Atmosphere and Weather-8th Grade- Revised

8/10/2019 Atmosphere and Weather-8th Grade- Revised

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Life science 5.4.8.E.1 5.4.8.F.1

5.4.8.F.2 & F.3


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arth

Science

Atmosphere


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The Air Around You Earth's atmosphereis the envelope of gases that surrounds

the planet. made up of mostly of nitrogen, oxygen, with a

small amount of carbon dioxide, water vapor, andmany other gases, as well as particles of liquidsand solids

Weatheris the condition of Earth's atmosphere


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Air Pressure

Air pressure is the result ofthe weight of a column of airpushing down on an area. Airpressure is measured in Mb ormillibars

101!"# millibars

1 in x 1 in

square

column of

air weighs

14.7 lbs at

sea level


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Measuring Air Pressure

barometeris an instrument that is used tomeasure air pressure. mercury barometer consists of a glass tube

open at the bottom end and partially filled

with mercury

aneroid barometer has an airtight metalchamber


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Air Pressure $ Altitude

Elevation the distance above sea level. As altitude increasesAir pressure decreases

As air pressure decreases, so does density.


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"o #ow$ #ame the 4 a!ers of theatmosphere an% te me which one isso %ense that it can burn up

meteoroids thus sa'in( us fromcertain %eath )we ma!be not*

+,-T/ E0pain how ener(! fromthe sun aects our atmosphere


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'nergy in 'arth(sAtmosphere Energy travels to Earth as electromagnetic radiation from

the Sun

EMR travels through the atmosphere heats the surface

of the Earth

!hen Earth"s surface is heated, it radiates most of the

energy bac# into the atmosphere as infrared radiation.


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8eat Transfer in theAtmosphere Thermal energy - total energy of motion in the particles of

a substance Temperature the average thermal energy of the

substance particles Heat - transfer of thermal energy from a hotter obect to a

cooler one !ransferred in " of # ways$

%adiation &onduction &onvection


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9inds !ind is the movement of air from

an area of high pressure to an

area of lower pressure. Winds are caused by

dierences in air pressurecaused by unequal heating of theatmosphere
http://www.brainpop.com/science/weather/wind/http://www.brainpop.com/science/weather/wind/


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Wind Direction / WindSpeed Wind speed is measured with ananemometer! The name of a wind tells

you the direction the

wind is coming from.


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"o #ow$ f !ou were %own at the#ew erse! shore for the wee an%obser'e% the chan(e in

temperatures %urin( the %a! an% atni(ht when in the 24 hours of a %a!wou% the air o'er the 6cean be

warmer then the an%7 n% wh!7 +,-T/ +tate how scientist %escribe

an% e0pain win%s . n% wi be abe

to %entif! where the maor (oba


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Sea bree$es %and bree$es are Local Winds

caused by the une&ual heating of Earth"s surface

within a small area


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:oriolis ';ect Because Earth is rotating, global winds do not follow a straight path.

The way Earth's rotation makes winds curve is called the&orioliseect. In the Northern Hemisphere, global winds curve to the right.In the Southern Hemisphere, global winds curve to the left.
http://www.youtube.com/watch?v=rdGtcZSFRLkhttp://www.youtube.com/watch?v=rdGtcZSFRLk


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>et &tream

?i(h spee% win%currents about15: mph that are1:/15 m abo'ethe surface


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The Water CycleEvaporationCondensationPrecipitationRunoff


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Humidity vs. Relative

Humidity Humidityis the amount of water

vapor in the air. Relative Humidity- The amount

of water vapor the air can hold ata certain temperature

Saturation The maximumwater vapor air can hold at acertain temperature. Warmair holds more water thancold air, beyond this point itrains!

Psychrometer: device w/two thermometers, one w/ awet bulb the other w/ a drybulb.

Warm air

holds morewater vaporthan coldair!


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"o #ow$ f !ou i'e% in the #orth;oe what t!pe of win%s wou% beoccurrin( in the oceans that

surroun% !ou7 ;oar Easteries


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Relative Humidity Dry Bulb Temperature

The dry bulb temperature is the air temperaturemeasured using a standard thermometer. t is the

temperature reported in daily weather forecasts and

is sometimes referred to as the ambient air

temperature.

Wet Bulb Temperature

The wet bulb temperature also uses a standard thermometerhowever, a wet piece of cloth covers the bulb of the thermometer."s air passes over the wet cloth, the water in the clothevaporates, drawing heat out of the thermometer. #cools it$


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How Clouds Form Dew Point The dew point temperature is the

temperature at which the air can no longer hold all of

its water vapor, and some of the water vapor must

condense into liquid water.


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3 Main Cloud Types

>umuus

>irrus

+tratus


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Cloud Types - Photos

atocumuus stratocumuus nimbostratus

cumuus stratus cirrus

cumuonimbusstratonimbus

cirrocumuus


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"o #ow$ f !ou saw a cou% (oin(strai(ht up )'ertica* that oos iean'i in the s! what t!pe ofweather wou% !ou e0cept to seesoon7

Thun%erstorm +,-T/ %entif! the common t!pes

of precipitation an% %escribe how

the! are measure%


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Precipitation Rain most common type of precipitation, smaller droplets are drizzle or

mist. Hail forms only in cumulonimbus clouds during thunderstorms.


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Precipitation Snow water vapor converted directly into ice crystals, all are six sided and unique in shape.

Sleet- as rain falls to the ground it sometimes hits layers of cold air below freezing. Freezing rain rain (water) that hits very cold ground structures on the surface freezes.

see

t

FreeAin(Bain


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4 Main ir Masses !uge "od# of air t!at !as similar temperature$ !umidit# and air

pressure Tropical warm air masses lower pressure

Polar cold air masses higher pressure

ontinental form over land therefore are low

in humidity, dry air

"aritime forms over the water therefore is high

in humidity

1orth "merican "ir 2asses


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How ir Masses Move !revailing "esterlies and the Trade winds

#et $tream high speed winds blowing from "est to the %ast about &' m high


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"o #ow / ?ow %o air masses of%ierent %ensities beha'e7 Tae aoo at this openin(

%emonstrationC.-ase% on what !ouwatch/ write a h!pothesis statin(what wou% happen if a mass of co%

air ran into a mass of warm air

+,-T/ "e'eop a h!pothesis on

what occurs when a co% front an%


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Front- the boundary where two air masses meet. They do not mix easily.

ess dense air masses push over top of heavier more dense fronts. $torms and weather changes occur at fronts

Types of *ronts

+old *ront,

"arm *ront $tationary *ront

ccluded *ronts

,arm Front

>o% Front 6ccu%e% Front


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Warm Fronts

a% &arm Front warm front moving faster than a cold front, over taes it

and pushes up over the cold front. ("arm air less dense than cold air and-floats on the cold air mass).


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Cold Fronts old #ront When 3apidly moving old 2ass collides

w/ slow moving warm air mass, the more dense cold airslides under the warmer air mass.

"s warm air is pushed up higher, the air begins tocool holds less water vapor precipitation occurs.

>o%Front


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Cyclones


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Cyclones C#clone associated w/ ow pressure systems. "arm winds at the center rise

spin upward in a counterclocwise direction (if you were looing from above)

associated w/ decreasing air pressure, clouds, wind precipitation


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Types of Fronts

Front How Forms Type of Weather

>o% Front

,arm Front

6ccu%e% Front

+tationar! Front

Storm ( a violent distur"ance in t!e


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Storm a violent distur"ance in t!e

atmosp!ere% )!understorm a small storm w/ heavy precipitation Thunder and lightning.

a. *orm in +umulonimbus clouds called thunderheads.

"% *ig!tning $tatic electricity build up w/ electrical discharge 0umping betweenclouds or the clouds the ground.

c% )!under caused from the rapid expansion of air after lightning bolt ( 1','''

degrees +) cuts thru the atmosphere rapidly heating the air


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Tornadoes )ornadoes rapidly swirling funnel shaped cloud reaching

down from a cumulonimbus cloud to the ground. 2sually

occur in the 3reat !lains Tornado 4lley. ccur as a result of

+old dry !olar +ontinental 4ir 5ass collides w/ "arm

6umid Tropical 5aritime air mass off the +aribbean.


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Hurricanes Hurricanes a huge tropical c#clonethat has winds

in excess of 78 mph or higher. They are found in the 4tlantic, !acific and 9ndian

ceans. (in the western !acific they are called

typhoons) They begin over warm water areas as a low pressure

system or depression.


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Hurricanes


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Predicting t!e &eat!er Meteorologist a scientist who studies the causes of weather.

&eat!er Maps show: fronts, type of precipitation, hi low pressure areas, wind

speed and direction, cloud cover and temperature.

+so"arsThey are lines 0oining places on maps that have the same air pressure.

;arometric pressure is measured in -inches of 5ercury or -millibars.


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"hat type of precipitation will most liely follow if a humid

warm front over taes a cold front= $o what type of weather

will ensue a humid warm front=

9f warm air is humid, light rain or snow fall.

+,-T/ n'esti(ate an% earnin(

how to rea% weather maps

W th M


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Weather Maps Weather 2ap 6ymbols show types of precipitation, Wind speed,

wind direction, air pressure, fronts etc.

7ennants are 89 5nots.Therefore, the last wind example

in the chart below has a windspeed of :8 5nots. #89 5nots ;(9 5nots ; 8 5nots$.

3emember& Winds arenamed by stating thedirection from which thewind is coming. Thisdiagram indicates a (8

5not $ortheasternwind

Wind 6peed are given in 1autical2iles per hour

The white part of thecircle indicates whatfraction of the s5y iscloudy. e *8?


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'inal assessment for weather and the atmosphere(

)ro*ect+ Students will investigate their local weather for a

wee#. hey will record the high-low temperature, the

precipitation, the weather for the day, what the air pressure

was high or low(/0/1 mb is average anything above is

high pressure and anything below is low pressure2 .he

students will also record the humidity and conclude if high

or low humidity affect the precipitation for the day. %astly on

the final day they will ma#e a hypothesis based on the pastweather what the ne3t days weather will be li#e based on

what the 4th or 5th depending if they do 6 or 7 days of

recording.

Documents

Atmosphere and Weather-8th Grade- Revised