Monitoring the Atmosphere
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Transparencies |
Assessment Rubric Curriculum Expectations Webliography |
Canadian Weather
Canadians have perhaps the most diverse weather conditions of any country on Earth. Our weather ranges from sweltering tropical days in the Summer to perishingly cold nights in the Winter. Like people every where, Canadians love to talk about the weather, but few understand what causes the weather that we experience.
Unlike seasonal trends, such as June will be warmer than March, detailed daily weather is difficult to accurately predict for more than a few days in advance. The truth is that forecasts for 6 to 12 hours in advance have improved only slightly during the past 200 years. The greatest advances have been made in long term forecasting, largely due to satellite imagery and electronic data collection. Powerful computer programs compile and analyze the huge amounts of weather data that is collected from around the world to make long term forecasts that are constantly improving.
Weather Instruments
The principle instruments that are used to forecast the weather are the thermometer, the barometer and the wind-vane. With these three simple instruments it is possible to make quite accurate weather predictions for the approximately 12 to 24 hours into the future.
In fact these instruments were well understood and utilized extensively by navigators plying the high seas from the eighteenth until late in the twentieth century when modern satellite technology revolutionized meteorology. Weather maps still display the essential elements required to make weather predictions, that is, barometric pressure (in kilopascals), temperature (in Celsius degrees), wind direction (angular degrees) and speed (in kilometres per hour).
The Importance of Weather
It seems obvious to state the fact that weather, and the ability to predict weather, is extremely important in the regulation of human activities. The success of such activities as planting and harvesting, recreation and sports, weddings and invasions, are all dependant to some extent on the weather.
The D-Day invasion of Normandy was almost foiled by the vagaries of the English Channel weather, the Challenger space shuttle disaster was a consequence of the pre-launch weather, the wide spread destruction of cites along the Gulf coast is due to hurricanes spawned by the weather conditions off the coast of Africa ... the list is almost unlimited.
Teacher's Notes
Things to emphasize
- All weather events, on all scales, are driven by energy from the Sun.
- All agriculture (and hence human survival) is dependant upon the weather.
- Seasons cannot be accurately predicted from the weather, therefore seasons are calendar events created by astronomers.
- Climate is the "average" weather of a location, averaged over twenty five years or more.
- Extremely general weather predictions based on seasons, can be predicted with 100% accuracy. ( e.g. The first day of summer begins at 4:32am EDT Tuesday June 21st, and it will be warmer than winter)
- Generalized weather predictions based on climate, can be predicted with 90-99% accuracy( e.g. In July, Arizona will be hot and dry)
- Detailed daily weather predictions based on daily observations of barometric pressure and wind conditions, can be predicted with varying (depending upon whom you ask!) accuracy.
Build Some Instruments
Build A Hygrometer
Use a pin or a tack to fasten a humidity pointer onto a piece of cardboard, labeled as indicated in the figure shown below. Tie one end of a strong human hair to the humidity pointer, and the other end of the hair to the top of the cardboard. Treat the pointer as a third class lever. The closer the hair is tied to the fulcrum, the more movement you will observe in the pointer as the humidity changes. Although the dimensions of the hygrometer are not critical, the longer the hair, the better.
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A classroom hygrometer
A human hair is sensitive to the amount of water vapour in the air. As the air becomes more humid, the natural elasticity in the hair "relaxes" and the hair gets longer.
Conversely, a dry hair contracts and becomes shorter.
It is this property of hair that is used to build the classroom hygrometer shown in the figure to the left.
This device is for indoor use only.
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Build A Barometer
A classroom barometer
A two litre juice can with the lid cut off makes a good barometer. A cut latex balloon, held in place with an elastic band, is used to seal the air in the container.
The "pointer" is made of two drinking straws taped to the centre of the balloon, and resting on the lip of the juice can as shown. Slit one end about 1-2cm and insert the end of one straw inside the other before taping them together. Fold a piece of sturdy paper in half and mark it in easily readable increments. Place the paper beside the barometer so that the pointer extends over to the paper, but does not touch it.
NOTE: This device is also sensitive to changes in temperature as well as pressure, therefore it is recommenced that one place the barometer in a location where there temperature is likely to remain fairly constant.
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Activities
- Plot a daily record of the barometric pressure taking observations twice a day for at least one month. Record with each reading the current weather conditions.
- Calibrate the classroom barometer in kilopascals using the barometric pressure from local radio or TV weathercasts.
- Investigate how "air masses" are related to high and low pressure cells.
- Monitor the humidity in your classroom. Is there any relationship between the daily weather, the seasonal weather and the humidity of the air in the classroom? Can you explain any patterns you find?
On the surface of the Earth we live at the bottom of an ocean of air. And just like any ocean, the ocean of air has waves rolling along the top. Of course, unlike the surface of the ocean, the atmosphere has no "top"", but it still has waves on it nonetheless.
As the waves pass overhead we can observe their passage as changes in barometric pressure on the Earth's surface.
It is the passage of these waves that is responsible for the changes in weather that we experience each day.
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Under a low pressure the weather is stormy (Winnipeg), under a high pressure the weather is fair (Calgary). When the barometer is "falling", (changing), and pressure is becoming lower (ThunderBay) the weather will get worse within the next 12 hours. When the barometer is "rising ", that is changing and pressure is becoming higher (Regina) the weather will get much better within the next 12 hours. |
By carefully monitoring changes in a barometer one can make 12h weather forecasts which are about 90% accurate in terms of general weather conditions.
It has been stated that "without astronomy there can be no civilization."
The reasoning behind this statement is this:
- The first step beyond the nomadic, hunter-gatherer society, requires organized agriculture.
- Organized agriculture requires a knowledge of when to plough fields and sow crop seeds.
- Weather is far too variable to predict accurately the true beginning of Spring (or related events such as the flooding of the Nile in ancient Egypt) For example, if one were to plant a crop too early it may be killed by frost or washed away by floods. Planting a crop too late in the year may not allow it to mature or ripen.
- Astronomical events are required to know exactly when the seasons are changing and therefore when to plant crops.
Discuss the variability of the weather with respect to the seasons with your students.
Assessment Rubric
R | Level 1 | Level 2 | Level 3 | Level 4 |
| significantly below the standard | approaches the standard | the standard | exceeds the standard | |
(below 50%) | (50-59%) | (60-69%) | (70-79%) | (80-100%) |
Understanding of Basic Concepts | ||||
produces insufficient evidence to demonstrate learning demonstrates significant misconceptions requires additional learning activities and remediation | demonstrates limited understanding of weather dynamics | demonstrates some understanding of weather dynamics | demonstrates general understanding of weather dynamics | demonstrates thorough understanding of weather dynamics |
| by providing partial explanations of heat transfer in the hydrosphere and atmosphere and its effects on air currents, changes in barometric pressure on the Earth's surface, and changes in daily weather | by providing partial explanations of heat transfer in the hydrosphere and atmosphere and its effects on air currents, changes in barometric pressure on the Earth's surface, and changes in daily weather | by providing complete explanations of heat transfer in the hydrosphere and atmosphere and its effects on air currents, changes in barometric pressure on the Earth's surface, and changes in daily weather | by providing complete explanations of heat transfer in the hydrosphere and atmosphere and its effects on air currents, changes in barometric pressure on the Earth's surface, and changes in daily weather | |
| with significant misconceptions / inaccuracies | with minor misconceptions / inaccuracies | with no significant misconceptions / inaccuracies | with no misconceptions / inaccuracies | |
Application of Critical and Creative Thinking Skills and/or Processes | ||||
produces insufficient evidence to demonstrate learning requires additional learning activities and remediation | applies appropriate skills/strategies to construct classroom weather instruments, take observations and analyse data with limited effectiveness | applies appropriate skills/strategies to construct classroom weather instruments, take observations and analyse data with some effectiveness | applies appropriate skills/strategies to construct classroom weather instruments, take observations and analyse data with considerable effectiveness | applies appropriate skills/strategies to construct classroom weather instruments, take observations and analyse data with a high degree of effectiveness |
Communication of Required Knowledge | ||||
produces insufficient evidence to demonstrate learning requires additional learning activities and remediation | communicates unclearly or imprecisely | communicates with some clarity and precision | communicates with general clarity and precision | communicates clearly and precisely |
| rarely using appropriate scientific conventions, vocabulary, and terminology | sometimes using appropriate scientific conventions, vocabulary, and terminology | usually using appropriate scientific conventions, vocabulary, and terminology | always using appropriate scientific conventions, vocabulary, and terminology | |
Application of Required Knowledge | ||||
produces insufficient evidence to demonstrate learning demonstrates significant misconceptions requires additional learning activities and remediation | makes very simple connections between scientific concepts related to weather dynamics and our ability to predict weather | makes simple connections between scientific concepts related to weather dynamics and our ability to predict weather | makes connections of some complexity between scientific concepts related to weather dynamics and our ability to predict weather | makes complex connections between scientific concepts related to weather dynamics and our ability to predict weather |
Curriculum Expectations
Quebec Curriculum Expectations:
The Physical Science (Physical Environment) course is designed to help the students :
- gain knowledge of certain physical phenomena in the environment, and consequently, learn about the properties of matter;
- develop certain skills necessary for scientific experiments;
- develop certain attitudes regarding the scientific method, such as a critical sense and a taste for research. This will help the students increase their awareness of the impact of modern technology on the physical environment.
Pan-Canadian Curriculum Expectations:
Grade 10
Curriculum Strand - Weather Dynamics
Knowledge Expectations
- describe and explain heat transfer within the water cycle.
- describe and explain heat transfer in the hydrosphere and atmosphere and its effects on air and water currents.
- describe how the hydrosphere and atmosphere act as heat sinks within the water cycle.
- describe and explain the effects of heat transfer within the hydrosphere and atmosphere on the development, severity, and movement of weather systems.
- analyse meteorological data for a given time span and predict future weather conditions, using appropriate methodologies and technologies.
Skills Expectations
- compile and display evidence and information, by hand or computer, in a variety of formats, including diagrams, flow charts, tables, graphs, and scatter plots.
- identify and explain sources of error and uncertainty in measurement and express results in a form that acknowledges the degree of uncertainty.
- provide a statement that addresses the problem or answers the question investigated in light of the link between data and the conclusion.
- identify new questions or problems that arise from what was learned.
- identify questions to investigate that arise from practical problems and issues.
- use library and electronic research tools to collect information on a given topic.
- select and integrate information from various print and electronic sources or from several parts of the same source.
- develop, present, and defend a position or course of action, based on findings.
Science, Technology, Society and the Environment Expectations
- identify examples where scientific understanding was enhanced or revised as a result of the invention of a technology.
- analyse why scientific and technological activities take place in a variety of individual and group settings.
- describe examples of Canadian contributions to science and technology.
- relate personal activities and various scientific and technological endeavours to specific science disciplines and interdisciplinary studies.
- illustrate how science attempts to explain natural phenomena.
- explain how scientific knowledge evolves as new evidence comes to light.
Webliography
Canadian Weather
Canadian Weather Forecasts
Five day weather forecasts from coast to coast to coast.
Environment Canada
Weather Instruments
Canada Centre for Remote Sensing
Access information from the program responsible for receiving, processing and archiving Earth observation data. Find information on topics including climate change, northern development and natural hazards.
Natural Resources Canada
The Importance of Weather
Climate Change - Government of Canada
Find out about climate change issues, their impacts and what Canada is doing about it.
Government of Canada
Understanding Stratospheric Ozone
Learn about the stratospheric ozone layer, ozone depletion, and UV radiation. Find out about scientific research in the polar regions.
Environment Canada
Prepared by the YES I Can! Science team
www.yesican-science.ca
