1 weather and climate content goal 3: the learner will conduct investigations and use appropriate...

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Weather and Climate Weather and Climate ContentContent

Goal 3:Goal 3: The learner will conduct The learner will conduct investigations and use appropriate investigations and use appropriate

technology to build an technology to build an understanding of weather and understanding of weather and

climate.climate.

Alex RichardsonAlex RichardsonElementary Science CoachElementary Science [email protected]@wsfcs.k12.nc.us

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Background ConceptsBackground Concepts

Three big factors influence weather and Three big factors influence weather and climate worldwide: the Sun, the water cycle, climate worldwide: the Sun, the water cycle, and the atmosphere.and the atmosphere.

The Sun is perhaps the largest influence on The Sun is perhaps the largest influence on our planet’s weather and climate.our planet’s weather and climate.

Climate is determined by the amount of Climate is determined by the amount of sunlight a location receives.sunlight a location receives.

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Changes in the Sun’s Changes in the Sun’s intensity through time intensity through time as well as changes in as well as changes in the amount of sunlight the amount of sunlight let into the Earth let into the Earth system can drastically system can drastically affect our world. affect our world.

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The Earth is surrounded by five The Earth is surrounded by five layers of the atmosphere.layers of the atmosphere.

ExosphereExosphere

ThermosphereThermosphere

MesosphereMesosphere

StratosphereStratosphere

TroposphereTroposphere

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TroposphereTroposphere

Lowest layer closest to the EarthLowest layer closest to the Earth

Nearly 75% of the gases in the atmosphere Nearly 75% of the gases in the atmosphere are contained in this layer.are contained in this layer.

Temperatures generally decrease with Temperatures generally decrease with altitude.altitude.

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Troposphere (cont’d)Troposphere (cont’d)

Extends outward about 7-10 miles (11to16 Extends outward about 7-10 miles (11to16 kilometers)kilometers)

Clouds formClouds form

Most weather happens here.Most weather happens here.

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StratosphereStratosphere

Lies above the troposphere extending to Lies above the troposphere extending to about 31 miles (50 kilometers)about 31 miles (50 kilometers)

Contains the ozone layer, which protects life Contains the ozone layer, which protects life on Earth from the Sun’s harmful ultraviolet on Earth from the Sun’s harmful ultraviolet radiationradiation

Molecules of ozone absorb the radiationMolecules of ozone absorb the radiation

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Stratosphere (cont’d)Stratosphere (cont’d)

Temperatures can increase with altitude if Temperatures can increase with altitude if this layer is damaged by ozone.this layer is damaged by ozone.

Air pressure is lower than troposphere.Air pressure is lower than troposphere.

Jets cruise near the bottom of this layer.Jets cruise near the bottom of this layer.

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MesosphereMesosphere

Lies above the stratosphereLies above the stratosphere

Extends from the top of stratosphere to an Extends from the top of stratosphere to an altitude of about 50 miles (80 kilometers)altitude of about 50 miles (80 kilometers)

This is the coldest layer of the atmosphere.This is the coldest layer of the atmosphere.

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Mesosphere (cont’d)Mesosphere (cont’d)

Temperature goes down as altitude Temperature goes down as altitude increases.increases.

Meteors, or “shooting stars” burn up here.Meteors, or “shooting stars” burn up here.

Air pressure is lower than stratosphere.Air pressure is lower than stratosphere.

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ThermosphereThermosphere

Lies above the mesosphere and extends to Lies above the mesosphere and extends to outer space (90 km to 300 km)outer space (90 km to 300 km)

Temperatures are extremely high as altitude Temperatures are extremely high as altitude increases.increases.

Air pressure is lower than mesosphereAir pressure is lower than mesosphere

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Thermosphere (cont’d)Thermosphere (cont’d)

Despite high temperatures, the air would Despite high temperatures, the air would feel cold.feel cold.

Contains few molecules of airContains few molecules of air

Molecules rarely collide and thus cannot Molecules rarely collide and thus cannot transfer energy.transfer energy.

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ExosphereExosphere

Extends (300 km to more than 600 km)Extends (300 km to more than 600 km)

Air pressure is lowest in this layer.Air pressure is lowest in this layer.

Temperature increases as altitude increases.Temperature increases as altitude increases.

Many satellites orbit here.Many satellites orbit here.

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Objective: 3.01Objective: 3.01 Investigate the water cycle including Investigate the water cycle including the processes of evaporation, condensation, the processes of evaporation, condensation, precipitation, and run-off.precipitation, and run-off.

The water cycle is one of Earth’s cycles that The water cycle is one of Earth’s cycles that sustains life.sustains life.

The sun is the primary energy source that The sun is the primary energy source that powers the water cycle.powers the water cycle.

The water cycle is a vital component in the The water cycle is a vital component in the creation of weather and climate.creation of weather and climate.

The cycling of water is composed of several The cycling of water is composed of several different phases that include evaporation, different phases that include evaporation, condensation, precipitation, and run-off.condensation, precipitation, and run-off.

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Components of the Water Components of the Water CycleCycle

Water Water Storage in Storage in

OceansOceans

Water Water Storage in Storage in

Ice and Ice and SnowSnow

Snowmelt Snowmelt Runoff to Runoff to StreamsStreams

Water in the Water in the AtmosphereAtmosphere

EvaporationEvaporation SublimationSublimation SpringsSprings InfiltrationInfiltration

Surface Surface RunoffRunoff

Freshwater Freshwater StorageStorage

Ground-Ground-Water Water

StorageStorage

Ground-Water Ground-Water DischargeDischarge

CondensatioCondensationn

PrecipitationPrecipitation StreamflowStreamflow EvapotranspirationEvapotranspiration

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Water on Earth is evaporated into the air Water on Earth is evaporated into the air where it condenses and falls back to the where it condenses and falls back to the

Earth as:Earth as:

LiquidLiquid

PrecipitationPrecipitation

FrozenFrozen


MixedMixed


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EvaporationEvaporation

The change of a liquid into gas or vaporThe change of a liquid into gas or vapor

Heat from the Sun changes surface water Heat from the Sun changes surface water from a liquid to water vapor, which then from a liquid to water vapor, which then enters the atmosphere.enters the atmosphere.

Substances dissolved in the water, such as Substances dissolved in the water, such as salt, are left behind.salt, are left behind.

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CondensationCondensation

Occurs when water vapor in the atmosphere Occurs when water vapor in the atmosphere cools and changes to liquid watercools and changes to liquid water

Water vapor droplets in the atmosphere Water vapor droplets in the atmosphere become large and heavy eventually falling to become large and heavy eventually falling to the ground.the ground.

The water falls to Earth as precipitation.The water falls to Earth as precipitation.

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PrecipitationPrecipitation Precipitation occurs when clouds loose Precipitation occurs when clouds loose

water.water. Solid or liquid moisture falling from the sky is Solid or liquid moisture falling from the sky is

precipitation.precipitation. Water that moves from the atmosphere to Water that moves from the atmosphere to

the land in the form of rain, snow, sleet, or the land in the form of rain, snow, sleet, or hailhail

The type of precipitation depends on the The type of precipitation depends on the temperature of the air that the water falls temperature of the air that the water falls through.through.

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Precipitation (cont.)Precipitation (cont.)

Air above freezing-precipitation will most Air above freezing-precipitation will most likely be rain.likely be rain.

Air below freezing-precipitation will most Air below freezing-precipitation will most likely be snow.likely be snow.

Different temperature layers exist within the Different temperature layers exist within the air.air.

If snow falling from a high cloud passes If snow falling from a high cloud passes through a warmer layer-snow could melt into through a warmer layer-snow could melt into rain.rain.

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Precipitation (cont.)Precipitation (cont.)

If rain passes through another layer that’s If rain passes through another layer that’s colder near the ground-it becomes sleet.colder near the ground-it becomes sleet.

Hail is also the result of water passing Hail is also the result of water passing through different temperature layers.through different temperature layers.

Water can be found in all three states-- Water can be found in all three states-- solid, liquid and gas-- at normal solid, liquid and gas-- at normal temperatures and pressures.temperatures and pressures.

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RunoffRunoff

Runoff is all the remaining water that moves Runoff is all the remaining water that moves over the Earth’s surface.over the Earth’s surface.

The force of a falling raindrop can loosen The force of a falling raindrop can loosen and pick up soil particles.and pick up soil particles.

As water moves over land, it carries As water moves over land, it carries particles with it.particles with it.

Because of gravity, runoff and the material it Because of gravity, runoff and the material it contains move downhill.contains move downhill.

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Objective: 3.02Objective: 3.02 Discuss and determine how the Discuss and determine how the following are affected by predictable patterns of weather: following are affected by predictable patterns of weather: Temperature, Wind direction and speed, Precipitation, Temperature, Wind direction and speed, Precipitation, Cloud cover, and Air pressure.Cloud cover, and Air pressure.

Climate is predictable patterns of weather over time.Climate is predictable patterns of weather over time. Climate refers to the long-term weather patterns for a Climate refers to the long-term weather patterns for a

given area.given area. Climates can experience long-term and short-term Climates can experience long-term and short-term

changes.changes. Short-term changes include seasons, caused by Short-term changes include seasons, caused by

Earth’s tilted axis and El NiEarth’s tilted axis and El Niñño.o. El NiEl Niñño is caused by periodic temperature changes in o is caused by periodic temperature changes in

the southern Pacific Ocean, resulting in extreme the southern Pacific Ocean, resulting in extreme weather from flooding to drought. weather from flooding to drought.

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Weather ConceptsWeather Concepts

Weather depends on the elements of Weather depends on the elements of temperature, air pressure, wind, and temperature, air pressure, wind, and moisture.moisture.

Weather is not random.Weather is not random. Weather occurs in predictable patterns.Weather occurs in predictable patterns. The degree of heating and cooling of the The degree of heating and cooling of the

Earth’s surface is a result of interactions of Earth’s surface is a result of interactions of various atmospheric factors to influence various atmospheric factors to influence different patterns of weather.different patterns of weather.

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Factors Affecting ClimateFactors Affecting Climate

Latitude, the distance north or south of the Latitude, the distance north or south of the equator, influences climate mainly.equator, influences climate mainly.

Proximity of large bodies of waterProximity of large bodies of water

AltitudeAltitude

The presence of mountainsThe presence of mountains

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World ClimateZones Affecting

Climate

Tropical Zones

TemperateZones

PolarZones

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World Climate ZonesWorld Climate Zones

Tropical ZonesTropical Zones

• Located between 23.5Located between 23.5°° north and south of the north and south of the equatorequator

• Receive direct or nearly direct sunlight year roundReceive direct or nearly direct sunlight year round

• Have temperatures that are warm year-roundHave temperatures that are warm year-round

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World Climate Zones (cont’d)World Climate Zones (cont’d)

Temperate ZonesTemperate Zones

Located between 23.5Located between 23.5°° and 66.5 and 66.5°° north and south north and south of the equatorof the equator

Receive the sun’s rays more directly in the Receive the sun’s rays more directly in the summer; In winter, the sun’s rays strike at a lower summer; In winter, the sun’s rays strike at a lower angle.angle.

Weather ranges from warm or hot in the summer Weather ranges from warm or hot in the summer to cool or cold in the winter.to cool or cold in the winter.

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World Climate Zones (cont’d)World Climate Zones (cont’d)

Polar ZonesPolar Zones

Located from 66.5Located from 66.5°° north and south of the north and south of the equator to the polesequator to the poles

Receive little direct sunlight since the sun’s Receive little direct sunlight since the sun’s rays strike at a lower angle near the polesrays strike at a lower angle near the poles

Areas near both poles have cold climates.Areas near both poles have cold climates.

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Temperature ConceptsTemperature Concepts

Temperature indicates the relative warmth Temperature indicates the relative warmth or coolness of a substance as measured by or coolness of a substance as measured by thermometers.thermometers.

Temperature is measured in degrees.Temperature is measured in degrees. Most people in the United States measure Most people in the United States measure

temperature using the Fahrenheit scale.temperature using the Fahrenheit scale. The Celsius scale is commonly used to The Celsius scale is commonly used to

measure temperature in other parts of the measure temperature in other parts of the world.world.

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TemperatureTemperature Concepts (cont.) Concepts (cont.)

The Fahrenheit scale was named after Gabriel D. The Fahrenheit scale was named after Gabriel D. Fahrenheit from Germany who lived from 1686 to Fahrenheit from Germany who lived from 1686 to 1735. He devised a way of measuring temperature. 1735. He devised a way of measuring temperature. He put mercury inside a glass tube and marked 180 He put mercury inside a glass tube and marked 180 degrees between the freezing and boiling points of degrees between the freezing and boiling points of water. His scale goes from 32 to 212 degreeswater. His scale goes from 32 to 212 degrees

Anders Celsius, from Sweden, developed the Anders Celsius, from Sweden, developed the temperature scales most often used today. Celsius temperature scales most often used today. Celsius marked 100 degrees between the freezing and marked 100 degrees between the freezing and boiling points of water. His scale goes from 0 to 100 boiling points of water. His scale goes from 0 to 100 degrees.degrees.

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Wind ConceptsWind Concepts

Wind is air in motion caused by uneven Wind is air in motion caused by uneven heating. heating.

Wind is caused by air moving from an Wind is caused by air moving from an area of high pressure to one of low area of high pressure to one of low pressure.pressure.

The greater the distance between the The greater the distance between the areas, the stronger the wind. areas, the stronger the wind.

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Wind Concepts (cont’d)Wind Concepts (cont’d)

Winds are named for the direction from Winds are named for the direction from which the wind blows.which the wind blows.

Wind usually blows from the same direction.Wind usually blows from the same direction.

There is a general pattern to air circulation There is a general pattern to air circulation on Earth since the equator is constantly hot on Earth since the equator is constantly hot and the poles are cold.and the poles are cold.

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Please review Science Objective Please review Science Objective 3.01 for previous precipitation 3.01 for previous precipitation concepts.concepts.

Review slides 19, 20, and 21 for Review slides 19, 20, and 21 for precipitation content.precipitation content.

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Cloud Cover ConceptsCloud Cover Concepts

Cloud cover is the amount of sky covered by Cloud cover is the amount of sky covered by clouds.clouds.

Clouds are formed when air containing water Clouds are formed when air containing water vapor starts to condense into droplets of moisture.vapor starts to condense into droplets of moisture.

Cloudiness or cloud cover is one of the variables Cloudiness or cloud cover is one of the variables of climate.of climate.

There are different types of clouds that may cover There are different types of clouds that may cover all or parts of the sky.all or parts of the sky.

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Cloud Cover Concepts (cont’d)Cloud Cover Concepts (cont’d)

The amount of cloud cover is determined by The amount of cloud cover is determined by estimating the percentage of the sky estimating the percentage of the sky covered with clouds.covered with clouds.

Clear (0% - 5%)Clear (0% - 5%)Partly Cloudy (5% - 50%)Partly Cloudy (5% - 50%) Mostly Cloudy (50% - 95%)Mostly Cloudy (50% - 95%)Overcast (95% - 100%)Overcast (95% - 100%)

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Air Pressure ConceptsAir Pressure Concepts

Air pressure is the weight of air particles pressing Air pressure is the weight of air particles pressing down on the surface of the Earth.down on the surface of the Earth.

Air pressure may be high or low. Air pressure Air pressure may be high or low. Air pressure lessens as you move higher up in the atmospherelessens as you move higher up in the atmosphere

The higher you are, the less air is above you.The higher you are, the less air is above you. Less air is pushing down on you, so the air Less air is pushing down on you, so the air

pressure is lower.pressure is lower. Air temperature affects air pressure.Air temperature affects air pressure.

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Air Pressure (cont.)Air Pressure (cont.)

A high pressure system is associated with A high pressure system is associated with cooler temperatures and clear skies.cooler temperatures and clear skies.

A high pressure system forms where cool A high pressure system forms where cool air sinks.air sinks.

A low pressure system is associated with A low pressure system is associated with warmer weather, storms, or precipitation.warmer weather, storms, or precipitation.

An instrument called a barometer measures An instrument called a barometer measures air pressure.air pressure.

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Air Pressure (cont.)Air Pressure (cont.)

Air pressure is often stated in inches of mercury Air pressure is often stated in inches of mercury since we measure the height of mercury in the since we measure the height of mercury in the tube in inches.tube in inches.

Normal air pressure readings vary from 29 to 31.Normal air pressure readings vary from 29 to 31. Quick changes in air pressure often mean a Quick changes in air pressure often mean a

change in weather is about to occur.change in weather is about to occur. You’ll often hear or read about Barometric You’ll often hear or read about Barometric

pressure during local weather reports because of pressure during local weather reports because of quick changes in air pressure. quick changes in air pressure.

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Objective 3.03: Objective 3.03: Describe and analyze the formation of Describe and analyze the formation of various types of clouds and discuss their relation to various types of clouds and discuss their relation to weather systems.weather systems.

Clouds are made of tiny vapors of water.Clouds are made of tiny vapors of water. A cloud is the result of invisible water vapor A cloud is the result of invisible water vapor

in the air becoming visible.in the air becoming visible. Visible water vapor in the air is clouds; Visible water vapor in the air is clouds;

visible water vapor near the Earth is fog or visible water vapor near the Earth is fog or mist.mist.

There are different types of clouds which There are different types of clouds which signal different kinds of information about signal different kinds of information about the weather.the weather.

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Three basic types of clouds Three basic types of clouds form in the skies:form in the skies:

CirrusCirrus

CumulusCumulus

StratusStratus

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Different Types of CloudsDifferent Types of Clouds

CirrusCirrus In Latin, cirrus means curlIn Latin, cirrus means curl

Feathery-like plumes and wispyFeathery-like plumes and wispy

Very high in the atmosphere Very high in the atmosphere where the air is very cold where the air is very cold (over 20,000 ft)(over 20,000 ft)

Clouds of ice crystals usually Clouds of ice crystals usually associated with fair weather, associated with fair weather, but may sometimes indicate but may sometimes indicate that storms are on the waythat storms are on the way

StratusStratusLatin word for layer or blanketLatin word for layer or blanket

Low altitude clouds (below 10,000 Low altitude clouds (below 10,000 feet)feet)

Form a layer that can cover the Form a layer that can cover the entire sky like a blanketentire sky like a blanket

Rain and drizzle associatedRain and drizzle associated

If they lift quickly in the morning, If they lift quickly in the morning, they often mean a fine day they often mean a fine day aheadahead

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Different Types of Clouds Different Types of Clouds (cont.)(cont.)

CumulusCumulusLatin for heap (low clouds-Latin for heap (low clouds-

under 10,000 feet)under 10,000 feet)Usually associated with fair Usually associated with fair

weatherweatherCan produce precipitation if Can produce precipitation if

they are very tallthey are very tallDense, white puffy, cotton Dense, white puffy, cotton

like, thicklike, thickWhen large and bunched, When large and bunched,

they can cause heavy they can cause heavy showersshowers

CumulonimbusCumulonimbusUsually suggest bad weather Usually suggest bad weather

conditionsconditionsHuge, grey, and towering Huge, grey, and towering

clouds up to 60,000 feetclouds up to 60,000 feetCan bring rain, sleet, hail, Can bring rain, sleet, hail,

thunder, lightning, and thunder, lightning, and tornadoestornadoes

The top of the cloud is often The top of the cloud is often anvil-shapedanvil-shaped

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NimbostratusNimbostratus

Low dark sheets of clouds Low dark sheets of clouds under 10,000 feetunder 10,000 feet

Blot out the sunBlot out the sun

Often followed by lengthy Often followed by lengthy precipitation within a few precipitation within a few

hourshours

StratocumulusStratocumulus

Low rolling mass of clouds Low rolling mass of clouds under 10,000 feetunder 10,000 feet

Thin lumpy gray to white Thin lumpy gray to white cloudsclouds

May produce light May produce light precipitation that usually precipitation that usually dissipates by the end of dissipates by the end of the daythe day

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AltocumulusAltocumulus

Larger than cirrocumulus Larger than cirrocumulus cloudsclouds

Middle clouds between Middle clouds between 10,000 to 20,000 feet10,000 to 20,000 feet

Patterned white to gray Patterned white to gray clouds that are often clouds that are often rippled or appear in wavesrippled or appear in waves

Considered fair weather that Considered fair weather that often follow stormsoften follow storms

AltostratusAltostratus

Formless gray to bluish Formless gray to bluish cloudsclouds

Middle clouds between Middle clouds between 10,000 to 20,000 feet10,000 to 20,000 feet

Form a thin veil over the sun Form a thin veil over the sun and moonand moon

If these clouds gradually If these clouds gradually darken and blot out the darken and blot out the sun or moon, precipitation sun or moon, precipitation will follow will follow

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CirrostratusCirrostratusHigh clouds over 20,000 feetHigh clouds over 20,000 feetMilky, white-veined cloudsMilky, white-veined cloudsProduce a halo around the Produce a halo around the

sun or moonsun or moonOften called “bed-sheet Often called “bed-sheet

cloudscloudsIf clouds are replaced by If clouds are replaced by

cirrostratus clouds it cirrostratus clouds it usually means usually means precipitation will followprecipitation will follow

CirrocumulusCirrocumulusHigh clouds over 20,000 feetHigh clouds over 20,000 feetAppear in layers that look like Appear in layers that look like

rippled sand or fish scalesrippled sand or fish scalesNicknamed “mackerel sky”Nicknamed “mackerel sky”Considered an omen of good Considered an omen of good

weatherweather

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Contrail Contrail

Thin high altitude clouds Thin high altitude clouds over 20,000 feetover 20,000 feet

Formed when moisture Formed when moisture released from jet released from jet engines turns into ice engines turns into ice crystalscrystals

Swelling CumulusSwelling Cumulus

Flat bottomed towering Flat bottomed towering clouds up to 60,000 clouds up to 60,000 feetfeet

Have growing, Have growing, cauliflower-like towerscauliflower-like towers

Often form in midday and Often form in midday and precede precede cumulonimbus cloudscumulonimbus clouds

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Visual OpacityVisual Opacity

The thickness of a cloud determines the amount of The thickness of a cloud determines the amount of light being transmitted through the cloud.light being transmitted through the cloud.

Visual opacity can be described as:Visual opacity can be described as:

OpaqueOpaque

TranslucentTranslucent

TransparentTransparent

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Objective 3.04Objective 3.04 Explain how global Explain how global atmospheric patterns affect local weatheratmospheric patterns affect local weather

When cool and warm When cool and warm air collide, wind is air collide, wind is created.created.

The collision causes The collision causes warm air to rise.warm air to rise.

When air rises it gets When air rises it gets cooler.cooler.

Cooler air causes the Cooler air causes the water vapors in the water vapors in the atmosphere to atmosphere to condense or form condense or form water droplets.water droplets.

Cool air can not hold Cool air can not hold as much moisture as as much moisture as warm air.warm air.

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Global Atmospheric Patterns Global Atmospheric Patterns (cont.)(cont.)

There are many types of wind patterns that affect There are many types of wind patterns that affect global weather patterns.global weather patterns.

The wind pattern that affects our state are the The wind pattern that affects our state are the Prevailing Westerlies named so because they Prevailing Westerlies named so because they blow in from the west.blow in from the west.

The Prevailing Westerlies move weather from west The Prevailing Westerlies move weather from west to east. to east.

Weather in your area may be different from Weather in your area may be different from weather in another part of the state or country.weather in another part of the state or country.

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Four Major Types of Air Masses Four Major Types of Air Masses Influence Weather in North AmericaInfluence Weather in North America

Cold and DryCold and Dry

Hot and DryHot and Dry

Cool and moistCool and moist

Warm and MoistWarm and Moist

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Cold and Dry Air MassesCold and Dry Air Masses

Continental PolarContinental Polar air masses bring cool or air masses bring cool or cold air in winter. cold air in winter.

Form over central and northern Canada and Form over central and northern Canada and AlaskaAlaska

Air masses that form near the Arctic Circle Air masses that form near the Arctic Circle can bring bitterly cold weather with very low can bring bitterly cold weather with very low humidity.humidity.

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Hot and Dry Air MassesHot and Dry Air Masses

Continental TropicalContinental Tropical air masses form only air masses form only in summer over dry areas of the Southwest in summer over dry areas of the Southwest and northern Mexico.and northern Mexico.

Cover a smaller area than other air masses.Cover a smaller area than other air masses.

Occasionally move northeast, bringing hot Occasionally move northeast, bringing hot dry weather to the southern Great Plains.dry weather to the southern Great Plains.

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Cool and Moist Air MassesCool and Moist Air Masses

Maritime PolarMaritime Polar air masses form over the icy air masses form over the icy cold North Pacific and North America.cold North Pacific and North America.

They affect the West Coast more than the They affect the West Coast more than the East Coast.East Coast.

These air masses usually bring fog, rain, These air masses usually bring fog, rain, and cool temperatures to the West Coast.and cool temperatures to the West Coast.

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Warm and Moist Air MassesWarm and Moist Air Masses

Maritime TropicalMaritime Tropical air masses form over oceans air masses form over oceans near the tropics.near the tropics.

When these air masses form over the Gulf of When these air masses form over the Gulf of Mexico and the Atlantic Ocean, they move first Mexico and the Atlantic Ocean, they move first into the southeastern United States.into the southeastern United States.

Then these air masses then move north and Then these air masses then move north and northeast, where they influence weather in the northeast, where they influence weather in the central and eastern United States.central and eastern United States.

Hot humid weather is usually associated with Hot humid weather is usually associated with maritime tropical air masses in the summer.maritime tropical air masses in the summer.

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FrontsFronts

A front is an area where the air masses A front is an area where the air masses meet and do not mix.meet and do not mix.

Two air masses meet with different Two air masses meet with different temperatures and densities.temperatures and densities.

When air masses meet at a front, the When air masses meet at a front, the collision often causes storms and collision often causes storms and changeable weather.changeable weather.

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Four Types of FrontsFour Types of Fronts

Cold FrontsCold Fronts

Warm FrontsWarm Fronts

Stationary FrontsStationary Fronts

Occluded FrontsOccluded Fronts

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Cold FrontsCold Fronts

Cold fronts move quickly, so they can cause Cold fronts move quickly, so they can cause abrupt weather changes including violent abrupt weather changes including violent storms.storms.

Cool dry air moves in an area after a cold Cool dry air moves in an area after a cold front passes through.front passes through.

Cold air is dense and tends to sink. Cold air is dense and tends to sink. Denser cold air slides under the lighter Denser cold air slides under the lighter

warm air.warm air.

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Warm FrontsWarm Fronts

Clouds, storms, and rain also accompany Clouds, storms, and rain also accompany warm fronts.warm fronts.

If warm air is humid, showers and light rain If warm air is humid, showers and light rain fall along the front where warm and cold fall along the front where warm and cold meet.meet.

Warm fronts move more slowly than cold Warm fronts move more slowly than cold fronts. In winter, warm fronts bring snow. fronts. In winter, warm fronts bring snow.

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Stationary FrontsStationary Fronts

A front is stationary when a warm front and a cold A front is stationary when a warm front and a cold front doesn’t have enough force to move the other.front doesn’t have enough force to move the other.

If a stationary front remains stalled over an area, it If a stationary front remains stalled over an area, it may bring many days of clouds and precipitation.may bring many days of clouds and precipitation.

When the warm and cold air meet, water vapor in When the warm and cold air meet, water vapor in the warm air condenses into rain, snow, fog, or the warm air condenses into rain, snow, fog, or clouds.clouds.

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Occluded FrontsOccluded Fronts

At an occluded front, a warm air mass is caught At an occluded front, a warm air mass is caught between two cooler air masses.between two cooler air masses.

When a cold air mass and a cool air mass come When a cold air mass and a cool air mass come together, the warm air mass caught between them together, the warm air mass caught between them is forced upward.is forced upward.

The result of the mix is an occluded front.The result of the mix is an occluded front. The warm air mass is cut off from the ground. As it The warm air mass is cut off from the ground. As it

cools and its water vapor condenses, the weather cools and its water vapor condenses, the weather may turn cloudy and rainy or snowy.may turn cloudy and rainy or snowy.

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Objective 3.05Objective 3.05 Compile and use weather data to Compile and use weather data to

establish a climate record and reveal any trends.establish a climate record and reveal any trends.

Weather can be observed and information about weather Weather can be observed and information about weather can be collected, measured, recorded, analyzed and can be collected, measured, recorded, analyzed and presented.presented.

Weather information is collected and analyzed using many Weather information is collected and analyzed using many different tools, techniques, and strategies. (Including maps, different tools, techniques, and strategies. (Including maps, charts, computers, satellites, balloons, and storm chasers).charts, computers, satellites, balloons, and storm chasers).

Forecasts about weather are made on short range and Forecasts about weather are made on short range and extended forecasts.extended forecasts.

Predictions about weather are based on historical climate Predictions about weather are based on historical climate trends and current data which is updated regularly as more trends and current data which is updated regularly as more information is received.information is received.

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Tools Used to Collect Weather DataTools Used to Collect Weather Data

Ordinary radar is able to report location and Ordinary radar is able to report location and strength of precipitation.strength of precipitation.

Doppler Radar indicates wind direction, wind Doppler Radar indicates wind direction, wind speed, and boundaries between warm fronts and speed, and boundaries between warm fronts and cold fronts as well as location and strength of cold fronts as well as location and strength of precipitation.precipitation.

Observational tools such as satellites, Observational tools such as satellites, dropsondes, weather stations, weather buoys, dropsondes, weather stations, weather buoys, ships, and airplanes are sources of weather data.ships, and airplanes are sources of weather data.

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Weather Data Collection (cont.)Weather Data Collection (cont.)

Weather stations and buoys record various weather Weather stations and buoys record various weather parameters at fixed locations.parameters at fixed locations.

Ships and airplanes are moving weather stations recording Ships and airplanes are moving weather stations recording data at their current position.data at their current position.

After being launched from balloons or airplanes, 1800 After being launched from balloons or airplanes, 1800 dropsondes collect weather data as they drop through the dropsondes collect weather data as they drop through the sky each day.sky each day.

Satellites are important sources of weather data. Satellites are important sources of weather data. Data from all these sources are channeled into a Data from all these sources are channeled into a

supercomputer at a central location to make weather supercomputer at a central location to make weather predictions that take into account the current weather.predictions that take into account the current weather.

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Weather Data Collection (cont.)Weather Data Collection (cont.)

SupercomputersSupercomputers Use numerical forecasting or mathematical Use numerical forecasting or mathematical

calculations to predict weathercalculations to predict weather Perform many calculations that take into account Perform many calculations that take into account

such as air pressure differences, solar radiation, such as air pressure differences, solar radiation, the Earth’s rotation, the water cycle, as well as the Earth’s rotation, the water cycle, as well as current informationcurrent information

Allow forecasters to generate more accurate Allow forecasters to generate more accurate forecasts based on a comprehensive regional forecasts based on a comprehensive regional perspective about current weatherperspective about current weather

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Weather Data Collection ToolsWeather Data Collection Tools

BarometerBarometer

AnemometerAnemometer

Wind VaneWind Vane

PsychrometerPsychrometer

ThermometerThermometer

Rain GaugeRain Gauge

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Weather Data Collection Tools (cont.)Weather Data Collection Tools (cont.)

BarometerBarometer

Measures air pressureMeasures air pressure

Sometimes referred to as Sometimes referred to as barometric pressurebarometric pressure

The pressure of the air on the The pressure of the air on the pool of mercury causes pool of mercury causes the mercury to rise in a the mercury to rise in a tube.tube.

The height of the mercury in The height of the mercury in the tube is measured in the tube is measured in inches. inches.

Anaeroid BarometerAnaeroid Barometer

Doesn’t contain mercuryDoesn’t contain mercury

The air pressure on this The air pressure on this box causes it to box causes it to change shape, moving change shape, moving the needle on the the needle on the gauge that indicates gauge that indicates air pressure. air pressure.

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AnemometerAnemometer

Measures wind speed Measures wind speed

Wind pushes small cups and Wind pushes small cups and makes part of the makes part of the anemometer spin.anemometer spin.

The faster the wind blows, The faster the wind blows, the faster the cup spins.the faster the cup spins.

Counts how many turns the Counts how many turns the cups make in a certain cups make in a certain time. The dial then shows time. The dial then shows the wind speed.the wind speed.

Wind VaneWind VaneShows from which direction Shows from which direction

the wind is blowingthe wind is blowingLetters on the wind vane Letters on the wind vane

show which way is north, show which way is north, south, east, and west.south, east, and west.

An arrow turns to point into An arrow turns to point into the wind.the wind.

If a wind vane’s arrow points If a wind vane’s arrow points north, that means wind is north, that means wind is blowing from the north.blowing from the north.

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Weather Data Collection Tools Weather Data Collection Tools (cont.)(cont.)

PsychrometerPsychrometerMeasures relative humidity Measures relative humidity Often called wet bulb Often called wet bulb

thermometerthermometerUses two thermometers, one bulb Uses two thermometers, one bulb

of which is covered with a wet of which is covered with a wet cloth.cloth.

As the cloth dries, the cooling As the cloth dries, the cooling effect of evaporation lowers the effect of evaporation lowers the temperature on that temperature on that thermometerthermometer

Temperatures on the two Temperatures on the two thermometers are compared thermometers are compared on a chart to find relative on a chart to find relative humidityhumidity

ThermometerThermometer

Measures air temperature via Measures air temperature via the expansion of a liquid or the expansion of a liquid or a metal as the air a metal as the air temperature changestemperature changes

Numbers on a thermometer Numbers on a thermometer are the scale.are the scale.

The scale shows the The scale shows the temperature in degrees.temperature in degrees.

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Rain GaugeRain Gauge A very simple instrument that collects rainA very simple instrument that collects rain Used to measure the amount of liquid Used to measure the amount of liquid

precipitationprecipitation The average conversion of 10 inches of The average conversion of 10 inches of

snow equals 1 inch of rain to find out how snow equals 1 inch of rain to find out how much water fell.much water fell.

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Objective 3.06Objective 3.06 Discuss and determine the influence of Discuss and determine the influence of geography on weather and climate: mountains, sea geography on weather and climate: mountains, sea breezes, and water bodies breezes, and water bodies

Geological features influence weather patterns.Geological features influence weather patterns.

Mountains and large bodies of waters such as Mountains and large bodies of waters such as oceans and huge lakes have the most affect on oceans and huge lakes have the most affect on weather patterns. weather patterns.

Wind blowing against a mountain causes the air to Wind blowing against a mountain causes the air to rise, cool, and condense. ( cool air can hold less rise, cool, and condense. ( cool air can hold less moisture than warm air).moisture than warm air).

Wind that flows over the mountain and down the Wind that flows over the mountain and down the other side causes air to become warmer and takes other side causes air to become warmer and takes up moisture through evaporation.up moisture through evaporation.

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Influence of Geography (cont.)Influence of Geography (cont.)

Land absorbs heat from the sun faster than bodies of Land absorbs heat from the sun faster than bodies of water; therefore as the warm air of the land rises, it is water; therefore as the warm air of the land rises, it is replaced by the cooler air from the water that we call sea replaced by the cooler air from the water that we call sea breezes.breezes.

Urbanization also affects weather conditions such as, it is Urbanization also affects weather conditions such as, it is typically hotter and rainier in large cities than in rural areas; typically hotter and rainier in large cities than in rural areas; factors contributing to this are: pavement, huge buildings, factors contributing to this are: pavement, huge buildings, transportation systems, factories, etc. transportation systems, factories, etc.

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Influence of Geography (cont.)Influence of Geography (cont.)

Geography is influenced by:Geography is influenced by:

MountainsMountains

Sea BreezesSea Breezes

Water BodiesWater Bodies

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MountainsMountains

Humid winds blowing from the ocean toward Humid winds blowing from the ocean toward coastal mountains causes the air to rise up to pass coastal mountains causes the air to rise up to pass over the mountain. over the mountain.

Rising warm air cools and its water vapor Rising warm air cools and its water vapor condenses forming clouds. Cool air can hold less condenses forming clouds. Cool air can hold less moisture than warm air.moisture than warm air.

Mountains in the path of prevailing winds can Mountains in the path of prevailing winds can influence where precipitation falls.influence where precipitation falls.

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Mountains (cont’d)Mountains (cont’d)

Rain or snow falls on the windward side of the Rain or snow falls on the windward side of the mountain, the side oncoming wind hits.mountain, the side oncoming wind hits.

Land on the leeward side of the mountain, the Land on the leeward side of the mountain, the downwind, has cool dry air since it has lost much downwind, has cool dry air since it has lost much of its water vapor.of its water vapor.

The leeward side of the mountain forms a rain The leeward side of the mountain forms a rain shadow, an area that doesn’t receive rain, shadow, an area that doesn’t receive rain, because a mountain range blocks the rain. because a mountain range blocks the rain.

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Sea BreezesSea Breezes

A wind that blows from the ocean onto land A wind that blows from the ocean onto land is a sea breeze.is a sea breeze.

Cool air, during the day, moves from the Cool air, during the day, moves from the sea to the land.sea to the land.

At night, the situation reverses. Land cools At night, the situation reverses. Land cools more quickly than water, so the air over land more quickly than water, so the air over land becomes cooler than the air over water. becomes cooler than the air over water.

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Water BodiesWater Bodies

Oceans are the bodies of water most often Oceans are the bodies of water most often referred to as the five oceans-Atlantic, referred to as the five oceans-Atlantic, Pacific, Arctic, Indian, and Southern.Pacific, Arctic, Indian, and Southern.

The Atlantic and Pacific oceans are divided The Atlantic and Pacific oceans are divided by the equator which in turn divides into the by the equator which in turn divides into the North and South Atlantic Ocean and the North and South Atlantic Ocean and the North and South Pacific Ocean.North and South Pacific Ocean.

A sea can be a part of an ocean or attached A sea can be a part of an ocean or attached to an ocean. to an ocean.

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Water Bodies (cont’d)Water Bodies (cont’d)

Water bodies are considered different forms Water bodies are considered different forms of flowing water.of flowing water.

There are many names for water bodies There are many names for water bodies such as: rivers, streams, lakes, bays, seas, such as: rivers, streams, lakes, bays, seas, oceans, ponds, and etc.oceans, ponds, and etc.

The water cycle (hydrologic cycle) plays a The water cycle (hydrologic cycle) plays a very important process which moves all very important process which moves all bodies of water, powered by the sun’s bodies of water, powered by the sun’s energy. energy.

1 weather and climate content goal 3: the learner will conduct investigations and use appropriate...

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