1. The Earth’s Atmosphere

2. Layers of Air There are 4 basic layers of air: There are 4 basic layers of air: 1. Troposphere 1. Troposphere 2. Stratosphere 2. Stratosphere 3. Mesosphere 3. Mesosphere 4. Thermosphere 4. Thermosphere

4. Troposphere The is where all weather takes place; it is the region of rising and falling packets of air. The _______________ is where all weather takes place; it is the region of rising and falling packets of air. The air pressure at the top of the troposphere is only 10% of that at sea level (0.1 atmospheres). The air pressure at the top of the troposphere is only 10% of that at sea level (0.1 atmospheres).

5. Troposphere The troposphere starts at the Earth's and extends 8 to 14.5 kilometers high (5 to 9 miles). The troposphere starts at the Earth's _______________ and extends 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is the most dense. This part of the atmosphere is the most dense. As you climb higher in this layer, the temperature drops from about 17 to -52 degrees Celsius. As you climb higher in this layer, the temperature drops from about 17 to -52 degrees Celsius.

6. Stratosphere The starts just above the troposphere and extends to 50 kilometers (31 miles) high. The _______________ starts just above the troposphere and extends to 50 kilometers (31 miles) high. Above the troposphere is the stratosphere, where air flow is mostly. Above the troposphere is the stratosphere, where air flow is mostly _______________. The thin ozone layer in the upper stratosphere has a high concentration of, a particularly reactive form of oxygen. The thin ozone layer in the upper stratosphere has a high concentration of _______________, a particularly reactive form of oxygen.

7. Stratosphere The thin ozone layer in the upper stratosphere has a high concentration of ozone, a particularly reactive form of. The thin ozone layer in the upper stratosphere has a high concentration of ozone, a particularly reactive form of _______________. This layer is primarily responsible for absorbing the from the Sun. This layer is primarily responsible for absorbing the _______________from the Sun. There is considerable recent concern that manmade fluorocarbon compounds may be depleting the ozone layer There is considerable recent concern that manmade fluorocarbon compounds may be depleting the ozone layer

8. Mesosphere The starts just above the stratosphere and extends to 85 kilometers (53 miles) high. The _______________ starts just above the stratosphere and extends to 85 kilometers (53 miles) high. In this region, the temperatures again fall as low as -93 degrees Celsius as you increase in altitude. In this region, the temperatures again fall as low as -93 degrees Celsius as you increase in altitude.

9. Thermosphere (Ionosphere) The is very thin, but it is where aurora take place, and is also responsible for absorbing the most energetic from the Sun, and for reflecting radio waves, thereby making long-distance radio communication possible. The _______________ is very thin, but it is where aurora take place, and is also responsible for absorbing the most energetic _______________ from the Sun, and for reflecting radio waves, thereby making long-distance radio communication possible.

10. Thermosphere The thermosphere starts just above the mesosphere and extends to 600 kilometers (372 miles) high. The thermosphere starts just above the mesosphere and extends to 600 kilometers (372 miles) high. Temperatures in this region can go as high as 1,727 degrees Celsius. Chemical reactions occur much faster here than on the surface of the Earth. Temperatures in this region can go as high as 1,727 degrees Celsius. Chemical reactions occur much faster here than on the surface of the Earth. This layer is known as the. This layer is known as the ______________________________.

11. Composition of the Atmosphere The atmosphere is primarily composed of The atmosphere is primarily composed of – - 78% –_______________ - 78% – - 21% –_______________ - 21% – - 1%. –_______________ - 1%.

12. Winds Jet Stream Jet Stream

13. Once air begins moving, the Earth's rotation causes it to follow a curved path; this is referred to as the. Once air begins moving, the Earth's rotation causes it to follow a curved path; this is referred to as the _______________.

14. Jet Stream The term "jet stream" is often used to refer to the high in the atmosphere - above about 20,000 feet. The term "jet stream" is often used to refer to the ________________________ high in the atmosphere - above about 20,000 feet. These winds help determine the locations of areas of high and low air pressure at the Earth's surface. These winds help determine the locations of areas of high and low air pressure at the Earth's surface.

15. A jet stream is "a relatively narrow river of very strong winds. A jet stream is "a relatively narrow river of very strong _______________ winds. Jet streams form along the upper air boundaries of large masses of warm and cold air. Jet streams form along the upper air boundaries of large masses of warm and cold air.

16. During major cold outbreaks over the USA, the jet stream often dives south - staying above the warm-cold boundary - sometimes moving well over the Gulf of Mexico. During major cold outbreaks over the USA, the jet stream often dives south - staying above the warm-cold boundary - sometimes moving well over the Gulf of Mexico. During unusually mild winter weather and during the summer, the jet stream retreats northward into Canada. During unusually mild winter weather and during the summer, the jet stream retreats northward into Canada.

17. Jet Stream Patterns

20. Clouds Cirrus Cirrus Stratus Stratus Cumulus Cumulus Nimbus - prefix Nimbus - prefix

21. Cirrus Clouds Cirrus clouds are thin, wispy clouds that usually form above 18,000 feet. Cirrus clouds are thin, wispy clouds that usually form above 18,000 feet. Cirrus clouds generally move from to across the sky and usually "point" to fair weather. Cirrus clouds generally move from _______________ to _______________ across the sky and usually "point" to fair weather.

22. Cirrus clouds are thin because they form in the higher levels of the atmosphere where little water vapor is present. Cirrus clouds are thin because they form in the higher levels of the atmosphere where little water vapor is present.

23. Cirrus Clouds

24. Stratus Clouds - Fog

25. Fog forms when the air cools to a point at which water vapor in it begins to condense into tiny water droplets. Fog forms when the air cools to a point at which water vapor in it begins to condense into tiny water droplets. The temperature at which water vapor will begin condensing from the air at any particular time is called the "." The temperature at which water vapor will begin condensing from the air at any particular time is called the "_______________."

26. Stratus clouds are uniform gray clouds that usually cover the entire sky. Stratus clouds are uniform gray clouds that usually cover the entire sky. Stratus clouds look like a layer of fog that never reaches the ground. Stratus clouds look like a layer of fog that never reaches the ground. Precipitation rarely falls from true stratus clouds, but light mist and drizzle can sometimes accompany stratus clouds. Precipitation rarely falls from true stratus clouds, but light mist and drizzle can sometimes accompany stratus clouds.

27. Stratus Clouds

28. Cumulus Clouds

30. Cumulus clouds form as water vapor condenses in strong, upward air currents above the earth's surface. Cumulus clouds form as water vapor condenses in strong, upward air currents above the earth's surface. These clouds usually have and. These clouds usually have _______________ and _______________.

31. Most cumulus clouds form below 6,000 feet and are relatively thin and associated with fair weather. Most cumulus clouds form below 6,000 feet and are relatively thin and associated with fair weather. When the atmosphere becomes unstable, and very strong, upward air currents form, cumulus clouds can grow into cumulus congestus, or. When the atmosphere becomes unstable, and very strong, upward air currents form, cumulus clouds can grow into cumulus congestus, or _______________.

32. If the atmosphere is unstable enough, cumulonimbus clouds, better known as thunderstorms, form. If the atmosphere is unstable enough, cumulonimbus clouds, better known as thunderstorms, form. Cumulus congestus and cumulonimbus clouds can tower from below 6,000 feet to greater than 50,000 feet. Cumulus congestus and cumulonimbus clouds can tower from below 6,000 feet to greater than 50,000 feet.

33. Cumulus Clouds

34. Other Cloud Types Contrails

35. Mammatus Clouds

36. These pouch-like clouds often form underneath a thunderstorm where cooler air sinks into warmer below the storm cloud. These pouch-like clouds often form underneath a thunderstorm where cooler air sinks into warmer below the storm cloud. clouds look threatening, but actually signal the weakening of a thunderstorm. _______________ clouds look threatening, but actually signal the weakening of a thunderstorm.

37. Precipitation Rain Rain Snow Snow Sleet Sleet Freezing Rain Freezing Rain Hail Hail

38. Rain

40. Snow

41. Sleet

42. Freezing Rain

43. Hail

46. Weather Thunderstorms Thunderstorms –Cumulus clouds, strong winds, heavy rain, lightning, and thunder. –Single Cell –Multi Cell –Supercell

47. Single Cell

48. Severe weather is limited to brief, isolated - Severe weather is limited to brief, isolated - –downbursts, small hail, heavy rain, and weak tornadoes –low degree of predictability of severe events –low to moderate danger to public –moderate to high danger to aviation.

49. Multicell

50. Multicell

51. Supercell

52. Supercell

53. Lightning - electrical discharge that travels between 2 oppositely charged surfaces (friction occurs between the raindrops and ice crystals as they are being pushed up and down in the clouds). _______________ - electrical discharge that travels between 2 oppositely charged surfaces (friction occurs between the raindrops and ice crystals as they are being pushed up and down in the clouds).

54. Lightning The upper portion of the clouds become positively charged and the lower portion becomes negatively charged. The upper portion of the clouds become positively charged and the lower portion becomes negatively charged. Eventually the charge in the lower portion of the clouds becomes great enough to pull away from the ground, making it positively charged. Eventually the charge in the lower portion of the clouds becomes great enough to pull away from the ground, making it positively charged. Difference is great enough, the electrical is discharged from the cloud to the ground. Difference is great enough, the electrical is discharged from the cloud to the ground.

55. Lightning Lightning follows the shortest path - striking the tallest or highest object. Lightning follows the shortest path - striking the tallest or highest object.

56. We hear thunder because lightning heats the air to more than 43,000 degrees, causing the air to quickly expand. The air then quickly cools after the flash, which causes it contract. We hear thunder because lightning heats the air to more than 43,000 degrees, causing the air to quickly expand. The air then quickly cools after the flash, which causes it contract. This quick expansion and contraction of air around the lightning starts air molecules moving back and forth, making sound waves, which we hear as. This quick expansion and contraction of air around the lightning starts air molecules moving back and forth, making sound waves, which we hear as _______________.

58. Tornado Intense storm with high winds that circle a small center of extremely low pressure. Intense storm with high winds that circle a small center of extremely low pressure. Form along cold fronts. Form along cold fronts. Spin. Spin _______________. - tornado over a body of water like a lake. _______________ - tornado over a body of water like a lake.

59. Tornado

60. Tornado

61. Tornado Dr. Theodore Fujita Dr. Theodore Fujita –Well known researcher. –Came up with the Fujita scale - F1, F2, F3, F4, F5 –Scale is based on the wind speed of a tornado.

62. Hurricane Cyclonic storms that develops over warm ocean water. (Get their energy from the water) Cyclonic storms that develops over warm ocean water. (Get their energy from the water) Western Pacific Ocean - Western Pacific Ocean - ______________ Indian Ocean - Indian Ocean - _______________ Named after females until the late 70’s. Named after females until the late 70’s.

63. Hurricanes

64. The seven main characteristics that define a hurricane, are: Hurricanes have no. Hurricanes have no _______________. Hurricane winds weaken with height Hurricane winds weaken with height The centers of hurricanes are warmer than their surroundings The centers of hurricanes are warmer than their surroundings Hurricanes and tropical systems form under weak high-altitude winds. Hurricanes and tropical systems form under weak high-altitude winds. Air sinks at the center of a hurricane Air sinks at the center of a hurricane Hurricanes' main energy source is the latent heat of condensation Hurricanes' main energy source is the latent heat of condensation Hurricanes weaken rapidly over land Hurricanes weaken rapidly over land

66. Tropical systems are classified into four categories according to its degree of organization and maximum sustained wind speed., tropical wave: Unorganized mass of thunderstorms, very little, if any, organized wind circulation. _______________, tropical wave: Unorganized mass of thunderstorms, very little, if any, organized wind circulation. : Has evidence of closed wind circulation around a center with sustained winds from 20-34 knots (23-39 mph). _______________ : Has evidence of closed wind circulation around a center with sustained winds from 20-34 knots (23-39 mph). : Maximum sustained winds are from 35-64 knots (40-74 mph). The storm is named once it reaches tropical storm strength. _______________: Maximum sustained winds are from 35-64 knots (40-74 mph). The storm is named once it reaches tropical storm strength. : Maximum sustained winds exceed 64 knots (74 mph). _______________: Maximum sustained winds exceed 64 knots (74 mph).