Download Unit Cheat Sheet- Part 1 Layers of the Atmosphere

Unit Cheat Sheet- Part 1
Layers of the Atmosphere
In order from the ground up…
Troposphere – all weather, clouds, hot air balloons, weather balloons here (temperature gets
colder as you go up in altitude)
Stratosphere- jets can fly here to avoid rough weather in troposphere; ozone layer at top
(protects us from harmful UV rays of the sun); temperature gets hotter the higher you go
Mesosphere- meteors burn up here & don’t hit Earth (Coldest layer)
Thermosphere (made up of Ionosphere & Exosphere)- hottest layer, Northern lights (Aurora
Borealis)
Ionosphere- radio waves, space shuttle
Exosphere- satellites; merges or blends with outer space as gets thinner
Atmosphere’s Purpose
Protect life on Earth (keep oxygen here for us to breathe, keep space trash from hitting Earth)
and regulate temperature on Earth so that it is livable.
How does it regulate temperature?
Atmospheric Heating
The sun sends rays of light and heat down to Earth everyday mainly through radiation. The
Earth’s atmosphere traps the heat like a blanket and keeps our temperature at a livable
degree.
How?
Heat is transferred through 3 processes…radiation, conduction & convection.
Radiation- heat transfer to an object when the object is near it or beside it (not touching it)
through electromagnetic waves. Example: sitting beside a fire and feeling the warmth, grilling
food, the sun giving you a sunburn at the beach
Conduction- touching the heat source or metal (metal is a great conductor of heat- it transfer
through it easily), plastic and wood are insulators that keep the heat in. Example: frying eggs on
the stove in a metal pan, touching a metal spoon that has been in hot coffee and it is warm to
the touch
Convection- like the convection currents in the mantle of Earth that the plates sit atop of and
move, warm air rises, cool air sinks, warm air is light weight, less dense, cold air is heavy and
more dense. Example: boiling water on the stove in a pot, steam leaving a cup of hot chocolate,
the upstairs in a home being warmer than the basement
What is the greenhouse effect? Our atmosphere traps heat for our temperature to be livable.
The greenhouse gases (carbon dioxide, methane, water vapor and more) trap the heat. This is
necessary for life on Earth. It would be too cold to live here without the greenhouse effect
occurring.
What can go wrong? Global warming?
When humans burn fossil fuels in cars (gasoline) or factories, and waste energy they create
pollution. That pollution rises into our atmosphere and pollutes our air. When the greenhouse
gases are not balanced (mainly when carbon dioxide is too high), the atmosphere traps too
much heat. The “blanket” is too thick and the Earth’s temperature gradually rises over time.
Negative Effects of Global Warming…
Higher than normal sea levels and temperatures
Increased number of hurricanes and intensity of hurricanes
Flooding
Melting glaciers and more…
Global vs. Local Winds
What causes wind? Differences in air pressure from one are to another and unequal heating of
the Earth by the Sun that creates temperature differences.
How do we get unequal heating on Earth?
The Earth is tilted 23.5 degrees and spinning toward the East, while revolving around the Sun.
The Sun’s rays hit the Earth at different angles with increased intensity (direct rays at the
equator-hot all year) or decreasing intensity (indirect rays at North & South poles- cold).
When density (how much air/liquid can be packed into a space) if high, air pressure is high,
temperature is low (cold)
When density if low, air pressure is low, temperature is high (hot)
Wind blows from cold toward hot
What is convection current?
The transfer of heat by circulation or movement of heated parts in a liquid or gas.
Warm air rises, cool air sinks
How does the Coriolis Effect influence wind patterns?
The Coriolis Effect is due to Earth’s rotation and causes things that would normally travel in a
straight path to curve. Winds in the northern hemisphere curve right and in the southern
hemisphere curve left.
Global Winds
Blow long distances, in predictable patterns, around the globe, bring weather our direction
1. Polar easterlies- cold, bring snow, near the poles
2. Westerlies- affect the US, below polar easterlies at the poles
3. Trade winds- located above and below the equator
Doldrums- area of little or no wind
Horse latitudes- area with weak winds, where deserts are located on Earth
Jet stream- strong, fast moving winds
Local Winds
Blow short distances, not in predictable patterns
Land breeze- cold air from the land at night blows toward the sea where it is warmer.
Sea breeze- winds blows from the colder sea during the day toward the land where it is
warmer. The high pressure is located over the sea.
Unit Cheat Sheet- Part 2
Humidity & Clouds
What is humidity?
Relative humidity is the amount of water vapor in the air that the air can hold (maximum it can
hold) at a certain temperature. It represents how close the air is to saturation (full).
Saturated air has an RH of 100%...rain is coming.
To measure relative humidity you use a sling psychometer.
The process in which water cools in the air and changes back into a liquid, condensing onto dust
particles is called condensation and this is how clouds form.
Review of clouds….nimbo means rain, cirro in front of the name means high altitude clouds,
alto in front of the cloud name means middle altitude clouds, and strato in front of the name
means low altitude clouds. The big storm clouds are called cumulonimbus.
The temperature at which water in the air (gas) turns into a liquid and condenses onto a surface
is the dew point. This usually happens at night. The grass is wet even when it doesn’t rain.
Air masses & fronts
What is an air mass? A large body of air where temperature (hot or cold) and moisture content
(dry or wet) are the same throughout.
Source region- the area where the air mass forms (example Gulf of Mexico)
Maritime (m)- forms over water, wet air mass (rain)
Continental (c)- forms over land, dry air mass
Tropical (T)- warm air mass; develops in the tropics
Polar (P)- cold air mass, develops in the polar regions (near North & South poles, Canada)
Air masses are written as follows…cT- the lower case letter is first and describes the moisture
content (wet or dry), the upper case letter comes next and describes the temperature (hot or
cold)
(mT) Maritime tropical air masses primarily affect us here in Georgia.
Fronts
The boundary between air masses of different densities and usually different temperatures.
When 2 air masses meet, warm air rises.
Cold front- cold air moves under warm air, which is less dense (less heavy) and pushes the
warm air up, move quickly, bring thunderstorms, followed by cooler, drier air
Warm front- warm air moves over cold air which is heavier, denser, the warm air gradually
replaces the cold air, bring drizzly rain followed by clear warm weather.
Occluded front- forms when a warm air mass is caught between two colder air masses, the
coldest air mass moves under and pushes up the warm air. Cooler temperatures, large amounts
of snow or rain.
Stationary front- forms when a cold air mass meets a warm air mass and neither has enough
force to push the other out of the way, so they stall out, and remain separated, pushing against
each other (like a tug of war battle), brings days of cloudy, wet weather.
Cyclone- an area in the atmosphere that has lower pressure than the surrounding areas and has
winds that spiral toward the center
Anticyclone- the rotation of air around a high pressure center in the opposite direction of the
Earth’s rotation
Severe Weather
Thunderstorms- a usually brief (short time), heavy storm that consists of rain, strong winds,
lightning and thunder (hail is possible)
Forms along cold fronts when warm, moist air near the Earth’s surface and the atmosphere is
unstable (air is colder than the rising air mass)- associated with large cumulonimbus clouds
Classified as a thunderstorm or severe thunderstorm (hail and tornadoes possible)
Lightning- an electric discharge that takes place between two oppositely charged surfaces
(positive & negative), such as between a cloud and the ground, between 2 clouds, or between
two parts of the same cloud
Thunder- the sound caused by rapid expansion of air along an electrical strike
Tornado- a destructive, rotating vertical column of air that has very high wind speeds, is visible
as a funnel shaped cloud and touches the ground (must touch the ground to be a tornado, just
a funnel cloud if it doesn’t), cumulonimbus clouds, updraft turns the column of air vertical,
measured on the Fujita scale (F0-F6 based on wind speeds ranging from 40-379 mph)
Very unpredictable paths, can jump and zig zag around, picks up debris and slings it (the most
deadly part of a tornado) Mainly occur in Tornado Alley- Oklahoma, Kansas, Missouri, Texas
Hurricane- a severe storm that develops over tropical (warm) oceans and whose strong winds
spiral in toward the intensely low pressure system storm center- center is called the eye, then
the eye wall surrounds it, and then rain bands feed out from there.

Most powerful due to size, wind speeds, time it spends on land, storm surge. Classified
in categories based on wind speeds from Category 1-70 mph and up to Category 5.
Saffir-Simpson Hurricane Scale
Storms surge- the large wall of water that a hurricane brings on land causes serious flooding
Severe Weather Safety1. Own a weather radio that is battery operated
2. Stay away from windows and doors during severe weather
3. Lightning strike the highest point (trees, poles), so stay away from trees and metal
objects
4. Evacuate for a hurricane to an inland location
5. Listen for tornado sirens and seek shelter in an interior closet or bathroom with no
windows with a mattress or pillows over your head.
6. Tornado watch- conditions are favorable for a tornado to form, be aware and listen for
further information
7. Tornado warning- a tornado has been spotted, seek shelter
8. Have a disaster supply kit read and on hand---water, canned food, medicines, important
papers, extra clothing, blankets, flashlight, first aid kit, whistle, batteries, phone charger,
can opener….etc
9. Have an evacuation plan in order…where will you go, have important phone numbers
hand, who will you call to keep in touch, gas up the car during hurricane season (mainly
summer months), board up the house (windows & doors), plan for pets
10. Pay attention to the news and weather daily