WeatherWeather

Learning Goal: Learning Goal:

Comprehend and apply Comprehend and apply weather in role play of being weather in role play of being

meteorologists. meteorologists.

El NinoEl Nino

• El Nino - (El Nee-nyo) is the warming El Nino - (El Nee-nyo) is the warming of water in the Pacific Ocean.of water in the Pacific Ocean.

• Rain and flooding along the Pacific CoastRain and flooding along the Pacific Coast• Warm water disrupts the food chain of Warm water disrupts the food chain of

fish, birds, and sea mammals.fish, birds, and sea mammals.• Tornadoes and thunderstorms in the Tornadoes and thunderstorms in the

southern USsouthern US• Fewer than normal hurricanes in the Fewer than normal hurricanes in the

AtlanticAtlantic

La NinaLa Nina

• La Nina - (Lah Nee-Nyah) is the cooling of La Nina - (Lah Nee-Nyah) is the cooling of water in the Pacific Ocean.water in the Pacific Ocean.

• SnowSnow and rain on the west coast and rain on the west coast • Unusually cold weather in Alaska Unusually cold weather in Alaska • Unusually warm weather in the rest of the USA Unusually warm weather in the rest of the USA • DroughtDrought in the southwest in the southwest • Higher than normal number of Higher than normal number of hurricaneshurricanes in in

the Atlantic the Atlantic

• http://esminfo.prenhall.com/science/geoahttp://esminfo.prenhall.com/science/geoanimations/animations/26_NinoNina.htmlnimations/animations/26_NinoNina.html

Water CycleWater Cycle

• Amount of water Amount of water remains the sameremains the same as it moves through the cycleas it moves through the cycle

• Fresh water is limitedFresh water is limited

• All living organisms need liquid waterAll living organisms need liquid water

• Earth’s water is continually being Earth’s water is continually being recycledrecycled

EvaporationEvaporation – process by which water – process by which water molecules molecules escape into the air by radiant escape into the air by radiant energy from energy from the sun changing water into a the sun changing water into a gas (water gas (water vapor).vapor).

Relative humidityRelative humidity – the percentage of – the percentage of moisture moisture the air holds relative to the the air holds relative to the amount it could amount it could hold at a particular hold at a particular temperature.temperature.

PsychrometerPsychrometer – instrument used to – instrument used to measure the amount of R. humidity in the measure the amount of R. humidity in the air. It consist of two thermometers, one wet air. It consist of two thermometers, one wet and one dry.and one dry.

Cloud formationCloud formation

Clouds form when water vapor in the air Clouds form when water vapor in the air becomes liquid water or ice crystals. becomes liquid water or ice crystals. Water vapor changing into a liquid----Water vapor changing into a liquid----CONDENSATIONCONDENSATION

The temperature at which condensation The temperature at which condensation begins is called begins is called dew pointdew point. .

CumulonimbusCumulonimbus – Thunderstorm clouds – Thunderstorm clouds that produce severe weather, tornadoes, that produce severe weather, tornadoes, hail, strong winds. Have anvil shape to top hail, strong winds. Have anvil shape to top of cloud.of cloud.

CloudsClouds

CumulusCumulus – usually indicate fair weather. 2 – usually indicate fair weather. 2 to 7 miles in the sky (cotton balls).to 7 miles in the sky (cotton balls).

CirrusCirrus – Feathery or fibrous in appearance. – Feathery or fibrous in appearance. Very high altitudes usually between 6 and Very high altitudes usually between 6 and 12 kilometers. Indicate the onset of rain or 12 kilometers. Indicate the onset of rain or snow in a few hours.snow in a few hours.

Stratus cloudsStratus clouds – smooth gray clouds that – smooth gray clouds that cover cover the whole sky and block out the the whole sky and block out the sun are sun are called stratus clouds. These clouds called stratus clouds. These clouds produce steady, light produce steady, light precipitation. precipitation.

PrecipitationPrecipitation – Water vapor that – Water vapor that condenses and forms clouds that can fall to condenses and forms clouds that can fall to the Earth as rain, sleet, snow, freezing rain the Earth as rain, sleet, snow, freezing rain or hail.or hail.

sleetsleet – water droplet that freezes – water droplet that freezes when it when it falls through cold air. (winter)falls through cold air. (winter)

snowsnow – forms when water vapor – forms when water vapor changes changes directly to a solid.directly to a solid.

HailHail – ice balls that fall after water is – ice balls that fall after water is frozen frozen

in the air then pushed further up and in the air then pushed further up and collects collects more water and freezes again, more water and freezes again, over and over and over until it becomes to heavy over until it becomes to heavy to stay to stay suspended in the air. The stronger suspended in the air. The stronger the uplift the uplift the larger the hail stone. the larger the hail stone. (summer)(summer)

Freezing rain – rain that freezes upon Freezing rain – rain that freezes upon contact with the ground.contact with the ground.

IsobarIsobarA line on a weather map connecting A line on a weather map connecting places that have the same air pressureplaces that have the same air pressure

high-pressure systemhigh-pressure system

A generally calm and clear weather A generally calm and clear weather system that occurs when air sinks system that occurs when air sinks down in a high-pressure center and down in a high-pressure center and spreads out toward areas of lower spreads out toward areas of lower pressure as it nears the ground.pressure as it nears the ground.

(More dense cold air)(More dense cold air)

low-pressure systemlow-pressure system

A large and often stormy weather A large and often stormy weather system that occurs when air moves system that occurs when air moves around and into to a low-pressure around and into to a low-pressure center, then moves up to higher center, then moves up to higher altitudes.altitudes.

((Less Dense Warm Air)Less Dense Warm Air)http://www.bom.gov.au/lam/http://www.bom.gov.au/lam/

Students_Teachers/pressure.shtml Students_Teachers/pressure.shtml

StormsStorms

• Caused by:Caused by:• Changes in Changes in temperaturetemperature & drop in & drop in

barometric pressurebarometric pressure• Ex: Hurricanes are a low pressure mass Ex: Hurricanes are a low pressure mass

over tropical (warm) waterover tropical (warm) water• http://news.bbc.co.uk/2/hi/5328524.stm http://news.bbc.co.uk/2/hi/5328524.stm • http://profhorn.meteor.wisc.edu/wxwise/http://profhorn.meteor.wisc.edu/wxwise/

tornado/t.html tornado/t.html • http://www.suu.edu/faculty/colberg/http://www.suu.edu/faculty/colberg/

Hazards/Hurricanes_Noreasters/Hazards/Hurricanes_Noreasters/Hurricanes_Anim_1.html Hurricanes_Anim_1.html

Weather FrontsWeather Fronts

• Air mass-Air mass-a huge body of air that has a huge body of air that has similar temperature, humidity, and similar temperature, humidity, and air pressureair pressure

• FrontFront-the area where two air masses -the area where two air masses meet and do not mixmeet and do not mix

• Dense,cold air moves underneath the Dense,cold air moves underneath the less dense warm air, pushing it up less dense warm air, pushing it up

Front TypesFront Types

• Cold front-Cold front-rapidly moving cold air rapidly moving cold air mass that runs into a slowly moving mass that runs into a slowly moving warm air masswarm air mass

• Move quickly, causing violent stormsMove quickly, causing violent storms

• Warm front- Warm front- warm air that collides warm air that collides with cold air with cold air

• Moves slowly, causing fog or rain for Moves slowly, causing fog or rain for days, and in the winter, snowdays, and in the winter, snow

Cold FrontCold Front((More Dense cold Air)More Dense cold Air)

Cold Front

Warm FrontWarm Front(Less Dense Warm Air)(Less Dense Warm Air)Warm Front

Stationary FrontStationary Front

• http://www.stevemcentee.com/http://www.stevemcentee.com/animation3.html animation3.html

Stationary Front

Weather ForecastingWeather Forecasting

• MeteorologistsMeteorologists-scientists who study -scientists who study weather and try to predict itweather and try to predict it

• Forecasting has greatly improved Forecasting has greatly improved due to computer technologydue to computer technology

• Collecting weather data has Collecting weather data has improved because of satellites and improved because of satellites and balloonsballoons

Seasons and ClimateSeasons and Climate

• Earth has seasons because Earth’s Earth has seasons because Earth’s axis tilted as it moves around the sunaxis tilted as it moves around the sun

• WinterWinter-axis tilted away from sun -axis tilted away from sun resulting in shorter days and indirect resulting in shorter days and indirect raysrays

• SummerSummer-axis tilted toward sun -axis tilted toward sun resulting in longer days and direct resulting in longer days and direct raysrays

ClimateClimate

• Caused byCaused by::• AltitudeAltitude• LatitudeLatitude• Mountain barriersMountain barriers• Proximity (closeness) to oceansProximity (closeness) to oceans

• Climate is classified by Climate is classified by precipitationprecipitation and and temperaturetemperature based on these factors based on these factors

• http://www.edheads.org/activities/http://www.edheads.org/activities/weather/index.shtml weather/index.shtml