Hook ‘em! I recommend starting the unit or perhaps each day in the unit with a relevant, exciting video clip. Here are some examples: Train vs. Tornado (have students describe the sky, clouds, trees, wind as the train crosses a weather front and is lifted off the tracks by a tornado!!! Relate to inertia when the cars at the back stay in motion and crash into the front!) http://www.youtube.com/watch?v=azV5bC2br-Q Destructive Hail Storm in Arizona - http://www.youtube.com/watch?v=DuMX9AM9BrE Lighting in Slow Motion http://www.youtube.com/watch?v=7kI1d7DMbco Awesome Cold Front Time Lapse that ends in SNOW! http://www.youtube.com/watch?v=0NoPXm7d5Tc Shows how the cold air mass moves in, clouds form, snow, etc! Bill Nye – Storms video – BEST El Nino explanation (7 min in)

The TEKS Know that climatic interactions exist among Earth, ocean, and weather systems. 8.10 (A) recognize that the Sun provides the energy that drives convection within the atmosphere and oceans, producing winds and ocean currents;

The TEKS Know that climatic interactions exist among Earth, ocean, and weather systems. 8.10 (B) identify how global patterns of atmospheric movement influence local weather using weather maps that show high and low pressures and fronts;

The TEKS Know that climatic interactions exist among Earth, ocean, and weather systems. 8.10 (C) identify the role of the oceans in the formation of weather systems such as hurricanes.

Weather & Oceans Power point from Nadia Shanaa 8th Grade Science Burnet Middle School

What’s so interesting about weather? : Train vs. Tornado (While you watch the video clip describe the sky, clouds, trees, wind as the train crosses a weather front and is lifted off the tracks by a tornado!!! Relate to inertia when the cars at the back stay in motion and crash into the front!) https://www.youtube.com/watch?v=EWH6QYClQvQ Destructive Hail Storm in Arizona - http://www.youtube.com/watch?v=DuMX9AM9BrE Lighting in Slow Motion http://www.youtube.com/watch?v=7kI1d7DMbco Ground lightening Awesome Cold Front Time Lapse that ends in SNOW! http://www.youtube.com/watch?v=0NoPXm7d5Tc

Factors Affecting Our Weather 1. Uneven heating of Earth’s surface 2. Differences in air pressure 3. Moisture 4. Topography 5. Rotation of Earth

transfer of heat by the movement of warmed matter CONVECTION transfer of heat by the movement of warmed matter

Hot Air is Less Dense!

Force = Mass X Acceleration increase increase Gravity pulls with more force on heavier objects! The Bigger They Are, The Harder They Fall!

What is most dense SINKS! Atmospheric Density What is most dense SINKS! Therefore, hot (less dense) air rises and cool (more dense) air sinks.

CONVECTION

CONVECTION

CONVECTION Moves air in the atmosphere!

CONVECTION causes deep ocean currents!

CONVECTION Wind over the shore changes direction because of EARTH’S UNEVEN WARMING & COOLING!

CONVECTION DEMO! Colored Water http://www.youtube.com/watch?v=7xWWowXtuvA

Atmospheric Movement MOSTLY CAUSED BY: Temperature differences Pressure differences Coriolis Effect (due to Earth’s rotation)

HIGH Pressure = HAPPY weather A HIGH PRESSURE system occurs where the air mass above the Earth is denser than in surrounding areas, and therefore exerts a higher force or pressure. In a high pressure system you have dense air moving downwards and pushing down at the surface. When the surface air is being pushed down from the air above it spreads outwards, which is why we generally have fair weather. HIGH Pressure = HAPPY weather

LOW Pressure = LOUSY weather A LOW PRESSURE system occurs when air is dragged inwards and being pulled upward. As the warm humid air spirals upwards, it cools and clouds form. Low pressure systems are typically associated with cold and sometimes stormy weather. In winter, the clouds may even be thick enough to produce snow. LOW Pressure = LOUSY weather

Air Pressure Demos! Air Flow from High to Low! Acting out movement from high to low pressure (or video of a crowd or elevator http://www.youtube.com/watch?v=ZcK3Avl4KgU ) Balloon in a bottle http://www.youtube.com/watch?v=Q3owA2hGMzE Cloud in a Bottle http://www.youtube.com/watch?v=YUdR9xESD64 Air Flow from High to Low!

Global Winds A series of wind belts circles the earth. Between the wind belts are calm areas where air is rising or falling. If the earth did not rotate, global winds would blow in a straight line from the poles to the equator. The earth’s rotation causes the winds to curve. The curving of the winds is called the Coriolis Effect.

Global Wind Patterns The surface winds of each hemisphere are divided into 3 wind belts: Polar Easterlies: From 60-90 degrees latitude. Prevailing Westerlies: From 30-60 degrees latitude Tropical Easterlies: From 0-30 degrees latitude (aka Trade Winds).

Jet Streams Jet Streams function as steering currents for air masses and as zonal boundaries for sharp differences in temperature. Jets are something like "rivers of air" found at high altitudes and noted for their high speeds. Typical positions of two jet streams are shown in this diagram

  Weather fronts are the boundaries between air masses with different characteristics such as temperature, humidity, and air pressure. An air mass is a large parcel of air with roughly the same temperature, humidity, or pressure throughout. Different air masses tend not to mix. The clashing of two or more air masses is what causes severe storms. The front is literally the “front end” of an air mass. Movement of a front will depend largely on the conditions inside the air mass. Air masses tend to be either moist (maritime) or dry (continental) in humidity content. Temperatures are either cold (polar) or warm (tropical). The weather map symbols used for fronts are indicated above.

Four Types of Fronts Cold Fronts  A cold front forms when cold air moves underneath warm air, forcing the warm air to rise. 

Cold Front On Weather Map How can you tell which direction the front it moving from the map?

What kind of weather forms at a warm front? Four Types of Fronts Warm Fronts         - A warm front forms when warm air moves over cold air. What kind of weather forms at a warm front?

Warm Front On Weather Map How can you tell which direction the front it moving from the map?

Stationary Fronts     A stationary front occurs when warm and cool air meet and neither mass has the force to move the other. They remain stationary and can bring many days of clouds which, can produce rain, snow, or fog.

Occluded Fronts An occluded front occurs a warm air mass gets caught between two cold air masses. The two cold air masses push the warm air upward and they meet in the middle. The temperature drops as the warm air mass is occluded, or “cut off” from the ground and pushed upward. Occluded fronts can bring strong winds and heavy precipitation.

Reading Weather Maps http://0.tqn.com/d/weather/1/0/B/-/-/-/weathersymbolssummary.jpg

AIR MASSES & FRONT MOVEMENT Movement of a front will depend largely on the conditions inside the air mass. Air masses tend to be either moist (Maritime) or dry (Continental) in humidity content. Temperatures are either cold (polar) or warm (tropical). Continental – located over large land masses Maritime – located over the ocean Polar – poleward of 60 degrees latitude Tropical – located within about 25 degrees of the equator

Role of the Ocean Slowly absorbs and slowly releases heat energy helping keep Earth’s temperatures relatively stable Oceans heat or cool the air above them and transport heat around the globe in currents. Hurricanes form over warm ocean water, drawing their energy from the water’s heat.

http://www.weatherwizkids.com/weather-hurricane.htm

What Happens On Land? Landfall Hurricane Patricia After a few hours over land, a hurricane will weaken rapidly. WHY? Without the moisture and heat sources provided by the ocean, the storm can no longer produce thunderstorms near the eye. Without this convection, the storm's energy dissipates. Hurricane Katrina