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?

Weather Temporary behavior of

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

Small geographic area

Can change rapidly

Weather--The study of weather is meteorology

--Someone who studies weather is called a meteorologist

Climate Long-term behavior of

atmosphere (100+ years) LargeLarge geographic area Very slowslow to change

POLAR90o -60o latitudeCool summers, cold year-

roundDry

TEMPERATE60o-30o latitudeTrue SeasonsVariety of climate patternsModerate precipitation

(rain/snow)

TROPICAL30o - equatorNo winter, warm year-roundHigh 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?

1.1. The The SunSun

2.2. The WaterThe Water Cycle Cycle

3.3. The AtmosphereThe Atmosphere

4.4. The The OceanOcean

How Does the Sun Affect Weather?It warms the atmosphere & oceansIt creates climate zonesIt keeps the water cycle goingIt affects weather patterns

The Water Cycle

All the water on the planet is recycled in this manner!

Parts of the Cycle

EvaporationEvaporation—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!

transpiration

Parts of the CycleCondensationCondensation—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.

PrecipitationPrecipitation

Liquid water = rain

Frozen water = snow or sleet or hail

Rain Clip

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 How does the atmosphere affect atmosphere affect weather?weather?

The atmosphere is a mixture of gases that surrounds the EarthHas five different layers; each has different properties

We’ll label them in just a minute…

Air Temperature and Pressure change with altitudeWeather occurs in the layer closest to Earth (troposphere)

TroposphereStratosphere

Mesosphere

Ionosphere

Exosphere

Thermosphere

Write in the Write in the labels!labels!

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 MassesAir Masses

= body of air with a certain temperature and moisture levelCan be warm or coldCan contain a lot of moisture or not a lot of moisture

FrontsFronts = places where air masses meet4 Types: Warm, Cold, Occluded, StationaryEach kind can bring different kinds of weather

Occluded Front: Stationary Front:

Science Saurus 221/222 & Reading a Weather

Map Worksheet

How does Air How does Air Pressure affect Pressure affect weather?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 comingRising Air Pressure = fair weather comingSteady Air Pressure = no change is coming

Pressure Systems

WindsWinds = created from differences in air pressure

Moves from areas of HIGH to LOW pressureGreater the difference in pressure, the FASTER the wind blowsMeasured with wind vanes and anemometers or you can estimate with the Beaufort Wind ScaleScienceSaurus 224/225

Beaufort Wind Scale

Global WindsThousands of kilometers long; can cause weather to move in different directions

Jet stream, prevailing westerlies, doldrums, horse latitudes, trade windsBig Winds Blowin’ Worksheet & Big Winds Blowin’ Worksheet &

Science Saurus Section 217Science Saurus Section 217

Global WindsCaused by the temperature difference in different regions

Hot Tropical Regions—causes air to rise

Cold polar Regions—causes air to sink

Global WindsAlso 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’ WorksheetBig 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

moisturemoisture in the air compared to what the air could hold

How “full” of water the air is Expressed as % 100% relative humidity =

saturatedsaturated air

Relative Humidity Test Applethttp://itg1.meteor.wisc.edu/wxwise/relhum/rhac.html

Relative HumidityControlled by temperatureControlled by temperature

1. WarmWarm air holds more moisture than cool air (more space for water vapor between air molecules)2. As air warmswarms, relative humidity decreasesdecreases3. As air coolscools, relative humidity increasesincreases

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 1. If dew point temp. is above freezing:freezing:

a. water vapor condenses as liquidliquidb. dew will form on surfaces

Dew Point

c. cloud droplets will form in air

2. If dew point temp. is below 2. If dew point temp. is below freezing:freezing:a. water vapor condenses as a solidb. frost on surfacesc. 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 evaporate into the atmosphere?

RRaaiinnbboowwss

Caused by sunshinesunshine 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 behindbehind you and raindrops in the air

Diagram:

Rainbow by Brainpop

How does the Ocean How does the Ocean affect weather?affect weather?

Ocean currents affect the temperature of the land they pass byCold ocean currents = cooling effectWarm ocean currents = warming effectTemperature changes affect pressure – which then creates WINDSWinds blow this cooling or warming effect over the land

http://earth.rice.edu/MTPE/hydro/hydrosphere/topics/Ocean_Atm_Circ_ElNino.mov

http://www.wunderground.com/MAR/

Science Saurus Sections 203-204-205-206Science Saurus Sections 203-204-205-206

Advanced Weather by Brainpop

Violent Weather

ThunderstormsRequires a mature cumulonimbus

cloud

Signs

a. Sudden reversal of wind directionb. Noticeable increase in wind speedc. Sudden drop in temperature

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

Thunderstorm by Brainpop

Thunderstorms

Safety Rules Stay indoors Prepare for lightning, strong

winds Listen on radio/TV for tornado

watch/warning Thunderstorms don’t last long

Lightning Lightning StormStorm Cumulonimbus cloud becomes

electrically charged and ground below has opposite charge

Lightning stroke: flow of currentcurrent thru air (a poor conductor) from the – to the +Lightning can flow from cloud to ground, cloud to cloudcloud, and from ground to cloudBright light is caused by glowingglowing air molecules heated by the currentLightning follows the path of least resistanceresistance (easiest way to positive)Lightning rod offers lightning an easyeasy, safe path to the ground (+)

ThunderThunder is the shock wave caused by the explosive expansion of heated air

Sound travels @ about 11001100 ft/sec in air

5,280 ft in one mileDistance from you to lightning =

number of secondsseconds between seeing the flash and hearing the thunder divided by 5.

(5,280 ft / 1100 ft/sec = 5 seconds)

Types of LightningStreak or bolt

a. Single or branched lines of lightb. Common in Puget Sound area

SheetSheeta. shapeless flash over wide area

b. is cloud-to-cloud bolt hidden by the cloudsc. common in Puget Sound area

Other types of lightningOther types of lightning

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

Safety rules for lightning storms 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 Avoid hilltops If your hair stands on end, or your skin

tingles, drop to the ground but try to keep as little contact with the ground as possible

Lightning Strikes

(17 minutes)

Stories of people hit by lightning

TornadoTornado (a.k.a twister, cyclone) 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

called “waterspouts”

Behavior of a tornado is unpredictable

Typical tornado will:1. Occur between 3-7 pm2. Travel 4 miles3. Be 300-400 m wide4. Travel 25-40 mi/hour5. Have wind speeds up to 300 mi/hr6. Produce extremely low pressure7. Be dark due to debris picked up

Tornado by Brainpop

Safety Rules 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 homea. open windows, doorsb. seek shelter in basement or under heavy table in middle of house

On the trail of a tornado

Tropical CycloneTropical CycloneNicknamesNicknames

1. Atlantic: hurricane2. SE Asia, Japan: typhoon3. Australia: willy-willy4. Indian Ocean: cyclone

Tropical CycloneTropical CycloneRated by wind speed (category 1 to 5)Starts and grows over warm ocean waterComposed of bands of thunderstorms spiraling counterclockwise around a low pressure center

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

a. Small region of low pressureb. Surrounded by highest windsc. Calm, peaceful, sunny weatherd. Last for about 1 hour as hurricane

passes by

Hurricances by Brainpop

Safety Rules Prepare for high winds Prepare for flooding (greatest

source of damage)a. Up to 20 in. of rainb. Flooding by coastal water

3. Prepare for thunderstorms 4. Have on hand stored food,

water, blankets, candles, matches, radio, etc.

5. Seek shelter Hurricanes Clip