This unit is intended for middle school students between grades 6 and 8. The use of an easily observed and measured discipline such as meteorology encourages experimental design, direct observation and subsequent reinforcement of science content.
The unit has the objectives of demonstrating to students that:
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- Solar radiation is not equally distributed on the surface of the Earth
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- Energy can be described and measured in terms of molecular motion
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- Temperature is the way we measure average molecular motion
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- Pressure is the amount of force per unit area
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- Air contains various amounts of water vapor
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- Weather is strongly affected by the location of a place relative to large body of water
When working with middle school students, it is essential to keep their unique learning styles in mind. Lecture is generally ineffective. Brief introduction followed by minds- and hands-on activity, with science log book entries results in deeper learning. Student groups should follow up classroom activities with discussion and presentation of results.
This unit is broken down into six main topics, to be completed in approximately six class sessions of 45 minutes each. Each lesson is broken down into introduction, objective, materials, activity procedure, and wrap up with discussion.
Students benefit from concrete examples of scientific processes. For this reason, this unit includes numerous activities.
1. Radiational energy will be explored with an activity which relies on the temperature differences observed when objects are exposed to visible light and when they shaded. Extensions of this activity are to make use of photovoltaic solar cells for quantitative value collection, and changing the angle of the visible light source.
2. Temperature of gases will be changed and resulting volumes measured. Additionally Celsius temperature readings will be converted to Kelvin and Fahrenheit.
3. The uneven heating of the Earth will be investigated by placing thermometers in identical environments, but different materials (such as sand or soil and water). A heat source will be introduced (such as a classroom radiator or 100 watt incandescent light) and the change in temperature will be monitored over a classroom period and throughout the school day. Data will be collected and graphed. An extension is to evaluate uneven heating based on object color.
4. Pressure will be evaluated by using an anemometer (a wind gauge) and a current forecast, which shows low, and high pressure systems. Extensions include heating air in an Erlenmeyer flask with a balloon over the opening, massing a balloon before and after filling with air (or putting two balloons on the ends of a lever, such as a broom handle or meter stick with pivot point in the middle, and then filling one with air), making barometers with soda bottles, and when outdoors simply dropping light objects (such as leaves) to observe and make a rudimentary measurement of wind speed and direction.
5. In order to observe atmospheric water vapor, we will create a weather system in a clear plastic box with a reservoir in the top for ice and a place inside for a warm mass. Water vapor will condense as liquid on the underside of the ice, simulating the hydrologic cycle.
6. The impact of geographic location (and heat capacity of water) will be explored by consultation with online weather maps to make real-time predictions and comparisons of temperatures at various coastal regions (Pacific, Great Lakes, and Atlantic). With deeper understanding of how weather works, students may now make predictions for weather in regions around the country and world.
Students learn best by doing background reading and having access to high quality visuals (such as the WWW, posters, and videos). Discussion with peers is powerful as in this age group interpersonal communication is a startling effective way to have students learn new ideas.
In science courses we want to give students as many experiences with materials as possible. Hands-on activities without background information are usually not very effective at getting important concepts across. The activities used in this unit support the concepts being addressed.
The International System of Units (SI) is the preferred measurement to use in science. In this system, we measure:
Volume in liters,
Mass in grams (weight is technically mass x gravity, on Earth mass is synonymous with weight)
Length in meters, and
Temperature in Celsius, (with 0 C the temperature at which pure water freezes and 100 C the temperature at which the molecules have enough energy to begin to change state and go from liquid to gas. This is also called the boiling point).
