by comparing how much moisture evaporates from the wet bulb. If the relative humidity is high, if the air is almost full of water, then not much moisture will be able to leave the wet bulb. If the air is dry (low relative humidity), then a great deal of moisture can move from the wet bulb to the air. As water evaporates from the wet bulb, it cools it off.
Demonstrate how to use a sling psychrometer.
Have students review instruments – what they measure, how to use them.
Review the instruments. Today students will be meteorologists – scientists that study weather.
1. Recording Data
Distribute worksheets to each student. Split the class into groups – each group should have one of each instrument. Have each group take measurements in a different spot outside – in the forest, near the building, in the field. Go over the directions and spaces on the worksheet with them as a class before sending them out to take measurements.
After 10 to 15 minutes, have students return to a central location where you can compare results and discuss. Which things were most variable? Temperature, wind, precipitation might change depending on where you took them. Why?
2. Making Predictions
Use the information gathered to complete the weather forecast area of the worksheet.
Ask students to watch the news in the evening to compare their forecasts with the professional weather person’s.
Meteorologists: Using the instruments provided, please record the current weather conditions for your site.
Site 1 Location:
Air Temperature:o C Wind Direction:
(always named for the direction from which it comes)
Hold the thermometer at arm’s length for 1 minute.
Read the temperature in Celsius degrees _________
Read the temperature in Fahrenheit degrees ________
To what number on your barometer is the black arrow pointing? _________inches
Do not move the gold hand. Is the black arrow above or below the gold hand?
Below The air pressure is falling.
Above The air pressure is rising.
Hold the mirror flat in your hand, facing up so the sky is reflected. How many squares are filled with clouds? _________
Each square equals 1/100 of the mirror.
1/100 = 1%
What is the percent of sky covered in clouds? _________
Put the compass flat on the mirror. Place them at your waist, pointing out from your body. Turn your body until the red pointer is in line with the N on the compass. This means that you are facing North. Which direction are the clouds reflected in the mirror moving? _________
What is the direction across the compass from this direction? _________
Example: North is directly across from South. This is the wind direction.
What is the unit of measurement on your anemometer?
Miles per hour (mph) Meters per second (m/s)
Hold the anemometer Hold the anemometer
away from your body. away from your body.
Record the number to the left Record the number to the left
of the white ball. _________ mph of the top edge of the red bar.
To convert miles per hour to
meters per second, multiply by .45
_______mph x .45 = _______m/s