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 10

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 16

17. HOW TO MEASURE WIND DIRECTION AND SPEED
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. SEA BREEZE 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 15Land Breezes
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 22

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 shape and height (vary with temp., pressure, and water vapor in the atmosphere 23

24. SHAPE OF CLOUDS 3 main types are cirrus, cumulus, and stratus.
LATIN ROOTS
- Cirus comes 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 of Precipitation
Rain
Sleet
Snow
Hail

35. WEATHER PATTERNS SECTION 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
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
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)