Understanding Weather: Solar Heating and Water Vapor Impact

1. Weather

2. 3/18/15 AIM: How does solar heating and water vapor in the atmosphere affect weather? DO NOW: How does weather affect your life? HOMEWORK: Finish all Vocabulary P.454 Figure 1“Identifying” P. 455 figure 2 “infer” P 456 “Reading check”

3. 3/19/15 AIM: How does solar heating and water vapor in the atmosphere affect weather? DO NOW: What factors affect the weather? HOMEWORK p.461 # 1-5

4. 3/23 AIM: How can clouds help us determine the weather? Do Now: Describe the type and shape of clouds on a rainy day and on a sunny day HOMEWORK: “Types of clouds” handout

5. What am I? You can’t see me, but you feel me, you can’t touch me, but I can touch you. I have been called the “Breathe of the Gods”, or the killer and giver of life, gentle and fierce, friendly and enemy, angry and happy. What am I? WIND

6. Weather is.... • The current state of the atmosphere...what is happening right now • The sun provides the energy that drives the Earth’s weather

7. Main points to remember as we learn about weather: • The sun warms the earth’s surface and therefore all the air above the surface • The earth is warmed most at the equator and least at the poles---why? • The air above land is warmed more quickly than air above water. • Warm air expands and rises, creating an area of low pressure; cold air is dense and sinks, creating an area of high pressure

8. Weather Factors • FACTORS • TEMPERATURE= the average motion of molecules ↑ TEMP= ↑movement of molecules= feels hot ↓ TEMP= ↓movement of molecules= feels cold

9. Air Pressure • Warm air= expanding or rising air= leaves behind Low pressure • Cold Air =sinking air= leaves an area of High pressure

10. Humidity and Relative Humidity The amount of water vapor present in the air Relative Humidity -is a measure of the amount of water vapor present in the air compared to the amount needed for saturation at a specific temperature Fig.4 page 457

11. Water in the Atmosphere: Humidity (detailed) Humidity: measure of the amount of water vapor stuck between molecules in the air. The air’s ability to hold water depends on the air temp The hotter the air, the more water the air can hold Cold air: molecules move slower so droplets of water can start to stick together=condensation Relative humidity: the amount of water vapor(%) compared to the amount the air can hold- tool used is a psychrometer. 100%=air is saturated

12. Relative humidity • If you hear a weather forecaster say that the relative humidity is 50% it means= • The air contains 50% of the water needed for the air to be saturated

13. DEW POINT • The temperature at which air is saturated and condensation forms • Changes with the amount of water vapor in the air • When air near the ground cools to its dew point, water vapor condenses and forms dew

14. APPLYING MATH p457

15. WIND • Why can you fly a kite on some days but not others? • Kites fly because air is moving from regions of high pressure to low pressure • Warm air is less dense and expands causing low atmospheric pressure. • Cool air is more dense and has higher atmospheric pressure

16. Wind Air moving in a specific direction Warm, expanding air has low atmospheric pressure Cool air is dense, sinks and has high atmospheric pressure Wind results because air moves from areas of high to low pressure

17. HOW TO MEASURE WIND DIRECTION AND SPEED • Wind Direction • Wind vane (has an arrow that points in the direction from which the wind is blowing) • Wind sock= has one open end that catches the wind causing the sock to point in the direction from which wind is blowing • Wind speed= measured using an anemometers ( rotating cuffs that spin faster when the wind is strong)

18. REVIEW: What causes winds? • A wind is a horizontal movement of air from a area of high pressure to an area of low pressure • It is this difference in pressure that makes the air move=wind • Winds are measured by direction and speed • The anemometer is the tool we use to measure this • Wind chill=↑ cooling the wind causes

19. Review ch. 15 Local Winds • The land cools and heats faster than the ocean. Water holds heat longer than land, and takes longer to heat or cool. SEA BREEZE During the day, the land gets hotter faster than the water. The heated air rises, leaving behind an area of low pressure. Wind from the cooler sea blows in to take the place of that warmer air. These happen during the day!

20. Review ch 15LandBreezes At night the lands cools off faster than the sea. Cool air sinks creating an area of high pressure. Wind blows from the land to the sea.

21. Cloud Formation • Form when warm air is forced upward, expands and cools • Clouds form when water vapor condenses on particles (dust, salt, etc) in the air (RELATIVE HUMIDITY IS 100%) • The temperature in which condensation begins is called the dew point

22. Cloud Formation

23. Clouds Masses of small water droplets or tiny ice crystals that float in the air. Why don’t clouds fall?? Clouds are classified by their shapeand height (vary with temp., pressure, and water vapor in the atmosphere

24. SHAPE OF CLOUDS • 3main types are cirrus, cumulus, and stratus. • LATIN ROOTS - Ciruscomes from the word meaning “lock of hair” - Cumulus come from the word meaning “heap” • Stratus comes from the word meaning layer • Nimbus come from the word meaning “rain bearing” • Other clouds are a mixture of these three main types.

25. TYPES OF CLOUDS • Cirrus Clouds: wispy, feathery clouds • Cirro- means “curled” or “feathery” -comes from a word meaning “lock of hair” **Form only at high levels, therefore are made of ice crystals -Usually signal of a clear day

26. Types of Clouds • Cumulus Clouds: are puffy white cotton ball looking clouds • Cumulo- means “heaped” or “piled” • ***Usually signal good weather, but if the atmosphere is unstable, can build into towering clouds that produce showers and thunderstorms.

27. Cumulonimbus Clouds • These are thunderstorm clouds • NIMBUS= rain

28. Stratus Clouds • Stratus Clouds: clouds that form in flat layers- cover all or most of the sky and are low level clouds • When air is cooled to its dew point near the ground it forms a status cloud called FOG

29. Clouds classified by height= • Cirro- high clouds • Alto=middle elevation clouds • Strato= low elevation • Ex. Cirrostratus-> made of ice crystals and form high in the Earths atmosphere • Ex. Altostratus-> form in middle layers

30. Rain or Snow?? • - Clouds associated with rain or snow usually have the word “nimbus” (Latin for dark rain cloud) attached to them • CUMULONIMBUS-when a cumulus cloud grows into a thunder storm • Nimbostratus-layered clouds that can bring long, steady rain or snow

31. Other Cloud Types Cirrocumulus Cirrostratus Stratocumulus Cumulonimbus

32. More Cloud Types Altostratus Altocumulus Nimbostratus

33. Precipitation • Water that falls from the clouds • Air temperature determines the form of precipitation that falls • 4 main types of Precipitation: • Rain, Sleet, Snow and Hail= -precipitation in the form of lumps of ice -HAIL forms in cumulonimbus clouds of thunderstorms when water freezes

34. Types ofPrecipitation Rain Sleet Snow Hail

35. WEATHER PATTERNSSECTION 2 • AIM: How is weather associated with fronts and low and high pressure? • DO NOW: How can we use clouds as an indicator of severe weather • Homework: Page 463 Reading check -Page 464 Figure 11 , DESCRIBE: What type of weather occurs at front boundaries -Page 465 Figure 12- IDENTIFY some things that tall cumulonimbus clouds produce

36. Air Masses • A large body of air that has properties similar to the part of the Earth’s surface over which it develops.

37. Air Masses • Example: an air mass that develops over land is dry compared to one that develops over water • If developed in the tropics it is warmer than that which developed over colder regions

39. Air Mass Map

40. HIGHS AND LOWS • Pressure Systems -descending (going down)=H pressure -ascending (going up)=L pressure

42. Weather Foldable • Warm front • Cold front • Occluded front • Stationary Front

43. Fronts: the boundary between 2 air masses This is the symbol on a map for a warm front • Warm Front: warm air slides over departing cold air- large bands of precipitation form

44. This is the symbol for a cold front Cold Fronts • Cold air pushes under a warm air mass. Warm air rises quickly=narrow bands of violent storms form

45. This is the weather map symbol for an occluded front Occluded Front • 2 air masses merge and force warm air between them to rise quickly. Strong winds and heavy precipitation will occur

46. This is the weather map symbol for a stationary front Stationary Front • Warm or cold front stops moving. Light wind and precipitation may occur across the front boundary

47. Reading a weather map • ISOBAR= connects areas of equal pressure BAR comes from BARometric pressure

48. Reading a weather map... • Isotherm: Connects areas of equal temperature; therm means temperature

49. Weather Station (not on the TV)