Grade 4 Science

Core Unit: Predicting Weather

1. Interpret information on weather maps.
2. Forecast weather based on cloud patterns.
3. Interpret recorded data.
4. Predict weather based on a number of different indicators.

1. Suggest some reasons why people rely on accurate weather information.
2. Explain the importance of good weather to agriculture.
3. Identify some hazards associated with bad weather.
4. Describe some ways in which the weather affects human activity.
5. Describe some ways in which the weather affects other living things.

BEAUFORT WIND SCALE

Description	Observation
calm	smoke rises vertically
light air movement	smoke drifts slowly
slight breeze	leaves rustle
gentle breeze	leaves and twigs move
moderate breeze	small branches move
fresh breeze	small trees sway
strong breeze	large branches sway
moderate gale	whole trees move
fresh gale	twigs break off trees
strong gale	branches break
whole gale	trees are blown down, life threatening
storm	widespread damage, life threatening
hurricane	extreme damage, life threatening

Other devices which will work well are pinwheels, and garden propellers which are used to scare away birds from gardens.
Inflate a balloon, tie a string to it, and attach the string to the end of a stick. Tape a 30 cm x 30 cm piece of cardboard to the stick. Hold the stick vertically and allow the balloon to hang along the edge of the cardboard. As the wind blows, the balloon will move. Depending on the strength of the wind, the angle between the string and the stick will change. Put a mark on the cardboard to indicate the angle the string makes.
Or, for variety, divide the class into groups, assign the use of various devices to different groups, and compare the results.

Place the weather vane outside. It will align itself so that the end of the straw with the lump of modelling clay on it will point into the wind. Use a compass to determine the direction from which the wind is blowing.

A similarly designed weather vane, made of more durable materials such as wood or metal, can be constructed and installed on the roof of the school. Regular observations can be made. For permanent installation, a reference cross with the four cardinal points on a compass can be mounted under the weather vane. This project offers the potential of involving students from higher grades in the construction of the weather vane.

Place the barometer close to a wall. Tape a sheet of paper on the wall, making a reference mark on the paper to show where the tip of the straw is pointing. Observe the end of the straw every day for a few days. Give both girls and boys opportunities to take the readings. The device will show that a change is taking place. Students should be able to infer what is happening to the air pressure depending on the direction that the straw moves. (If the pointer end of the straw moves up, atmospheric pressure is increasing.)

Once a reading is taken, the gauge is emptied and supported vertically to allow water to enter it the next time it rains.

A ruler can act as a snow gauge. The ruler is pushed into the snow to determine the depth of the snow. Once a measurement has been taken, the fresh snow can be removed, so that the next time it snows only new snow will be recorded. The measurements should be taken in some sheltered location, where drifting will not cause inaccurate readings. A rain gauge can also be used to measure the amount of snowfall. It is less convenient because it has to be cleaned out after use, and it tends to get iced up.

Another aspect of this activity is to place a measured amount of snow in a transparent cylinder and allow it to melt. Measure the height of water left in the container. Develop a relationship between the depth of snow and the equivalent amount of water that is produced. Extend this idea to explain why farmers rely on a heavy winter snowfall to provide moisture for the soil.

The temperature readings on the two thermometers will differ. The difference in the two readings depends on the relative humidity. Tables can be obtained to determine the relative humidity based on the temperature readings from the wet and dry bulbs.

Take readings with the hygrometer in different places: inside the school; outdoors, in a sunny place, in the shade, in an open field, in a forest. This will develop the idea that variation in measurement will occur, depending on where those measurements are taken. Students need to know the importance of taking consistent measurements, consistent in method and location, if accurate weather forecasts are to be made.

• If there is fog during the winter, it will rain 100 days later.
• Dark clouds in the west -- stay home and rest.
• If a Ground Hog sees its shadow on Ground Hog's Day (Feb. 2) there will be 40 more days of winter.
• According to the Farmers' Almanac, the width of the stripes on a particular type of caterpillar can be used to tell if winter is going to be good or bad. Fat stripes mean there will be a cold, rugged winter. The thinner the stripes the better the weather will be.
• If March comes in like a lion it will go out like a lamb, but if it comes in like a lamb it will go out like a lion.
• When bees stay close to the hive, rain is close by.
• When teeth and bones and bunions ache, expect the clouds to fill the lake.
• Trappers say that the thickness of fur pelts is a good indication if the weather is going to be cold.
• If deer stay in the swamp then rainy weather can be anticipated.
• If animals are constantly on the move or eating frequently, it could mean rain or cold weather is on the way.
• Animals and people have quick tempers when a low pressure area is moving in.
• The tilt of the crescent of the new moon will determine the amount of rainfall over the next month. If the crescent is more vertical in appearance it will be a rainy month, but if the crescent appears to be lying more horizontally it will be a dry month.
• If it is cloudy in the daytime but does not rain, it will get colder in four or five days.
• The higher the clouds the better the weather.
• Rainbow in the morning, shepherd take warning; Rainbow toward night, shepherd's delight.
• If birds begin to migrate earlier or if rabbits turn white sooner in the fall, it means that winter will come early.
• Some elderly people complain that their arthritis is more severe immediately before a major storm.

Have students ask parents and other people in the community if they know of any other such sayings about the weather. Invite an elder to explain how weather predictors are used. There are many popular weather sayings like these. They form an interesting aspect of local culture and folklore. Many of them may have originated as a result of long-term weather forecasting and prediction.

Farmers and ranchers could be interviewed on the effect weather has on various agricultural operations. The class could establish an interview guide before proceeding. Questions could focus on how the weather affects health, crop yield and quality, or food and water supplies for animals. Other farmers or ranchers could be interviewed for an historical perspective of weather and the impact it had on early settlers.

Elders could be invited to come to school to discuss the signs used by Indians to predict weather. Popular folklore dealing with weather may vary from one culture to another. It might be interesting to compare the weather lore from several different cultures.

Have students undertake long-term weather studies in order to be able to test the validity of these or other weather sayings. They can keep a weather journal to record long-term results.

This activity could involve some interesting long-term studies. It challenges students to search for patterns and trends in recorded data. It also challenges them to explore a question scientifically, with an open mind. Some of this weather lore may have some truth to it. After all, the Farmer's Almanac claims it is even more accurate in its long-term weather forecasts than Environment Canada!

Have fun with an activity such as this. The students may come up with interesting observations which might tend either to support or reject some of these popular sayings. Perhaps some of their observations may even be inconclusive. Whatever the case may be, they will certainly get the impression that science is fun and does not always have to be done so seriously.

When you see a cloud coming up in the west, at once you say that it is going to rain -- and it does. (Luke 12:54)

Students should be able to scrutinize information carefully for its validity. Using a scientific approach, they have a means at their disposal of testing various claims about weather or other things.

The weather will remain fair if:

• blows gently from the west or northwest.
• the barometer rises or remains steady.
• cumulus clouds are in the sky.
• clouds stay high in the sky and flow with the prevailing winds.
• smoke rises and disappears.

A storm may come when:

• the barometer begins dropping rapidly.
• cumulus clouds begin to develop vertically.
• clouds are dark and threatening.
• birds are not as active as usual.
• the wind shifts in direction.

After collecting weather data for a period of time, have the students examine the data to see if such generalizations are valid. Once they have made the generalizations, have them continue taking weather measurements, and using the generalizations to make weather predictions. If the predictions are not accurate, have them scrutinize the generalizations to see if improvements can be made. Ask students to suggest how such generalizations might be helpful to people.

Make weather observations at the same time each day, and to continue the activity through a significant portion of the school year. Teachers who are camera enthusiasts may want to take a weekly picture of the same scene to make a photo montage record of the changes observed. Students could also get involved in using photography as a means of data collection. Date the pictures and keep them over the years to make long-term comparisons. Involve older students or a local photography club in this project.

Look for examples of poems and stories in which feelings and emotion are evoked by making reference to the weather. Biblical passages, such as those dealing with The Flood or Old Testament accounts of drought can be related to science by explaining how important weather was to people and to the events that took place. Use these works to enhance what students have learned in science.

Below are some poems which deal with the weather. Integrate them with other Science and English Language Arts activities.

Discuss why dew forms on some surfaces but not on others. What characteristic must a surface have to permit dew to form on it? Try the activity using a variety of different types of containers made of different materials such as glass, plastic, paper, ceramics, and so on.

Extend the idea to show how frost forms by adding several tablespoons of 48-0-0 fertilizer to a glass of a water-ice mixture that is at 0 °C. Stir the mixture to help the fertilizer dissolve.

During a winter cold snap, ask students to observe what surfaces have frost on them in the morning. List those surfaces that have frost on them and other surfaces which did not have frost on them. See if the types of surfaces in each list have some things in common which might enable or prevent frost formation.

The activity might raise more questions than it answers. For example, why does frost usually form on the outside of a car windshield and the inside of a house window? Why does condensation form on the outside of a glass filled with ice water if it is colder than the surroundings, but on the inside of windows in houses which are warmer than the surroundings? Frost will form on the outside of a glass containing a salt and chipped ice mixture. How is frost related to dew?

Of all of the many troubles that weather imposes on humans, drought has probably had the greatest overall impact.
- Encyclopedia Britannica, Science and the Future: 1984.

A panel of "experts" could be brought in to debate this idea, or local community members could take opposing positions and debate. This would enable students to gain some experience with how a debate is conducted. They could even judge the debate to determine which of the opposing viewpoints has been presented most convincingly.

Students should reflect upon the impact that drought has had on their lives. Urban students could identify with water rationing and dust storms. Rural students would be able to identify with many impacts on their lives.

Role playing could be used to evaluate the statement. Students could take different roles and discuss the significance of the statement from the point of view of people having different interests to protect.

Invert the bottles. Observe the way in which the water flows. Measure the amount of time it takes for the water to be transferred from the upper bottle to the lower one.

As the bottles are inverted, try to swing them in a circle, so the liquid inside begins to rotate as it empties. This might take some practice. As soon as the bottles are inverted, swirl them quickly so that the top bottle rotates more than the bottom one, inscribing a conical pattern. Observe the whirlpool that forms. Measure the time required for the liquid to pour into the bottom container if a whirlpool is present. Have students explain why the liquid is transferred more rapidly if a whirlpool exists.

Ask students to evaluate the subjective decisions that go into developing something like a Climate Severity Index. See if students can come up with their own criteria for developing a Climate Severity Index. Obtain weather statistics from different parts of Canada, or from elsewhere in the world, and see how different locations measure up on that index.

Below is an example of some of the listings in Environment Canada's Climate Severity Index (CSI):

Location	CSI
Victoria	13
Vancouver	18
Calgary	34
Toronto	35
Edmonton	37
Saskatoon	42
Montreal	44
Regina	47
Winnipeg	51