6.9B verify through investigations that thermal energy moves in a predictable pattern from warmer to cooler 6.5B recognize that a limited number of

Transcription

1 6.9B verify through investigations that thermal energy moves in a predictable pattern from warmer to cooler 6.5B recognize that a limited number of elements comprise the largest portion of oceans and atmosphere 8.10A recognize that the Sun provides the energy that drives convection within the atmosphere and oceans, producing winds and ocean currents

2 Due to the background color of this ppt, most of the notes you need to take are in yellow!

3 Sun heats the earth unevenly Land and water heat the air Temperature differences cause pressure differences Air travels in circular patterns called convection cells (cells are small convection currents) High pressure moves to low pressure

4 Do you know how a bicycle pump works?

5 When you pull the handle upwards air is pulled in through an intake valve and the piston is full of air. When you push back down on the handle, the air is pushed out of the piston, into the hose and out of the fill valve.

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7 The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity. A. It is mainly composed of a few limited elements: Nitrogen ~78% Oxygen ~21% Argon, Carbon, Neon, Helium, Hydrogen, & Krypton ~1%

8 B. It is a complex and dynamical, physical and chemical system. Dynamical: the processes of evaporation, condensation, precipitation Physical: the transfer of heat from the Sun to the Earth s surface Chemical: the transformation and production of gases, such as ozone through chemical reactions of atmospheric gases.

9 The troposphere is the atmospheric layer closest to the planet and contains the largest percentage (around 80%) of the mass of the total atmosphere. All weather phenomena occur within the troposphere

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11 Watch the wind move today!

12 Movement of air is caused by temperature or pressure differences Wind is the movement of air as a result of different air pressure The greater the pressure difference, the stronger the wind

13 Wind (air) always moves from high pressure to low pressure (this key, remember it!!!) Air moves because of an imbalance in the forces acting on the air molecules. Wind is the atmosphere's way of trying to bring the interaction of these forces into a balance; an equilibrium. Due to uneven heating of Earth and the differences in how the atmosphere heats versus how the land and water heat this imbalance is constantly changing so the balance is never achieved and the air molecules move, which is wind.

14 Wind also blows faster if there's nothing in its way, so winds are usually stronger over oceans or flat ground. Meteorologists can forecast the speed and direction of wind by measuring air pressure with a barometer.

15 Although wind blows from areas of high pressure to areas of low pressure, it doesn't blow in a straight line. That's because the earth is rotating. In the northern hemisphere, the spin of the earth causes winds to curve to the right (to the left in the southern hemisphere). This is called the Coriolis effect. So in the northern hemisphere, winds blow clockwise around an area of high pressure and counterclockwise around low pressure.

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17 Real-Life Application of Coriolis Effect Fast-moving objects such as airplanes and rockets are influenced by the Coriolis effect. Pilots must take the Earth s rotation into account when charting flights over long distances. This means most planes are not flown in straight lines, even if the airports are directly across the continent from each other. The line between Portland, Maine, and Portland, Oregon, for instance, is very long, and fairly straight. However, a plane flying from Portland, Oregon, could not fly in a straight line and land in Portland, Maine. Flying east, the Coriolis effect seems to bend to the right, in a southerly direction. If the Oregon pilot flew in a straight line, the plane would end up near New York or Pennsylvania.

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19 Local winds- generally move short distances and can blow from any direction. Global winds- are part of a pattern of air flow that moves across the Earth.

20 Land breezes and sea breezes occur because of the differences in heating of the land (a solid) and water (liquid) These differences create small convection currents

21 Warm Air Rises Air Cools Down Cold Air Sinks Wind Blows Toward Coast Warm Air Rises During the day, the land heats up more quickly than the sea. Above the land, warm air rises and the wind blows toward the coast. Air Cools Down Wind Blows Away from the Coast Cold Air Sinks At night, the land cools down quickly while the sea stays warm. Above the sea, warm air rises and the wind blows away from the coast.

22 During the day - Valley Breeze: The Sun warms the air on the slopes of the mountain faster than down in the valleys. This uneven heating results in areas of lower pressure at mountain tops The difference in pressure causes a breeze, which flows up from the valleys to the mountain tops

23 At night, the air on the mountain cools and moves into the valleys This is called the mountain breeze

24 Air travels in this circular pattern This pattern does not mean there is 1 or 2 really large currents on the Earth, but instead these currents are broken up into every 30 O of latitude These are called global wind patterns

25 The major global wind systems are the polar easterlies, the westerlies and the trade winds.

26 The names of the types of winds on the next few slides are in red. Then draw the direction of the winds, using arrows

27 Called trade winds because early sailors used the winds to sail from Europe to America Blow between 30 o latitude and the equator, in both hemispheres. Label the equator, and the trade winds. The wind movement arrows are done for you for this one

28 Blow between 30 o and 60 o latitudes in both hemispheres. Flows towards the poles. Helped ships return to Europe. Blows from west to east-- WESTERLIES Winds are turned toward the east by Coriolis effect Label the westerlies and draw arrows on your globe

29 Between the poles and 60 o latitudes. Form as cold air near poles sinks and flows back toward lower latitudes Coriolis shifts these winds to the west Wind goes from East to west EASTERLIES Label on your globe!

30 The trade winds of both hemispheres meet in a calm area around the equator known as the doldrums. Very little wind blows because the warm, less dense air results in an area of low pressure. The name means, dull or sluggish Usually between 5 north and 5 south of the equator

31 Between about 30 to 35 north and 30 to 35 south Air stops moving and sinks Contributes to deserts in this area

32 Tradition states that sailors gave the region the name "horse latitudes" because sailing ships; fearful of running out of food and water, sailors threw their horses and cattle overboard to save on provisions. (It's a puzzle why sailors would not have eaten the animals instead of throwing them overboard.)

33 A high altitude wind, about 7-16 km up (that s roughly 6-9 miles high) Airplanes fly at 35,000 feet or about 6 miles up These are narrow belts of high speed winds that blow from west to east If a pilot can use the jet stream to travel, they save on fuel and can go faster Two jet streams, polar and subtropical

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36 Most rainforests are near the equator because this is where the air is rising, creating clouds and rain.

37 Most deserts are at 30 o N and S Latitude because the air is sinking, drying it out.

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39 Since air is inside both the bottle and the balloon, is there already a certain pressure that you are starting off with? Also, the temperature of the air inside is room temperature. Think about WHY we are doing this! (What has this lesson been about?)

40 Show Integrity and use Principled behavior by cleaning what you have used! Pour water out of bowls and down the sink Wipe everything dry Place all materials back onto the tray Be back at your chair ready for dismissal