Catalyst: 1. During the day, which one heats up faster, land or water? WHY?? 2. During the night which one cools down slower? 3. How does heat move? (hint: from what to what?) 4. What are the differences between a cold and a warm front? 5. Read the Winds Article on your desk and answer the questions. Write on your own paper.
Local Winds vs. Global Winds There are two types of winds. Global winds are the types of wind that appear all over the world because of the following reasons: Pressure differences Coriolis Effect Local winds depend on the local landforms if there is a body of water near, or if you are next to a mountain
Local Winds Generally move short distances and can blow in any direction Caused by geographic features that produce temperature differences
Brain Pop: WindFrom beginning to 1:00 then start from 1:57 http://www.brainpop.com/science/weather/wind Answer the following questions during the Brain Pop Video 1. What causes wind? 2. In which direction does the air move when it is heated? 3. In which direction does the air move when it is cooling off? 4. What are some things that cause local winds?
Sea Breezes Happen during the day During the day: High pressure (more dense) air is created over the ocean and low pressure (less dense) air over land due to uneven heating What is heating the earth unevenly? During the daytime, air moves from the ocean to the land creating a sea breeze Ocean à land = sea breeze
THINK!!! What creates these pressure differences?? Remember: air pressure and density are related! What can make something more dense (more pressure) or less dense (less pressure)? Temperature! cold=high pressure warm=less pressure So during the day is water hotter or colder than land? Colder so it is more dense/higher pressure Dense cold air over oceans pushes to warm area over land as WIND! Wind moves: ocean à water = sea breeze!
Draw out a Sea Breeze with me! Draw this on your sheet
Catalyst 1. What is the relationship between density and pressure? 2. Where does the wind that we feel in a sea breeze start from, the sea or the land? 3. What time of day does a sea breeze happen? 4. Draw out a sea breeze from yesterday: include pressure, density, temperature and the direction of the wind with the arrows
Land Breezes Happen at night At night: Low pressure (less dense) air occurs over the ocean during the night and high pressure (more dense) air over land due to the uneven heating of earth At night, wind moves from the land to the ocean creating a land breeze Land à ocean = land breeze
What causes these pressure differences? At night is land hotter or colder than water? If land is (hotter, colder) at night that means the air over it is (more, less) dense More dense (more pressure) cold land air wants to take the place of the warm ocean air that is rising! Wind moves land à water = land breeze!
Draw out a Land Breeze with me! Draw this on your sheet
Check for Understanding: What direction to sea breezes flow from and to? What causes these local wind movements? What time of day do land breezes occur during?
1. What directions do sea breezes move from and to? 2. What direction do land breezes move from and to? 3. What causes the air to move (explain the idea of density/pressure and temperature!)? 4. Winds Reading DO NOT WRITE ON!
Global Winds The combination of pressure belts and the Coriolis Effect cause global winds There are three types! polar easterlies, westerlies, trade winds Brainpop! 1:14 2:26 http://www.brainpop.com /science/weather/wind/
Global Winds 1 = tradewinds 2 = westerlies 3 = polar easterlies 3 3 2 1 1 2 Global winds divide the Northern Hemisphere into 3 slices and the Southern Hemisphere into 3 slices. The slices are mirror images of each other (just like lines of latitude!)
Trade Winds
Trade Winds Winds that blow from 30 almost to the equator They blow from the north east to the south west. Called the trade winds because of their use by early sailors Push tropical cyclones (hurricanes) across the oceans!
Westerlies
Westerlies Wind belts found between 30 and 60 latitude Blows from southwest to northeast Carry warm moist air from tropics over the continents
Polar Easterlies
Polar Easterlies Wind belts that extend from the poles to 60 latitude Blow from east to west Formed from cold sinking air moving from the poles creating cold temperatures Weaker winds
Check for Understanding: Question 1 What causes winds?
Answer Winds are caused by the uneven heating of Earth s surface, which causes pressure differences
Check for Understanding: Question 2 What are the three types of global winds?
Answer Polar Easterlies Westerlies Trade Winds
Question 3 What is the difference between a land breeze and a sea breeze?
Answer Sea breezes occur during the day when the land is warmer than water and a land breeze occurs at night when the water is warmer than land
Wind Guided Practice & Velcro Boards!
Exit Ticket!