WeatherWeather

An OverviewAn Overview

AtmosphereAtmosphere

Is a mixture of the gasses that Is a mixture of the gasses that surround the Earth.surround the Earth.

The atmosphere gives us the air we The atmosphere gives us the air we breath as well as protects us from breath as well as protects us from some of the sunsome of the sun’’s harmful rays.s harmful rays.

The atmosphere is also the The atmosphere is also the location where a lot of the location where a lot of the weather phenomena that we will be weather phenomena that we will be learning about happens.learning about happens.

Air PressureAir Pressure

Is the measure of the force Is the measure of the force with which air molecules with which air molecules press on the surface.press on the surface.

When your ears pop the When your ears pop the pressure inside your ears and pressure inside your ears and outside your ears become =outside your ears become =

AltitudeAltitude

Is defined as Is defined as the height of an the height of an object above the object above the surface of the surface of the Earth. Earth.

As altitude As altitude increases air increases air pressure pressure decreasesdecreases

Why is this?Why is this?

Layers of the Layers of the atmosphereatmosphere

Based on Based on temperature the temperature the EarthEarth’’s s atmosphere is atmosphere is divided into 4 divided into 4 layerslayers

1) Troposphere1) Troposphere 2) Stratosphere2) Stratosphere 3) Mesosphere3) Mesosphere 4) Thermosphere4) Thermosphere

TroposphereTroposphere

Lowest layer of Lowest layer of the atmospherethe atmosphere

Densest Densest atmospheric layeratmospheric layer

EarthEarth’’s water s water vapor, air vapor, air pollution, clouds, pollution, clouds, weather, and life weather, and life forms are found at forms are found at this layer this layer

StratosphereStratosphere

The air is very thin The air is very thin and contains very and contains very little moisturelittle moisture

Temp approx. -60 C Temp approx. -60 C degreesdegrees

In this layer the In this layer the temperature rises temperature rises with altitude with altitude because of ozone because of ozone which is a gas that which is a gas that heats up the heats up the atmosphereatmosphere

MesosphereMesosphere

Coldest layer: Coldest layer: can be as low as can be as low as -93 degrees C-93 degrees C

Large wind Large wind storms can take storms can take place with wind place with wind speeds reaching speeds reaching more than 150 more than 150 mphmph

ThermosphereThermosphere

The upper most The upper most atmospheric layer atmospheric layer in which the in which the temperature can temperature can reach 1700 degrees reach 1700 degrees C.C.

Very few molecules Very few molecules at this layerat this layer

Picture to right Picture to right shows heat at this shows heat at this layerlayer

Heating of the Heating of the AtmosphereAtmosphere

Heating of the Heating of the atmosphere atmosphere takes places in takes places in 3 ways3 ways

1) Conduction1) Conduction 2) Convection2) Convection 3) Radiation3) Radiation

RadiationRadiation

This is a method of heat This is a method of heat transfer in which heat travels transfer in which heat travels through empty spacethrough empty space

The best example of this is the The best example of this is the suns rays heating up the Earth. suns rays heating up the Earth. The heat will travel through The heat will travel through outer space (empty) reach our outer space (empty) reach our planet and heat up the surfaceplanet and heat up the surface

ConductionConduction

Is the transfer of thermal Is the transfer of thermal energy from one material to energy from one material to another by direct contactanother by direct contact

Example would be walking on Example would be walking on the sidewalk and heating up the sidewalk and heating up your foot from the heat that your foot from the heat that has built up on the groundhas built up on the ground

ConvectionConvection

Transfer of thermal energy by Transfer of thermal energy by circulation or movement of a circulation or movement of a liquid or a gasliquid or a gas

For example: air is heated and For example: air is heated and it rises then it cools and it it rises then it cools and it sinks. This circular up and sinks. This circular up and down motion pushes atmospheric down motion pushes atmospheric gases on our planet .gases on our planet .

““The Green House The Green House EffectEffect””

This is the This is the process in process in which gases in which gases in the atmosphere the atmosphere trap thermal trap thermal energy. Keeps energy. Keeps the surface of the surface of the Earth much the Earth much warmerwarmer

Global warming: Global warming: This is when the This is when the EarthEarth’’s s averageaverage temperature temperature increases each increases each year. Average year. Average temperature is the temperature is the average of all the average of all the locations on earth locations on earth during 1 whole during 1 whole year.year.

WindWind

Is very simply defined as moving Is very simply defined as moving air.air.

It is created from differences in It is created from differences in air pressure caused by temperature air pressure caused by temperature differences.differences.

Usually there is greater pressure at Usually there is greater pressure at the poles and less at the equator. the poles and less at the equator. There fore wind usually moves from There fore wind usually moves from the poles toward the equator.the poles toward the equator.

Coriolis EffectCoriolis Effect

The curving of moving The curving of moving objects, such as wind, by the objects, such as wind, by the earthearth’’s rotation is called the s rotation is called the ““coriolis effectcoriolis effect””. .

Cont. on page 404Cont. on page 404 Read 402 - 407Read 402 - 407 Page 407 questions 1-4Page 407 questions 1-4

Types of WindsTypes of Winds

Trade Winds: winds that blow from Trade Winds: winds that blow from 30 degrees latitude to the equator30 degrees latitude to the equator

Westerlies: wind belts found in Westerlies: wind belts found in both the northern hemisphere and both the northern hemisphere and southern hemisphere between 30 - southern hemisphere between 30 - 60 degrees latitude60 degrees latitude

Polar Easterlies: wind belts from Polar Easterlies: wind belts from the poles to 60 degrees latitudethe poles to 60 degrees latitude

The Jet streamThe Jet stream

The jet stream is very high speed The jet stream is very high speed band of air that blows in the band of air that blows in the troposphere and lower stratosphere troposphere and lower stratosphere

The jet stream can reach wind The jet stream can reach wind speeds of up to 250 km / hrspeeds of up to 250 km / hr

This stream of air switches This stream of air switches direction often, and in doing so direction often, and in doing so steers storms / fronts across our steers storms / fronts across our countrycountry

Jet StreamJet Stream

PollutionPollution

Primary Primary pollutants: put pollutants: put in the air by in the air by human or human or natural natural activityactivity

Secondary Secondary Pollutants: Pollutants: This type of This type of pollutant pollutant reacts when two reacts when two primary primary pollutants pollutants react to form a react to form a new secondary new secondary pollutant pollutant

Acid PrecipitationAcid Precipitation

When fuels get burned some of When fuels get burned some of the remnants go up into the the remnants go up into the air where it mixes with water air where it mixes with water vapor and then comes down as vapor and then comes down as acid rain. This rain can acid rain. This rain can weather metal, wood (ect.) at weather metal, wood (ect.) at and advanced rate.and advanced rate.

Ex. Statue of liberty, BridgesEx. Statue of liberty, Bridges

AssignmentAssignment

In the past few decades In the past few decades Pollution has become a major Pollution has become a major problem for our country. Please problem for our country. Please write an essay stating what you write an essay stating what you would do if you had an unlimited would do if you had an unlimited budget and where in charge of budget and where in charge of environmental policies in our environmental policies in our country. How would you go about country. How would you go about fixing this major problem?fixing this major problem?

Water CycleWater Cycle

This relates to the This relates to the continuous movement of water continuous movement of water from lakes / rivers to clouds from lakes / rivers to clouds to the ground and back up to the ground and back up againagain

Vocabulary: condensation / Vocabulary: condensation / vaporizationvaporization

HumidityHumidity

Is defined as the amount of Is defined as the amount of water vapor or moisture in water vapor or moisture in the air.the air.

relative humidity: Is the relative humidity: Is the amount of moisture in the air amount of moisture in the air compared to the maximum compared to the maximum amount of humidity it can amount of humidity it can hold at a certain temperaturehold at a certain temperature

Dew PointDew Point

Is defined as the temperature Is defined as the temperature air must cool to be air must cool to be completely saturated. completely saturated.

CloudsClouds

A cloud is a collection of A cloud is a collection of millions of tiny little water millions of tiny little water droplets or ice crystals droplets or ice crystals which are suspended in the which are suspended in the airair

In this next section we are In this next section we are going to learn about the going to learn about the different types of cloudsdifferent types of clouds

Cumulus CloudsCumulus Clouds

Puffy white cloud that tend to Puffy white cloud that tend to have a white bottom ( cotton have a white bottom ( cotton balls)balls)

These clouds form when warm air These clouds form when warm air risesrises

They usually represent good They usually represent good weather, unless they get very weather, unless they get very large they can represent large they can represent thunderstormsthunderstorms

Stratus cloudsStratus clouds

This type of cloud forms in layersThis type of cloud forms in layers This type of clouds covers large areas This type of clouds covers large areas of the sky usually blocking out the of the sky usually blocking out the sunsun

Caused by a gentle lifting of a large Caused by a gentle lifting of a large body of air into the atmospherebody of air into the atmosphere

NIMBOSTRATUS: clouds that are stratus NIMBOSTRATUS: clouds that are stratus in origin however dark in color. They in origin however dark in color. They usually produce light to heavy rainusually produce light to heavy rain

Cirrus CloudsCirrus Clouds

Thin feathery white clouds Thin feathery white clouds formed at high altitudesformed at high altitudes

These types of clouds form These types of clouds form when the wind is strongwhen the wind is strong

They may represent bad They may represent bad weather If they begin to weather If they begin to thicken and lower in altitudethicken and lower in altitude

PrecipitationPrecipitation

Is water in liquid or solid form Is water in liquid or solid form that forms from the sky to the that forms from the sky to the surface of the Earthsurface of the Earth

There are four major types of There are four major types of precipitationprecipitation

Rain, Sleet, Snow, HailRain, Sleet, Snow, Hail In order for a cloud droplet to In order for a cloud droplet to form as precipitation it must form as precipitation it must increase itincrease it’’s size 100 timess size 100 times

Snow / SleetSnow / Sleet

Snow forms when water vapor is so Snow forms when water vapor is so cold that it falls in solid form cold that it falls in solid form as snowas snow

Sleet forms when rain falls Sleet forms when rain falls through a layer of freezing airthrough a layer of freezing air

If the rain does not freeze till If the rain does not freeze till it hits the surface then it forms it hits the surface then it forms something called glaze or (ground something called glaze or (ground ice)ice)

HailHail

Solid precipitation that forms Solid precipitation that forms as balls or lumps of iceas balls or lumps of ice

Usually forms when gust of air Usually forms when gust of air carries rain droplets to a carries rain droplets to a high ,, cold altitude where it high ,, cold altitude where it freezes and then falls to the freezes and then falls to the Earth as a ball of ice called Earth as a ball of ice called hailhail