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  1. 1. Weather Part 1 Temperature
  2. 2. Introduction to weather <ul><ul><li>Weather </li></ul></ul><ul><ul><ul><li>Is the short term condition of the atmosphere at any location </li></ul></ul></ul><ul><ul><ul><li>It is made up of the connection and relationship of </li></ul></ul></ul><ul><ul><ul><ul><li>Temperature </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Humidity </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Air pressure </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Wind </li></ul></ul></ul></ul>
  3. 3. Temperature Introduction <ul><ul><li>at any given place temperature is connected to the heat energy present in the atmosphere at that location </li></ul></ul><ul><ul><li>Solar radiation is the amount and how long the sun is on a particular location and how strong it is. </li></ul></ul><ul><ul><li>Therefore anything that changes solar radiation will also change the air temperature </li></ul></ul>
  4. 4. What are factors that can effects solar radiation ? <ul><ul><li>The following are factors that can change the amount of solar radiation a place has </li></ul></ul><ul><ul><ul><li>The angle that solar radiation hits the Earth </li></ul></ul></ul><ul><ul><ul><ul><li>this changes throughout the day because of the Earth rotation </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Solar radiation is only present during the day </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><li>similar changes also happen when the Earth moves around the sun </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>we call these slower changes seasons </li></ul></ul></ul></ul></ul><ul><ul><ul><li>number of hours of solar radiation during the day </li></ul></ul></ul><ul><ul><ul><li>the reflection </li></ul></ul></ul><ul><ul><ul><li>refraction </li></ul></ul></ul><ul><ul><ul><li>absorption of solar radiation </li></ul></ul></ul><ul><ul><ul><ul><li>for example clouds block and absorb the amount and intensity of the sun </li></ul></ul></ul></ul><ul><ul><ul><li>and the type of surface (ex: water and land) </li></ul></ul></ul>
  5. 5. How do we measure air temperature? <ul><ul><li>Temperature is measured with thermometers </li></ul></ul><ul><ul><ul><li>Works on a simple principle </li></ul></ul></ul><ul><ul><ul><ul><li>Matter expands when heated and contracts as it cools. </li></ul></ul></ul></ul><ul><ul><li>There are many scales of measuring temperature that are named after the people who made them up </li></ul></ul><ul><ul><ul><li>Celsius </li></ul></ul></ul><ul><ul><ul><li>Fahrenheit </li></ul></ul></ul><ul><ul><ul><li>Kelvin </li></ul></ul></ul><ul><ul><li>We use in the USA Fahrenheit the rest of the world uses Celsius </li></ul></ul><ul><ul><li>Meteorologist ( people who study weather ) use a thermograph as a thermometer </li></ul></ul>
  6. 6. Weather Part 2 Air Pressure
  7. 7. Introduction <ul><ul><li>Air is a mixture of different gases </li></ul></ul><ul><ul><li>Gas consists (made up of) many different tiny molecules that move around rapidly and are far apart from each other. </li></ul></ul><ul><ul><ul><li>They are kept contained either by a container or in the case of the atmospheres by the Earth’s Gravity </li></ul></ul></ul><ul><ul><li>Gases put pressure on the surfaces that they are in contact with. </li></ul></ul><ul><ul><li>In the case of air pressure this pressure is due to the gas particles bumping into the surface </li></ul></ul><ul><ul><ul><li>Since they move rapidly in all direction they balance out this pressure in all directions </li></ul></ul></ul>
  8. 8. How does air pressure help us forecast weather <ul><ul><li>You cant sense air pressure like you can with temperature </li></ul></ul><ul><ul><li>Nor can you forecast the weather based on the air pressure in a location </li></ul></ul><ul><ul><li>BUT since we have isoclines of the air pressure, we can study the changes of the air pressure and the different masses and temperatures that come with it. </li></ul></ul><ul><ul><ul><li>Rising pressure usually means fair weather </li></ul></ul></ul><ul><ul><ul><li>Low Pressure usually means an approach of a storm </li></ul></ul></ul>
  9. 9. How is air pressure measured? <ul><li>We use a barometer to measure air pressure. </li></ul><ul><ul><ul><ul><li>there are two common barometers used </li></ul></ul></ul></ul><ul><li>1. Mercury Barometer </li></ul><ul><li>2. Aneroid barometer </li></ul><ul><li>air pressure is measured based on units of force per a unit area </li></ul><ul><ul><ul><ul><ul><li>atmosphere (atm) is the average air pressure at sea level </li></ul></ul></ul></ul></ul>
  10. 10. Mercury Barometer <ul><li>air pressure forces liquid mercury up a tube </li></ul><ul><li>the more pressure the higher the mercury level will be </li></ul><ul><li>we usually name the number with inches or millimeters attached to the number </li></ul>
  11. 11. Aneroid Barometer <ul><li>aneroid means no liquid </li></ul><ul><li>it is a can with a spring scale on it </li></ul><ul><li>the amount of pressure on the sides of the can will either push down or loosen the spring scale </li></ul>
  12. 12. Weather Part 3 Wind
  13. 13. Air Movements <ul><ul><li>The reason why air circulates is because of density differences </li></ul></ul><ul><ul><ul><li>How thick the air is. </li></ul></ul></ul>
  14. 14. Air Currents <ul><ul><ul><li>Air currents are the rising and sinking vertical movements of the air </li></ul></ul></ul><ul><ul><ul><li>When these air currents sink and they reach the earth’s surface it does spread out horizontally. When the rising air expands it also spreads out horizontally. </li></ul></ul></ul>
  15. 15. <ul><ul><ul><li>When these air currents expand horizontally it forms wind. </li></ul></ul></ul><ul><ul><ul><ul><li>Wind is described by </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Speed </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Direction </li></ul></ul></ul></ul></ul>
  16. 16. <ul><li>is measured by an instrument called an Anemometer. </li></ul><ul><ul><ul><li>An Anemometer is 3-4 cups mounted on an axis that is attached to a compass. </li></ul></ul></ul><ul><ul><ul><li>The wind moves the cups causing the axis to spin. </li></ul></ul></ul><ul><ul><ul><li>The speed of the axis’s movements depends on the speed of the wind. </li></ul></ul></ul><ul><ul><ul><li>Wind Speed is measured by knots </li></ul></ul></ul><ul><ul><ul><ul><li>1 knot= 1.15 miles an hour </li></ul></ul></ul></ul>
  17. 17. <ul><li>Measured by a wind vane </li></ul><ul><ul><ul><li>A wind vane is a pointer on an axis that is also attached to a compass </li></ul></ul></ul><ul><ul><ul><li>The tail of the pointer is larger than the tip </li></ul></ul></ul><ul><ul><ul><li>This makes sure more pressure is put on the tail </li></ul></ul></ul><ul><li>Therefore it will point to the direction that the wind is coming </li></ul>
  18. 18. Weather Part 4 Humidity
  19. 19. Introduction to humidity <ul><ul><ul><li>Is the amount of Moisture in the air </li></ul></ul></ul><ul><ul><ul><li>IT IS NOT a liquid water in the air but rather it is water vapor (gas) </li></ul></ul></ul><ul><ul><ul><ul><li>water vapor is a colorless, odorless gas that enters the atmosphere when liquid water evaporates or ice sublimes ( changes straight from solid to gas) </li></ul></ul></ul></ul>
  20. 20. Humidity is Important <ul><ul><ul><li>Humidity is a very important weather factor because the water vapor in the air is what condenses to form </li></ul></ul></ul><ul><ul><ul><ul><li>cloud </li></ul></ul></ul></ul><ul><ul><ul><ul><li>fogs </li></ul></ul></ul></ul><ul><ul><ul><ul><li>precipitation </li></ul></ul></ul></ul>
  21. 21. Changes of water <ul><ul><ul><li>Water molecules are always changing from the three forms of matter </li></ul></ul></ul><ul><ul><ul><ul><li>solid </li></ul></ul></ul></ul><ul><ul><ul><ul><li>liquid </li></ul></ul></ul></ul><ul><ul><ul><ul><li>gas </li></ul></ul></ul></ul><ul><ul><ul><li>So therefore it looks like this </li></ul></ul></ul><ul><li>Ice Water </li></ul><ul><li>Water Vapor </li></ul>
  22. 22. How does water enter the atmosphere? <ul><ul><li>Most water enters the atmosphere from the form of liquid to gas </li></ul></ul><ul><ul><ul><li>called evaporation </li></ul></ul></ul><ul><ul><li>or ice to gas </li></ul></ul><ul><ul><ul><li>called sublimation </li></ul></ul></ul>
  23. 23. How does water leave the atmosphere? <ul><li>Condensation </li></ul><ul><ul><ul><ul><li>Water forming and leaving the atmosphere </li></ul></ul></ul></ul><ul><li>(We will talk later why water falls) </li></ul><ul><ul><li>Deposition </li></ul></ul><ul><ul><ul><li>Is when the vapor form into solid crystal without turning into water first </li></ul></ul></ul>
  24. 24. Point of Information <ul><li>This constant flow of water molecules throughout these phrases results in the change of humidity </li></ul>
  25. 25. Most of the change is between atmosphere and hydrosphere <ul><ul><ul><li>The molecule of water from the hydrosphere gain energy from sunlight and surroundings may become energetic enough to escape the liquid phrase and turn into water vapor </li></ul></ul></ul><ul><ul><ul><li>When water vapor molecule come in contact with the hydrosphere they sometimes get attached and stay there </li></ul></ul></ul><ul><ul><ul><li>it is a two way street. </li></ul></ul></ul>
  26. 26. Evaporation <ul><ul><ul><li>Is when the molecules get enough energy and form into water vapor in the atmosphere </li></ul></ul></ul><ul><ul><ul><ul><li>at higher temperatures molecules have more energy so more molecules will have the energy to escape and form into vapor </li></ul></ul></ul></ul><ul><li>HIGHER TEMP MORE EVAPORATE </li></ul>
  27. 27. Condensation <ul><li>Is when the water vapor molecules form a liquid and attach themselves onto the surface </li></ul><ul><li>This depends on how densely populated the molecules are. The more populated in a small area the more will attach themselves onto the surface </li></ul><ul><ul><ul><li>like being squeezed out of an elevator </li></ul></ul></ul>
  28. 28. Net evaporation and net condensation <ul><ul><ul><li>Net evaporation </li></ul></ul></ul><ul><ul><ul><ul><li>is when there is more molecules leaving the surface than there are attaching to the surface </li></ul></ul></ul></ul><ul><ul><ul><li>Net condensation </li></ul></ul></ul><ul><ul><ul><ul><li>is when there is more molecules leaving the atmosphere and attaching to the surface than those leaving the surface </li></ul></ul></ul></ul>
  29. 29. They go in a circle <ul><ul><ul><ul><li>if there is a net evaporation the more water vapor there is in the air which means the denser it will get and more vapor gets pushed out and stuck to the surface </li></ul></ul></ul></ul><ul><ul><ul><ul><li>eventually a point is reached where their is an equilibrium </li></ul></ul></ul></ul><ul><ul><ul><ul><li>If the temperature drops suddenly then the water vapor will be more then the equilibrium </li></ul></ul></ul></ul>
  30. 30. Relative Humidity /Absolute humidity <ul><ul><ul><li>The amount of water vapor in the air is usually referred to absolute or relative humidity </li></ul></ul></ul>
  31. 31. Absolute Humidity <ul><ul><li>is the amount of vapor found 1 cubic meter of the air. </li></ul></ul><ul><ul><ul><ul><li>since it is very hard to isolate the water vapor in the air in order to measure it absolute humidity is very rarely measured </li></ul></ul></ul></ul>
  32. 32. Relative humidity <ul><li>is the ratio of water vapor present in the atmosphere to the water vapor present when evaporation and condensation are equal at that temperature X 100 </li></ul>Water vapor in atmosphere Relative humidity = ------------------------------------------------------ X100 Water vapor in atmosphere at equilibrium
  33. 33. Relative humidity <ul><li>relative humidity is a way to of comparing the flows of water molecules leaving and arriving at a surface </li></ul><ul><li>it is useful in predicting how the air will feel to a person AND whether evaporation or condensation would more likely occur </li></ul>
  34. 34. Point of Information <ul><li>Relative humidity 20% means that the air only has 20% of the water vapor it would have during equilibrium </li></ul><ul><li>relative humidity of 100% means that the air contains 100% of the water vapor it has during equilibrium </li></ul>
  35. 35. Relative humidity con’t <ul><ul><li>The higher the relative humidity the (stickier) the air will feel. </li></ul></ul><ul><ul><li>If the relative humidity is 100% it does not mean that the air is 100% water vapor it still has oxygen and nitrogen etc…….. </li></ul></ul>
  36. 36. High relative humidity <ul><ul><li>Means that the WV in the air is close to it’s equilibrium amount </li></ul></ul><ul><ul><li>A decrease in temperature (will also decrease the temperature amount needed for condensation) will decrease equilibrium amount needed for condensation which makes fog, clouds, or precipitation </li></ul></ul>
  37. 37. Dew point <ul><ul><li>This leads us to dew point </li></ul></ul><ul><li>Dew point is the temperature at which water vapor in the air will begin to condense into liquid water </li></ul><ul><li>THIS IS THE TEMPRATURE AT WHICH THE AMOUNT OF WATE VAPOR IN THE AIR EQUALS THE AMOUNT OF EQUALIBRUIM FOR THAT TEMP </li></ul>
  38. 38. How is humidity measured? <ul><li>There are two different tools used to measure humidity </li></ul><ul><ul><li>Hygrometer </li></ul></ul><ul><ul><li>Psychrometer </li></ul></ul>
  39. 39. Hygrometer <ul><li>Consists of strands of human hair attached to a pointer </li></ul><ul><li>Human hair grows slightly as humidity increases </li></ul><ul><li>and shrinks when it decreases </li></ul><ul><ul><li>The pointer changes position based on the length of the hair </li></ul></ul>
  40. 40. Psychrometer <ul><ul><li>Is made of two thermometers </li></ul></ul><ul><ul><li>Dry bulb </li></ul></ul><ul><ul><li>- The bulb is kept dry </li></ul></ul><ul><ul><li>Wet bulb – the bulb is kept wet by a covered cloth wick soaked in water </li></ul></ul><ul><ul><ul><ul><li>Evaporation from the wet wick causes cooling because the fastest molecules in liquid water are the ones that have enough energy to escape </li></ul></ul></ul></ul><ul><ul><ul><ul><li>The slower molecules have a lower average energy. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Therefore the liquid temperature decreases due to the loss of energy. </li></ul></ul></ul></ul>
  41. 41. <ul><ul><li>This cooling effect is KEY to measuring relative humidity </li></ul></ul><ul><ul><li>The lower the relative humidity the more water can evaporate from the wet bulb and the more the thermometer is cooled. </li></ul></ul><ul><ul><li>The Dry Bulb Temp. remains unchanged. </li></ul></ul><ul><ul><ul><li>Therefore the difference between the dry bulb and wet bulb temperature is directly related to the relative humidity of the air. </li></ul></ul></ul>
  42. 42. How do we figure out Relative humidity? <ul><ul><li>You subtract the dry bulb e from the wet bulb temp </li></ul></ul><ul><li>Find in the table where the dry bulb temp (right side) and the difference temp # meet </li></ul><ul><ul><li>That number is your relative humidity percent </li></ul></ul>
  43. 43. How do we figure out the Dew Point? <ul><li>The difference between the wet and dry bulb is also directly related to dew point. </li></ul><ul><li>The higher the relative humidity the closer the air is being filled to capacity. </li></ul><ul><li>Cooling air decreases the capacity to hold water </li></ul><ul><li>So we will use a different table </li></ul><ul><li>you will figure out the difference between Wet and dry </li></ul><ul><li>You will then see where it meets with the dry bulb temperature </li></ul><ul><li>That number at the intersection is the dew point in degrees of C. </li></ul>
  44. 44. Weather How do these variables relate to each other?
  45. 45. What are the relationships amongst the variables – Introduction <ul><ul><li>The atmospheric variables that we learned previously are interrelated (there is a direct correlation) </li></ul></ul><ul><ul><li>A change in one would probably affect another </li></ul></ul><ul><ul><li>This is best understood even though we have the kinetic theory of gases </li></ul></ul>
  46. 46. Kinetic gas theory <ul><li>Gas is made out of tiny, individual that do not interact with each other except when they collide </li></ul><ul><li>The molecules are far apart and constantly moving </li></ul><ul><li>Temperature of gas is proportional to the speed in which it is traveling. </li></ul>
  47. 47. The relationship between air temperature and air pressure
  48. 48. What we already know <ul><ul><li>Air pressure is the result of the forces of gas colliding with each other and surfaces </li></ul></ul><ul><ul><li>Air temperature depends on the speed of gas molecules </li></ul></ul>
  49. 49. If there was a change in temperature <ul><li>Air pressure and temperature are related because both involve the motion of the molecules </li></ul><ul><li>You would therefore think…………. </li></ul><ul><ul><li>The higher the temperature the more force they collide with higher the air pressure </li></ul></ul><ul><ul><li>Therefore it would make sense the higher the temperature the higher the air pressure. HOWEVER……….. </li></ul></ul>
  50. 50. THIS IS FALSE……. <ul><li>This is not true because the atmosphere does not have walls rather its has open space </li></ul><ul><li>When the atmosphere’s temperature increases the molecules move faster and collide more vigorously </li></ul><ul><li>As a result the molecules will bounce father away from each other at the atmosphere expands </li></ul><ul><li>Even though the molecules are moving faster there are fewer collisions because they are farther apart. </li></ul>
  51. 51. So what is the relationship is the temorature changes <ul><li>THEREFORE WE SEE A DECREASE IN AIR PRESSURE WHEN THE AIR TEMPRATURE INCREASES. </li></ul>
  52. 52. Let us say there is a change in the air pressure what would happen to the air temperature? <ul><li>The main cause of change in the air pressure is the rising or falling of the air in convection currents. </li></ul><ul><ul><li>convection currents are fluid movements set in motion by fluid density changes </li></ul></ul><ul><li>So if a group of air sinks there would be less (more density) if the group of air rises there will be more room to expand. </li></ul><ul><li>Any gas that is allowed to expand because the surrounding expanded will become cooler </li></ul><ul><li>Any gas that shrinks in space will become warmer </li></ul>
  53. 53. TIME OUT Adiabatic changes <ul><li>Are the rise and fall of temperature that has NOTHING to do with heat being added from outside forces? </li></ul>
  54. 54. So therefore…………… <ul><li>SO if the gas is rising and is allowed to expand then their will be more room form the molecules to live in and less collision would occur. </li></ul><ul><li>But if the space for the air is reduced than their will be more collisions and higher temperatures </li></ul>
  55. 55. The results are <ul><li>IF AIR PRESSURE GOES UP- TEMP GOES UP </li></ul><ul><li>IF PRESSURE GOES DOWN TEMP WILL GO DOWN </li></ul>
  56. 56. The relationship between air pressure and humidity
  57. 57. <ul><ul><li>The greater the mass of molecules the more collisions will occur </li></ul></ul><ul><ul><li>The mass of elements in the air depends on the mass composition of the air </li></ul></ul><ul><ul><li>The air as we know is mostly nitrogen and oxygen they are both denser then water vapor molecules </li></ul></ul><ul><ul><ul><li>The more water vapor in the air takes the place of the nitrogen and oxygen the lighter the force of air pressure it will be </li></ul></ul></ul>
  58. 58. <ul><ul><li>SO THE HIGHER THE HUMIDITY THE LOWER THE AIR PRESSURE </li></ul></ul><ul><ul><li>THE LOWER THE HUMIDITY THE HIGHER THE AIR PRESSURE </li></ul></ul><ul><ul><ul><li>When it is very humid outside and then it rains you can feel the release of air pressure in the air. </li></ul></ul></ul>
  59. 59. Air temperature and humidity
  60. 60. <ul><ul><li>We know the higher the air temperature the more water vapor is going to be in the air before equilibrium </li></ul></ul><ul><ul><ul><li>Therefore warmer air contains more vapor than cooler air </li></ul></ul></ul><ul><ul><ul><li>At any given temp a fixed amount of vapor will be present in the air when we reach equilibrium </li></ul></ul></ul><ul><ul><ul><li>At a higher temperature more of the molecules will be able to break free and become vapor </li></ul></ul></ul><ul><ul><ul><ul><li>As the vapor becomes more crowded with molecules it is more likely that it will condense </li></ul></ul></ul></ul><ul><ul><ul><li>Therefore the water vapor warm air will increase until a new equilibrium status is reached 9depends on the Temp.) </li></ul></ul></ul><ul><ul><ul><li>The amount of vapor in the air is greater in temp than lower temps </li></ul></ul></ul>
  61. 61. <ul><ul><li>Since the amount of water vapor in the air at equilibrium changes with temperature = the relative humidity is also affected by the temperature </li></ul></ul><ul><ul><li>So if the temperature increases that will cause the equilibrium mark to increase which will make the relative humidity decrease. </li></ul></ul><ul><ul><ul><li>Because the higher the temperature and equilibrium mark. The more vapor is needed to raise the humidity. </li></ul></ul></ul>
  62. 62. <ul><ul><li>The reverse is true as well. If the temperature decreases the equilibrium mark will decrease and the amount of vapor in the air remains the same, relative humidity will increase. </li></ul></ul><ul><ul><li>As we know, as the temp decreases it eventually reaches the dew point. </li></ul></ul><ul><ul><ul><li>At that point the relative humidity is 100 percent </li></ul></ul></ul><ul><ul><li>If the temp decreases more, than condensation will form at a faster rate. Than evaporation until equilibrium is reestablished. </li></ul></ul><ul><ul><li>Therefore, as temperature reaches dew point precipitation becomes more likely. </li></ul></ul>
  63. 63. Air Pressure and Wind
  64. 64. General rule……. <ul><ul><li>Winds blow from regions (places) of high air pressure to regions of low pressure. </li></ul></ul><ul><ul><ul><li>IN OTHER WORDS AIR BEING PUSHED BY HIGH AIR PRESSURE WILL ADVANCE AGAINST THE PERSON SIR BEING PUSHED WITH LOW AIR PRESSURE. </li></ul></ul></ul><ul><ul><li>The net movement of air is from HIGH pressure to LOW Pressure </li></ul></ul>
  65. 65. Land and sea breezes <ul><ul><ul><li>Land and sea show the air movement from high to low pressure very clearly </li></ul></ul></ul><ul><ul><ul><ul><li>difference of air pressure between adjacent (next to ) places occur when ever land and water meet </li></ul></ul></ul></ul>
  66. 66. During the day <ul><li>SO DURING THE DAY when sunlight is out. The land gets hotter than the sea </li></ul><ul><li>Therefore land during the day will have a higher air temperature than the water during the day. </li></ul><ul><li>Since warm air has less pressure than cool air the pressure over the land will be cooler </li></ul><ul><li>THEREFORE wind during the day will go from the water inwards to the land. </li></ul><ul><li>This wind is called SEA BREEZE </li></ul>
  67. 67. At Night…….. <ul><li>Land cools faster than water and therefore will have more pressure than the water. </li></ul><ul><li>The wind will therefore will blow from the land out to sea. </li></ul><ul><li>This is called a land breeze </li></ul>
  68. 68. <ul><ul><ul><li>Differences in pressure between regions also effect on a global scale </li></ul></ul></ul><ul><ul><ul><li>Unequal heating of the atmosphere at different latitudes cause three large atmospheric convention cells to form in the northern and southern hemisphere </li></ul></ul></ul><ul><ul><ul><li>Rising air in these convection cells produces LOW pressure belts that circle the earth at the equator, artic circle(60) and the Antarctic circle (90) </li></ul></ul></ul>
  69. 69. <ul><ul><ul><li>Sinking air makes high pressure belts at the poles , tropic of cancer (30) and Capricorn (30 S) </li></ul></ul></ul><ul><ul><ul><li>THEREFORE A SERIES OF ALTERNATING HIGH AND LOW PRESSURE BELTS CIRCLE EARTH, GIVING RISE TO A SERIES OF GLOBAL WIND BELTS AS AIR MOVES FROM REGIONS OF HIGH PRESSURE TO REGIONS OF LOW PRESSURE </li></ul></ul></ul><ul><ul><ul><ul><li>(look at the wind belt diagram) the global wind that blow from high pressure belts at 30 N and south towards low pressured equator </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>This is called trade winds. </li></ul></ul></ul></ul></ul>
  70. 70. Coliotis Effect <ul><ul><li>is the deflection of motion due to the rotation of the earth </li></ul></ul><ul><ul><ul><li>This causes these large scale winds to curve to the right in the Northern hemisphere </li></ul></ul></ul><ul><ul><ul><li>They blow North east </li></ul></ul></ul><ul><ul><ul><li>This also causes the wind to curve to the left in the Southern Hemisphere </li></ul></ul></ul><ul><ul><ul><li>They blow South east </li></ul></ul></ul>
  71. 71. <ul><ul><li>Winds blow from regions (places) of high air pressure to regions of low pressure. </li></ul></ul><ul><ul><ul><li>IN OTHER WORDS AIR BEING PUSHED BY HIGH AIR PRESSURE WILL ADVANCE AGAINST THE PERSON SIR BEING PUSHED WITH LOW AIR PRESSURE. </li></ul></ul></ul><ul><li>The net movement of air is from HIGH pressure to LOW Pressure </li></ul>
  72. 72. <ul><ul><ul><li>Global winds also blow from the high pressure belts at 30 S and N towards the low pressure belts at the 60 N and S </li></ul></ul></ul><ul><ul><ul><ul><li>They are called Prevailing winds </li></ul></ul></ul></ul><ul><ul><ul><ul><li>The colitis effect causes these winds to blow southwest in the north and South east in the South </li></ul></ul></ul></ul>
  73. 73. <ul><ul><li>The global winds that blow from regions over the poles towards the low pressure regions of 60 N and S are known as polar easterlies. </li></ul></ul><ul><li>The coriolis effect causes these winds to blow from the northeast in the north and southeast in the south </li></ul>
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