Chapter 9 Lesson 5, "Wind Patterns"

Materials:

• Worksheet, "Wind Patterns, Terms Review"

Objective:

• Students will explain what causes air to move.
• Students will recognize how air moves in wind cells.
• Students will identify three wind belts.

Anticipatory Set:* Perform a demonstrations of how warm air rises and cool air sinks. An easy demo is to use a meter stick as a teater-totter. Attach two identical objects that can be acted on by wind currents on the ends. Place a candle on one end and the meter stick raise heat up on the heated end and sink on the cool end. This demstrateds that heated air rises and cool air sinks. Why does this happen? Show the students a column of hot air molecules spaced widely apart and a column of cold air particles spaced close together. What would happen to the molecules of the cool air if it were heated by the sun. If cool air were next to the warm air what would it do? (move under it and then heat up) What is the term for this rising warm air, replacement by cool air, and then heating and rising again in a cycle? (wind cell wind cell 2, Wind Cell 3) Next pull out a globe and ask the students if the sun heats the Earth evenly. What part of the Earth gets the most heat? Which gets the least? Is there anything else that can affect how the earth is heated? (clouds 1, Clouds2, type of habitat rainforest, ocean, desert, etc.) Show a picture of a desert and rainforest. Which will heat faster? Which will cool faster? Show a picture of a cloudy area, sunny area. If they are both at the same latitude which will heat faster? Which will cool faster?

Teacher Input:* Remind students of air heating at the equator and cooling at the poles. Do winds travel directly south from the poles and do they rise and travel north from the equator? (winds from poles to equator) What could affect the wind movement? Show a spinning earth. The winds slowly turn to the right in the northern hemisphere and left in the southern hemisphere. This is from the spinning of the globe known as the Coriolois effect. What type of wind currents would this create on the surface of the earth? (Wind Belt and Trade winds) How was this used 200 years ago and still today? Would a ship be able to depend on winds near the equator? This area is refereed to as the doldrums and ships could get caught in this area of high heat and no winds for weeks. There are then several areas across the surface of the earth where the wind generally moves in one direction. Prevailing westerly's, Polar easterlies, Jet Stream.

Are wind currents still depended on today? Who uses wind currents? (jet stream, "pilots", wind generators "150 million kilowatt less than 1% of the US's electrical production", windmill water pump, windmill grinding stone, )

Guided Practice:* Students will answer the questions on Page 224 in class.

Independent Practice:* Students will complete the worksheet, 'Wind Patterns: Terms Review"

Check for Understanding:* Students will take the quiz on Lesson 5, Wind Patterns.

Duration:

30 minutes + 10-15 for Independent Practice (Could be longer if taken for homework).

Alaska Content Standards Addressed in this lesson:

• SCI A-1 Students will understand models describing the nature of molecules, atoms, and sub-atomic particles and the relation of the models to the structure and behavior of matter (Structure of Matter);
• SCI A-4 Students will understand observable natural events such as tides, weather, seasons, and moon phases in terms of the structure and motion of the earth (Earth);
• SCI A-6 Students will understand that forces of nature cause different types of motion and describe the relationship between these forces and motion (Motion);

• SCI A-15 Students will use science to understand and describe the local environment (Local Knowledge); and: