Movin' Around Students do not have to start a new page of notes but they can if they want.

Why is the equator warmer than the poles? The rays of the sun strike the Earth directly at the equator. At the poles the curvature of the Earth spreads the rays out.

The solar radiation heats the surface of the earth. Ask students how the ground transfers heat to the air before clicking the animation. Click to make the “molecules” appear. Ask students what happens when the molecules touch the ground. (heat is transferred, molecules gain energy, molecule move faster) Ask students what happens when the molecules become heated. (the rise) What type of energy does this show? (convection) (Teacher Notes – the vocabulary is a review from previous years but you may need to go over it multiple times if they don’t seem to remember.) Heat is transferred to air molecules that come in contact with the ground.

If all the air is rising, Why doesn’t this person suffocate? The solar radiation heats the surface of the earth. Reinforce the methods of heat transfer as they appear. Have several students answer the question that appears. The immediate response is “as the air cools it sinks”, you will need to point out that it can not sink in the same location it is rising in because the rising air would push it back up. Try to get students to realize the air must come from the sides. Use the analogy of a vacuum cleaner sucking things up. Heat is transferred to air molecules that come in contact with the ground.

Cooler air is pulled in from other places What is this called? As the Warmer Air Rises… Cooler air is pulled in from other places Read through parts of the slide as they appear. Allow time for students to answer the question. What is this called?

WIND Answers the question from the previous slide.

Low Pressure WIND High Pressure Convection current – the transfer of heat through movement in the atmosphere. Low Pressure WIND Why does the warm air rise? – it is less dense (kids should remember this from the convection in the mantle) The rising air leaves room for air to move in from other locations (click) We call this wind (click) As the air rises it cools and spreads out along the top of the troposphere (click) When air reaches a cooler location it sinks (click) This cycle of air is called a convection current (click) Allow students time to write the definition, the next click will make it disappear. (click) The part of a convection current that moves across the surface of the earth is called (click) wind. The rising air creates an area of low pressure (click) Low pressure means the air is not putting much pressure on the Earth’s surface. The more dense sinking air creates an area of high pressure (click). High pressure means the air is putting pressure on the Earth’s surface. High Pressure

The Wind Winds are the result of uneven heating of the Earth’s surface This uneven heating causes differences in air pressure to develop Molecules always move from areas of high pressure to areas of low pressure Student notes Ask students if they like being under a lot of pressure/stress. Explain that the air doesn’t like high pressure because it doesn’t like being pushed down into the ground.

GLOBAL PRESSURE & WIND Antarctic circle 66.5°S Arctic circle 66.5°N North Pole 90°N South Pole 90°S Equator 0° Tropic of Cancer 23.5°N Tropic of Capricorn 23.5°S ZONE of least heating produces HIGH PRESSURE HIGH ZONE of greatest heating produces LOW PRESSURE LOW Click to bring in a model of the Earth and labels. Ask students to explain the temperature patterns you would expect. Ask students where the warmest part of the earth is? – Equator How would you expect the air at the equator to move? – rise because it is warm CLICK and review that rising air creates Low Pressure Ask students where the coldest part of the earth is? – poles How would you expect the air at the poles to move? – sink because it is cold CLICK and review that sinking air creates High Pressure How would you expect air to move across the planet? – From the poles to the equator (high to low) HIGH ZONE of least heating produces HIGH PRESSURE How would you expect air to move across the planet?

GLOBAL PRESSURE & WIND Global circulation depends on differential heating over the globe. The system is driven by strong equatorial heating, causing LOW PRESSURE. POLAR HIGH EQUATORIAL LOW

GLOBAL PRESSURE & WIND Equatorial air descends over the tropics, where HIGH PRESSURE dominates; where it diverges at ground level. This tropical air blows towards the equator, completing the equatorial cell. POLAR HIGH TROPICAL HIGH EQUATORIAL LOW

GLOBAL PRESSURE & WIND Some of the sinking air at the Tropical High moves towards the mid-latitides where it meets cold, dense polar air blown out from the polar HIGH PRESSURE. POLAR HIGH TROPICAL HIGH EQUATORIAL LOW

GLOBAL PRESSURE & WIND These contrasting tropical and polar air masses meet at the POLAR FRONT LOW PRESSURE BELT, where the warmer air is forced upwards by the polar air. POLAR HIGH POLAR FRONT (LOW PRESSURE) TROPICAL HIGH EQUATORIAL LOW

And Then the World Turns

Theoretical wind which would result solely from pressure gradient CORIOLIS FORCE High Pressure gradient wind blows from high pressure towards low pressure. The earth’s rotation diverts this wind direction sideways. This force is called the CORIOLIS FORCE. The Coriolis force diverts wind to the right in the northern hemisphere; to the left in the south. Theoretical wind which would result solely from pressure gradient Actual wind which blows, as diverted by Coriolis Force Low Merry Go Round Demonstration Coriolis Explained

Goes to the mid-latitudes Trade Winds – pattern of air movement in the tropics Goes to the equator Easterlies – pattern of air movement at the poles Goes to the mid-latitudes Westerlies – pattern of air movement in the mid-latitudes Goes to the poles Use this graphic to lead students in a discussion of global wind patterns. Have students use the information from the previous slides to explain the locations and directions of the arrows. Why don’t any of the arrows go away from the equator? – air always moves toward low pressure and the equator is always low Why don’t any of the arrows go in straight line? – Coriolis

Why do the gas giants appear to have a striped surface? They have the same global wind patterns as earth.

Jet Stream – is a band of fast moving air in the stratosphere. Formed where Westerly winds meet the Easterly winds The weather map should be familiar to students. Ask them what the “H” and “L” mean. What can they tell you about the air in the specific locations. Explain that in the Northern Hemisphere wind moves around a low pressure counter clock-wise and goes clock-wise around high pressure. Point to an area on the map (not an H or L) and ask students to predict the wind direction for that spot. (wind will blow towards the closest “L”) Ask students if the H and L are always in the same location (no). How do meteorologist predict where they will go? Click / Click – give students a chance to write the notes. Explain that the exact latitude of the jet stream can change but for most of the year it is directly over the United states. Our pressure systems always move from west to east. Click TEACHER NOTE: Stratosphere is the atmospheric layer just above the troposphere. Jet Stream Video

Summarizing Convection What is convection? Where does convection occur? In what states of matter does convection occur? What other liquid could convection occur in on Earth? These questions are designed to tie the information back into the previous unit and transition to ocean currents What is convection? –transfer of heat by movement Where does convection occur? – atmosphere & mantle In what states of matter does convection occur? – gas & liquid What other liquid could convection occur in on Earth? Ocean

Ocean Currents Atmospheric Currents Ocean Surface Currents Depend on temperature Ocean Surface Currents Depend on wind

Ocean Currents Picture 1 – shows global wind patterns Picture 2 – shows the ocean currents that result from the trade winds

Ocean Currents Picture 1 – shows the relationship between global wind patterns and the Northern Atlantic ocean As you click the arrows illustrating the ocean current will appear. As they appear discuss the relationship between them and the winds.

Ocean Currents Picture 1 – shows Atlantic Ocean currents

Wind-drive ocean surface currents Wind driven surface currents Wind-drive ocean surface currents How fast? A few miles/hr (Gulf Stream off of Miami = 4.5 mph) How much? Total water in ocean surface circulation = about 100 Amazon Rivers (20 million m3/s).

Ocean Currents Illustrated The links on this slide show how the ocean currents have moved all the trash dumped in the ocean to one location creating a the largest garbage dump in the world. The second link also discusses the impact this has on marine life. Green Peace Today Show Investigates