Unit 4 - Weather, Unit 4 - Weather, Climate, and BiomesClimate, and Biomes

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What is Weather?What is Weather?

Definition:Definition:

- the state or condition of the - the state or condition of the variables of the atmosphere at any variables of the atmosphere at any given location for a given location for a shortshort period of period of timetime

- in fact, - in fact, meteorologymeteorology is the study is the study of the weatherof the weather

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Where does Weather Where does Weather Occur?Occur?

Remember: Weather occurs Remember: Weather occurs in the layer of the atmosphere in the layer of the atmosphere called the TROPOSHERE!!!called the TROPOSHERE!!!

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How do we Measure the How do we Measure the Weather Variables?Weather Variables?

Air Pressure: Air Pressure:

Caused by the weight of the Caused by the weight of the atmosphere, so air pressure is the atmosphere, so air pressure is the greatest at Earth’s surface and greatest at Earth’s surface and decreases as you go higher in the decreases as you go higher in the atmosphere (think of diving deep in the atmosphere (think of diving deep in the ocean).ocean).

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How do we Measure the How do we Measure the Weather Variables?Weather Variables?

- Measuring air Measuring air pressure:pressure:

- Measured using a Measured using a barometerbarometer

- Barometers Barometers measure the measure the effect of weight effect of weight from the from the atmosphereatmosphere

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2 Factors that Affect 2 Factors that Affect Air PressureAir Pressure

1. Temperature: Measured with a 1. Temperature: Measured with a thermometer in degrees thermometer in degrees

Celsius.Celsius.

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Weather Shelter – where official temperature readings are taken

Factors that Affect Air Factors that Affect Air PressurePressure

Temperature continued:Temperature continued:

Cool air is more dense than warm Cool air is more dense than warm air.air.If air is warmed, it becomes less If air is warmed, it becomes less

dense and air pressure decreasesdense and air pressure decreasesIf air is cooled, it becomes more If air is cooled, it becomes more

dense and air pressure increases.dense and air pressure increases.

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2 Factors that Affect 2 Factors that Affect Air PressureAir Pressure

2.2. Altitude: Altitude: Air pressure decreases as you go up Air pressure decreases as you go up

(when altitude increases).(when altitude increases). This is due to the fact that there is This is due to the fact that there is

less of the atmosphere above you less of the atmosphere above you pushing down.pushing down.

This is why people who climb tall This is why people who climb tall mountains carry oxygen tanks mountains carry oxygen tanks with them.with them.

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How Air Pressure How Air Pressure Affects a Rising BalloonAffects a Rising Balloon

http://www.classzone.com/books/earth_science/terc/content/visualizations/es1901/es1901page01.cfm?chapter_no=visualization

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Warm air is rising – less dense

Cool air is sinking – more dense

Cool air takes the place of the rising warm air-to fill space

As the warm air rises, it becomes cooler and more dense

What is Wind?What is Wind?

WINDWIND – –

horizontal movement of air parallel to horizontal movement of air parallel to Earth’s surfaceEarth’s surface

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What Causes the Wind?What Causes the Wind?

wind is created by the uneven wind is created by the uneven heating of Earth’s surfaceheating of Earth’s surface

uneven heating causes uneven heating causes differences in air pressuredifferences in air pressure

wind will always blow from areas wind will always blow from areas of high pressure to areas of lower of high pressure to areas of lower pressurepressure

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Measuring the WindMeasuring the Wind

Wind Measurement requires a size and direction Wind Measurement requires a size and direction to describe itto describe it

Ex. 70 mi/hr SE windEx. 70 mi/hr SE wind

- wind is named for the direction from which it - wind is named for the direction from which it came fromcame from

Ex. A south wind (heading north but Ex. A south wind (heading north but came from the south)came from the south)

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Measuring the WindMeasuring the WindWind continued…Wind continued…

The speed of wind is measured using an The speed of wind is measured using an anemometeranemometer

- measured in mi/hr or knots - measured in mi/hr or knots (boats)(boats)

The direction of the wind is The direction of the wind is

determined using a determined using a weather vaneweather vane14

Wind FactsWind FactsWind continued…Wind continued…

Wind is responsible for creating waves Wind is responsible for creating waves in the ocean because energy from the in the ocean because energy from the wind is transferred to the waterwind is transferred to the water

Jet streams Jet streams - areas of very fast winds in - areas of very fast winds in the upper atmosphere that separates the upper atmosphere that separates warm air masses from cool air masses.warm air masses from cool air masses.

Affects where weather and storms flow.Affects where weather and storms flow.

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Wind Facts:Wind Facts:JetstreamJetstream

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Jet stream FactsJet stream Facts

During World War II the Japanese used the air During World War II the Japanese used the air stream to fly balloons at 30,000 feet across stream to fly balloons at 30,000 feet across the Pacific to the USA.the Pacific to the USA.

The jet stream is the reason why transatlantic The jet stream is the reason why transatlantic flights are quicker going from America to flights are quicker going from America to Europe.Europe.

They can be as fast as 315mph.They can be as fast as 315mph.17

Factors of WeatherFactors of Weather

CLOUDSCLOUDS

Masses of water vapor combined Masses of water vapor combined with dust particles in the with dust particles in the atmosphereatmosphere

Takes about 1 million cloud Takes about 1 million cloud droplets to make a single raindropdroplets to make a single raindrop

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Water CycleWater Cycle

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How do Clouds Form?How do Clouds Form?

1.1. Water Water evaporatesevaporates from the surface of Earth from the surface of Earth into the atmosphere (liquid changes to a gas).into the atmosphere (liquid changes to a gas).

1.1. Water vapor molecules Water vapor molecules condensecondense on dust on dust particles (gas changes to a liquid).particles (gas changes to a liquid).

1.1. When droplets become heavy enough, the When droplets become heavy enough, the water falls toward Earth as water falls toward Earth as precipitationprecipitation..

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4 Basic Cloud Types4 Basic Cloud Types

1)1) CumulusCumulus - Look like a - Look like a heap of cotton balls or heap of cotton balls or whipped cream; whipped cream; summertime; typically summertime; typically no precipitationno precipitation

1)1) StratusStratus - Clouds that - Clouds that look like a flat blanket in look like a flat blanket in the sky; low rain clouds; the sky; low rain clouds; cover whole skycover whole sky

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4 Basic Cloud Types4 Basic Cloud Types

3) 3) CirrusCirrus - Look like curls of - Look like curls of white hair; fair-weather white hair; fair-weather cloud; whispy; look like cloud; whispy; look like airplane tracksairplane tracks

4) 4) Cumulonimbus Cumulonimbus - cotton-like - cotton-like clouds that have built up in clouds that have built up in the middle or high part of the middle or high part of the atmosphere; tall, deep, the atmosphere; tall, deep, & dark; bring lightening, & dark; bring lightening, heavy rain, and severe heavy rain, and severe weatherweather

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Name that CloudName that Cloud

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Stratus Cirrus Cumulonimbus Cumulus

PrecipitationPrecipitation

PRECIPITATIONPRECIPITATION- -

falling of liquid or solid water from falling of liquid or solid water from clouds toward the surface of Earthclouds toward the surface of Earth

to occur, ice crystals or water droplets to occur, ice crystals or water droplets in clouds must come together to in clouds must come together to become big enough so that they will become big enough so that they will fall under the influence of gravityfall under the influence of gravity

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PrecipitationPrecipitation

Forms of precipitation include:Forms of precipitation include:

rainrain drizzledrizzle

snowsnow sleetsleet

hailhail freezing rainfreezing rain

- - rain gaugerain gauge: used to measure liquid : used to measure liquid precipitation; measured in inches or cmprecipitation; measured in inches or cm

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Identify the Form of Identify the Form of PrecipitationPrecipitation

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PrecipitationPrecipitation

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Severe WeatherSevere Weather

ThunderstormsThunderstorms

Heavy rain & electricity (lightening) form Heavy rain & electricity (lightening) form from cumulonimbus cloudsfrom cumulonimbus clouds

Lightening is electricity that results from Lightening is electricity that results from charges when water vapor molecules charges when water vapor molecules collide with each othercollide with each other

Lightening bolts are hot! (30,000-50,000°F)Lightening bolts are hot! (30,000-50,000°F)

This heats air around it so fast that the air This heats air around it so fast that the air expands sending out vibrations & shock expands sending out vibrations & shock waves we hear as sound (thunder)waves we hear as sound (thunder)

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Thunderstorms Thunderstorms continuedcontinued

At any time, over At any time, over 2,000 thunderstorms 2,000 thunderstorms are happening on are happening on EarthEarth

Hail can come from T Hail can come from T storms where water storms where water encounters below encounters below freezing tempsfreezing temps

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Severe WeatherSevere Weather

TornadosTornados

Rapidly rotating extremely low Rapidly rotating extremely low pressure funnel that hangs down from pressure funnel that hangs down from thunderstorm clouds towards Earth’s thunderstorm clouds towards Earth’s surfacesurface

True tornados touch Earth’s surfaceTrue tornados touch Earth’s surface

Narrow & at least 100 ft. wideNarrow & at least 100 ft. wide

Can reach wind speeds of 350 mphCan reach wind speeds of 350 mph30

Tornados continuedTornados continued Not clear how Not clear how

tornados are formed tornados are formed except formed when except formed when 2 air masses with 2 air masses with huge temperature huge temperature differences from differences from thunderstorm clouds thunderstorm clouds collidecollide

Low air pressure Low air pressure vacuums upvacuums up

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Measuring Tornado Measuring Tornado StrengthStrength

Measured using the Fujita Measured using the Fujita Scale.Scale.

From F0-F2 is moderate to From F0-F2 is moderate to significant – winds are 40-significant – winds are 40-157 mph. Can tear off roofs 157 mph. Can tear off roofs of houses.of houses.

From F3-F4 is a From F3-F4 is a devastating tornado devastating tornado 158 to 260 mph and 158 to 260 mph and can level houses and can level houses and throw cars. throw cars.

F5 is an incredible F5 is an incredible tornado 261-318 tornado 261-318 mph. Houses lifted mph. Houses lifted off foundations, bark off foundations, bark pulled off trees.pulled off trees.

F6 is inconceivable – F6 is inconceivable – never been achievednever been achieved

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Tornado VideosTornado Videoshttp://video.national

geographic.com/video/player/environment/environment-natural-disasters/tornadoes/tornado-montage.html

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Severe Weather-Severe Weather-HurricanesHurricanes

HurricanesHurricanes

Large rotating, low-Large rotating, low-pressure stormspressure storms

Develop late in Develop late in summer, early fall in summer, early fall in Atlantic Ocean Atlantic Ocean between South between South America and Africa America and Africa (where waters are (where waters are very warm)very warm)

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Severe Weather-Severe Weather-HurricanesHurricanes

Evaporation of warm waterEvaporation of warm water

Condensation – releases energy Condensation – releases energy for the stormfor the storm

All low pressure systems rotate All low pressure systems rotate counterclockwise. (in the northern counterclockwise. (in the northern hemisphere)hemisphere)

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Severe Weather-Severe Weather-HurricaneHurricane

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Rating Hurricane Rating Hurricane StrengthsStrengths

http://www.nhc.noaa.gov/aboutsshs.shtml

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Other Forms of Severe Other Forms of Severe WeatherWeather

TsunamiTsunami Series of water waves Series of water waves

caused by large body caused by large body of water (ocean) that of water (ocean) that is rapidly displacedis rapidly displaced

Means harbor wave Means harbor wave (in Japanese)(in Japanese)

Caused by: Caused by: earthquakes, volcano earthquakes, volcano eruptions, eruptions, underwater underwater explosions (nuclear explosions (nuclear devices), etc.devices), etc.

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ClimatesClimates

Define Climate:Define Climate:

- - long term weather pattern of an area long term weather pattern of an area including precipitation, temp, and windincluding precipitation, temp, and wind

- causes are solar radiation to an area- causes are solar radiation to an area

- recall, the Earth has seasons because - recall, the Earth has seasons because of the 23 ½ ° tilt which means the of the 23 ½ ° tilt which means the amount of solar radiation to hit the amount of solar radiation to hit the Earth varies depending upon the Earth varies depending upon the Earth’s location to the SunEarth’s location to the Sun

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Types of ClimateTypes of Climate

1.1. Tropical climateTropical climate - constant high - constant high temps and raintemps and rain

2.2. Dry climatesDry climates - 30% of Earth’s land - 30% of Earth’s land area; hot temps, low precipitation, area; hot temps, low precipitation, vegetation scarce; high solar vegetation scarce; high solar radiation, few cloudsradiation, few clouds

3.3. Mild climatesMild climates - warm, muggy weather - warm, muggy weather in summer and cool weather in winterin summer and cool weather in winter

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Types of ClimateTypes of Climate

4. 4. Continental climatesContinental climates - area where - area where tropical & polar air masses collide; tropical & polar air masses collide; rapid & violent changes in weather; rapid & violent changes in weather; summer & winter temps are extremesummer & winter temps are extreme

5. 5. Polar climatesPolar climates - coldest regions on - coldest regions on Earth; constant cold; precipitation is Earth; constant cold; precipitation is low; cold air cannot hold as much low; cold air cannot hold as much moisturemoisture

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In these climates, there exist systems of animals and vegetation that thrive in that temperature range

called BIOMES

BiomesBiomes

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List of World BiomesList of World Biomes

Biome Picture

1. Tropical Rainforest

2. Tropical Dry Forest

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List of World BiomesList of World Biomes

Biome Picture

3. Tropical Savannah

4. Desert

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List of World BiomesList of World Biomes

Biome Picture

5. Temperate Grasslands

6. Temperate Forests

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List of World BiomesList of World Biomes

Biome Picture

7. Northwestern Coniferous Forest

8. Taiga (Boreal Forest)

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List of World BiomesList of World Biomes

Biome Picture

9. Tundra

10. Estuary

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List of World BiomesList of World Biomes

Biome Picture

11. Saltwater

12. Freshwater

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