Weather and Climate - PowerPoint

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					Intro to Weather Clip

Weather by Brainpop
1) What cycle is the basis of our weather? 2) What causes precipitation to occur? 3) Where do storms usually occur?


Temporary behavior of atmosphere (what’s going on at any certain time)


Small geographic area Can change rapidly


--The study of weather is meteorology

--Someone who studies weather is called a meteorologist

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Long-term behavior of atmosphere (100+ years) Large geographic area Very slow to change

90o -60o latitude Cool summers, cold yearround Dry

60o-30o latitude True Seasons Variety of climate patterns Moderate precipitation (rain/snow)

30o - equator No winter, warm year-round High temp, rainfall, humidity

Climate Types by Brainpop
1.What is climate? 2.Where are tropical climates most likely to be? 3.What does “arid” mean?

What Factors Affect Weather & Climate?
Sun 2. The Water Cycle 3. The Atmosphere 4. The Ocean
1. The

How Does the Sun Affect Weather?
It warms the atmosphere & oceans It creates climate zones It keeps the water cycle going It affects weather

The Water Cycle
All the water on the planet is recycled in this manner!

Parts of the Cycle
Evaporation—Water going from a liquid to a gas (gains energy from the sun)

Parts of the Cycle
*Transpiration—evaporation of water from/out of plants. Locate this on the diagram!


Parts of the Cycle
Condensation—Water going from a gas to a liquid (cools or loses energy)  When this happens in the atmosphere, CLOUDS form.

Clouds by Brainpop

Parts of the Cycle
Precipitation—when water falls out the atmosphere. Forms when the water droplets in clouds become too heavy to stay up.


Liquid water = rain
Rain Clip


Frozen water = snow or sleet or hail

The Water Cycle

Water Cycle by Brainpop

Water Cycle Advanced by Brainpop

The Water Cycle by Brainpop
1) What process must happen for clouds to form?
2) What is “collection”?

3) Name one way to conserve water.

How does the atmosphere affect weather?
The atmosphere is a mixture of gases that surrounds the Earth Has five different layers; each has different properties
We’ll label them in just a minute„

Air Temperature and Pressure change with altitude

Write in the labels!



Mesosphere Stratosphere Troposphere

Ozone layer

Earth’s Atmsophere by Brainpop

1. What is ozone? 2. What layer of the atmosphere does weather occur in? 3. What 2 gases compose the most of Earth’s Atmosphere?

Air Masses

= body of air with a certain temperature and moisture level Can be warm or cold Can contain a lot of moisture or not a lot

= places where air masses meet 4 Types: Warm, Cold, Occluded, Stationary Each kind can

Occluded Front:

Stationary Front:

Science Saurus 221/222 & Reading a Weather Map Worksheet

How does Air Pressure affect weather?
How much the earth’s atmosphere is pressing down on us

Measured with a BAROMETER If it CHANGES, then new weather is on the way:
Falling Air Pressure = stormy weather coming Rising Air Pressure = fair weather

Pressure Systems

Winds = created from differences in air pressure
Moves from areas of HIGH to LOW pressure Greater the difference in pressure, the FASTER the wind blows Measured with wind vanes and anemometers or you can estimate with the Beaufort Wind Scale
ScienceSaurus 224/225

Beaufort Wind Scale

Global Winds
Thousands of kilometers long; can cause weather to move in different directions Jet stream, prevailing westerlies, doldrums, horse latitudes, trade winds Worksheet & Big Winds Blowin’
Science Saurus Section 217

Global Winds
Caused by the temperature difference in different regions
Hot Tropical Regions—causes air to rise  Cold polar Regions—causes air to sink

Global Winds
Also affected by Earth’s Spin


Coriolis Effect = causes winds to curve to the right in the N. Hemisphere; to the left in the S. Hemisphere

Big Winds Blowin’ Worksheet

Winds by Brainpop
1. What does warm air do?

2. What do you call winds that blow all the time in the same part of the world? 3. What are jet streams?

Relative Humidity
Measure of the amount of moisture in the air compared to what the air could hold  How “full” of water the air is  Expressed as %  100% relative humidity = Relative Humidity Test Applet saturated air

Relative Humidity
Controlled by temperature 1. Warm air holds more moisture than cool air (more space for water vapor between air molecules) 2. As air warms, relative humidity

3. As air cools, relative humidity


Dew Point

=Temperature at which the air is saturated (100% relative humidity)

Several events can occur when the dew point temp. is reached: 1. If dew point temp. is above freezing:
a. water vapor condenses as liquid b. dew will form on surfaces

Dew Point
c. cloud droplets will form in air

2. If dew point temp. is below freezing: a. water vapor condenses as a solid b. frost on surfaces c. snow (or hail) in the air

Humidity by Brainpop
1. What single factor controls humidity? 2. What temperature air can hold the most water molecules? 3. What causes water to





Caused by sunshine on raindrops White light (all colors) is refracted (bent) into colors as it enters and exits the drop To see a rainbow you must have the sun behind you and raindrops in the air Diagram:

Rainbow by Brainpop

How does the Ocean affect weather?
Ocean currents affect the temperature of the land they pass by Cold ocean currents = cooling effect Warm ocean currents = warming effect Temperature changes affect pressure – which then creates WINDS Winds blow this cooling or warming effect over the land

Science Saurus Sections 203-204-205-206

Advanced Weather by Brainpop

Violent Weather

Requires a mature cumulonimbus cloud


Sudden reversal of wind direction Noticeable increase in wind speed

Possible weather:
a. b. c. d. e. f. heavy rains (flash floods) lightning (forest fires) thunder (frightens animals) hail (crop damage) tornadoes strong, gusty winds

Thunderstorm by Brainpop

Safety Rules
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Stay indoors Prepare for lightning, strong winds Listen on radio/TV for tornado watch/warning Thunderstorms don’t last long

Lightning Storm
Cumulonimbus cloud becomes electrically charged and ground below has opposite charge

Lightning stroke: flow of current thru air (a poor conductor) from the – to the + Lightning can flow from cloud to ground, cloud to cloud, and from ground to cloud Bright light is caused by glowing air molecules heated by the current Lightning follows the path of least resistance (easiest way to positive) Lightning rod offers lightning an

Thunder is the shock wave caused by the explosive expansion of heated air Sound travels @ about 1100 ft/sec in air 5,280 ft in one mile Distance from you to lightning = number of seconds between seeing the flash and hearing the thunder

Types of Lightning
Streak or bolt
a. b.

Single or branched lines of light Common in Puget Sound area

a. shapeless flash over wide area b. is cloud-to-cloud bolt hidden by the clouds c. common in Puget Sound area

Other types of lightning
a. heat, ribbon, beaded (types of bolt) b. ball (only other shape lightning can have)

Safety rules for lightning storms


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Stay indoors Stay away from anything that conducts electricity (stove, sink, telephone, TV) Get out of the water and off of small boats Stay away from open doors, windows, fireplaces Stay in your car (very safe place to be) Don’t stand under lone trees or in open places

Lightning Strikes
(17 minutes)

Stories of people hit by lightning


(a.k.a twister,

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Counterclockwise column of rotating air extending from cumulonimbus cloud Per square foot, is the most destructive atmospheric event Rated by wind speed (F1 to F5) “Tornado season” = April, May, June Tornadoes that form over water are

Behavior of a tornado is unpredictable Typical tornado will: 1. Occur between 3-7 pm 2. Travel 4 miles 3. Be 300-400 m wide 4. Travel 25-40 mi/hour 5. Have wind speeds up to 300 mi/hr 6. Produce extremely low pressure 7. Be dark due to debris picked up

Tornado by Brainpop

Safety Rules
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Rule #1: Take immediate action! Move away from tornado’s path

Tornado’s path

Move away at a right angle

Lie flat in nearest ditch, etc. At home a. open windows, doors b. seek shelter in basement or under heavy table in middle of house
On the trail of a tornado

Tropical Cyclone
Nicknames 1. Atlantic: hurricane 2. SE Asia, Japan: typhoon 3. Australia: willy-willy 4. Indian Ocean: cyclone

Tropical Cyclone
Rated by wind speed (category 1 to 5) Starts and grows over warm ocean water Composed of bands of thunderstorms spiraling counterclockwise around a low pressure center

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Several hundred miles wide Last many days (even weeks) Winds from 74-200 mi/hr Contains an “eye” Hurricances
a. b. c.



Small region of low pressure Surrounded by highest winds Calm, peaceful, sunny weather Last for about 1 hour as hurricane passes by


Safety Rules
 

Prepare for high winds Prepare for flooding (greatest source of damage)
a. b.

Up to 20 in. of rain Flooding by coastal water

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3. Prepare for thunderstorms 4. Have on hand stored food, water, blankets, candles, matches, radio, etc. Hurricanes Clip 5. Seek shelter

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