Chapter 16 Study Guide
16.1 Energy in the Atmosphere
Electromagnetic Waves
Radiation
Infrared Radiation
Visible light
UItraviolet Radiation
Scattering
Greenhouse effect
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Energy that can travel through space
Direct transfer of energy by EM waves
Invisible EM wave felt as heat
EM waves that our eyes can see (red = longer violet = shorter)
Invisible EM wave that can cause sunburn, mutation, or skin cancer
Light reflects in all directions – this is the reason the sky is blue (nitrogen
reflects blue wavelengths, absorbs red)
Natural process by which the earth retains heat
Know the 3 types of EM waves that enter the atmosphere (IR, visible light, UV)
Know what happens to them as they enter the atmosphere:
o Infrared – provides heat that is trapped near the earth and keeps the earth warm
o Visible Light – is scattered so that we can see
o Ultraviolet – mostly absorbed by ozone layer
o ****All are absorbed to some extent, or are reflected back into space***
16.2 – Heat Transfer
Thermal Energy
Temperature
Thermometer
Heat
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The TOTAL amount of energy of the molecules in a substance
The AVERAGE amount of energy in each molecule of a substance
A tool used to measure temperature
An energy transfer from a hotter substance to a cooler substance
Be able to describe how RADIATION, CONDUCTION, AND CONVECTION transfer heat in the atmosphere
o Radiation – Infrared energy in the atmosphere warms the earth’s surface, which warms the air touching
it
o Conduction – molecules of hot air touch each other (only happens near the Earth’s surface)
o Convection – Provides most of the heat in the atmosphere – hot air rises, cool air sinks. As the cool air is
heated it rises and is replaced by cool air. This forms currents in the air.
16.3 – Winds
Wind
Anemometer
Wind-chill factor
Local wind
Sea breeze
Land Breeze
Monsoon
Global winds
Coriolis Effect
Jet stream
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Horizontal movement of air from HIGH to LOW pressure areas
Tool used to measure wind speed – records in rpms  then converted to MPH
How cold the air temperature will feel outside due to the wind
Winds that are the result of uneven heating over a small area, usually where water
(lakes and oceans) meet land.
A local wind that blows from the water towards land during the daytime because the
air over the water is high pressure
A local wind that blows from the land towards the water at night because the air
over the land is higher pressure
Land and sea breezes over a very large area of Asia, responsible for dry and rainy
seasons
Winds that blow from very specific, unchanging areas over a large distance
The effect of the earth’s rotation on the way winds curve
High speed, high elevation winds that blow west to east that curve N and S.
Wind always moves from an area of HIGH pressure to an area of LOW pressure
Wind is always caused by pressure differences in the air – which is caused by heating of the earth by the sun.
Winds are named for the direction they blow FROM
o i.e. a wind from Canada towards the US would be a north wind
Anemometer – a tool used to measure wind speed.
Wind chill factor – the increased coolness felt by a wind.
o Only applies to living things!!!!! (can’t freeze water)
Show on a map winds blowing from high to low areas
Correctly name local winds (north, south, southwest, etc.)
Be able to label diagrams of sea and land breezes
o Which areas are high (H) and low pressure (L)
o Draw in arrows showing wind direction and temp (warm or cool)
Connect global winds to convection currents
Correctly draw curved arrows on a globe to show the coriolis effect
o Use this concept to understand Prevailing Westerlies and Polar Easterlies
o Westerlies – blow towards the poles from equator, earth’s rotation causes
Them to blow from west to east – affect US weather!!!
 Easterlies – blow towards equator, rotation causes them east to west. These collide with the westerlies,
causing major weather changes in the US
 Jet Stream – know what they are and approximately where they are on a map – how do we use them
(conserve fuel in west to east flight).
16.4 – Water in the Atmosphere
Evaporation (pg.545)
The process of liquid water becoming a gas (water vapor) due to heat.
Humidity (pg. 546)
Relative Humidity (pg. 546)
The amount of water vapor in the air
The RATIO of water vapor in the air to the total amount the air can hold.
Expressed as a percent (%)
A tool used to measure relative humidity
The process of water vapor cooling to a point that it bonds with other
particles and forms liquid water
The temperature at which water vapor in the air will condense. This
causes a frost if the dew point is below 32o F
Big, puffy clouds that indicate no rain. Low to the ground (< 2km).
Cumulonimbus clouds can be very tall (2 miles!) and indicate
thunderstorms
Long wavy, rolling clouds that indicate rain is coming. Nimbostratus
produce rain, drizzle, or snow
Clouds that form very high in the atmosphere. Look like wispy horse tails
or strings of cotton balls. Formed by small ice crystals due to cold
temperatures in upper troposphere
Psychrometer (pg. 546)
Condensation (pg.547)
Dew Point (pg. 547)
Cumulus (pg.548)
Stratus (pg. 548)
Cirrus (pg.548)
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Know that as the relative humidity increases, the lilkelihood of rain increases. Air must be at 100% humidity for
rain to form - but it can fall in areas of less than 100% humidity
Understand what relative humidity means and that air of different temperatures will have different relative
humidity (hot air holds more water vapor because it is less dense than cold air)
Understand how clouds form
Identify different cloud types: cumulus, stratus, and cirrus
o “nimbus” – rainclouds – nimbostratus and cumulonimbus
16.5 – Precipitation
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Know the 5 types of precipitation and how they form:
Rain:
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Rain is at least 1/2mm and falls quickly
Drizzle/Mist is less than ½ mm and falls slowly
Both require warm air (above freezing) and a warm surface (above freezing)to remain rain
Freezing Rain:
Sleet:
Hail:
Snow:
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Requires cold air (below freezing)
Forms ice crystals in clouds
Will accumulate only if ground is also below freezing
**Only HAIL and SNOW are solid states of water when they fall from the clouds – all other forms of precipitation start as
liquid water**