Download Air Pressure - earth science!

Name ____________________________
Study Guide for Weather and Climate Unit
______________________ is the condition of the atmosphere at a certain time and place. The
____________________________ is where our weather takes place.
___________________ is the average weather conditions in an area over a long period of time.
Unequal Heating
A. The source of all energy in our atmosphere that fuels Earth’s weather systems is
the __________.
B. _________________ – the heat energy that comes from the sun
1. Not all radiation reaches Earth’s surface.
a. Some energy is absorbed by the atmosphere.
b. Some energy is reflected back into ______________.
c. ____________ energy is ________________ by the Earth’s surface.
2. ___________________ _________________– when the amount of energy received from
the sun equals the amount of energy returned to space
3. There is _________________ heating of the surface of the Earth.
a. The main reason for unequal heating is the Earth is _________________, so not
all areas receive the same amount of radiation. The sun’s rays strike Earth
most __________________ at the ________________, but at an angle as you go north or
south. Therefore the equator is ________________ than the poles.
b. Another reason for unequal heating is that land heats and cools _____________
than water because land absorbs the radiation from the sun _____________ than
water.
Air Pressure
A. There is a column of air above you at all times. The measure of the force with
which air molecules push on a surface is _________ ________________, also called
atmospheric pressure.
C. There are 4 factors that influence the air pressure in an area:
1. ___________________ 2. ____________________ 3. ___________ __________ 4. __________________
1. Elevation: Air at ________ ___________ has more molecules in each cubic meter
of space than air at the top of a mountain. The density of air _______________
as altitude increases. Atmospheric pressure is _________________ near Earth’s
surface and _________________ as you move upward away from sea level.
2. Temperature: The ______________ the air, the more the molecules move
_______________ one another. Colder air is _________ dense. More dense air
pushes _________ and has a _____________ air pressure than warm air. The
______________ the air, the more the molecules move _____________. Warmer air
is _________ dense. Less dense air __________ upward and has ___________ air
pressure than colder air.
3. Water Vapor: More water vapor in air has less ________ ________________
because part of the space is being taken up by water; therefore there are
___________ air molecules per cubic meter of space available to push down. The
most important function of the _____________ is giving off water ___________ into
the atmosphere.
4. Location: Air closer to the poles is _____________ and __________ dense than air
near the equator. Therefore there is ____________ pressure near the poles than
at the equator. Places that have similar ________________ (distance from equator)
most likely have similar climates. Air moves in large, circular patterns called
______________________ __________.
Wind
A. Differences in air pressure cause ________. Winds
occur because air tends to move from regions of
_____________ air pressure to regions of ________ air
pressure.
1. As warm air becomes less dense it
___________. (low pressure)
2. The colder, ________ dense air pushes
down (high pressure) and rushes in to take the
rising, warm air’s place.
3. Winds are named from where they
_________________ or came from.
B. Local winds – _________________ winds that blow in an
area and are produced by temperature differences
caused by local _____________________ _________________
Ex: Sea and Land breezes
1. Sea Breezes –
a. Land heats up during the ________
b. Air over __________ gets warmer than air
Draw a sea breeze here:
Sea
Land
over water
c. ________ air over land __________, while cooler, more dense air from over
____________ rushes in to take its place
2. Land Breeze
a. Land cools down at ___________
b. Air over _________ gets cooler than air
over ___________
c. _____________ air over ocean ________ while
cooler, _______ dense air from over ________rushes in to take
its place (Example: Before sunrise on the beach, air over
water is _____________ than air over land.)
Draw a land breeze here:
Sea
Land
C. Global Winds – blow almost ___________________ in ____________ direction
1. Air above the poles is very ______ (higher density and higher pressure)
2. Air above the equator is ______________ (less density and lower pressure)
3. The lower pressure warm air ________ and the higher pressure cold air ______
and rushes toward the lower pressure areas (equator).
4. The rising, low pressure air at the equator is pushed toward the _________
creating global winds
5. Coriolis Effect – the _______________of the Earth causes the wind paths to
_________ to the left or right.
D. ________ _______________ - fast moving, narrow belt of wind that has a great impact on
changing weather conditions because it determines major air movements.
Air Masses
________ ____________ - large body of air that gets its temperature and humidity ________ the
_________ or ___________ over which it forms
Warm
Wet
Maritime tropical
Dry
Continental tropical
Cold
Maritime polar
Continental polar
The cause of changes in the weather is when air masses __________ and __________.
Fronts
___________ - boundary between 2 different air masses; Fronts usually bring some type of
_______________________.
a. _________ front – ______________ moving cold air overtakes the slower moving ________
air; The warm air quickly ___________ allowing water vapor to ________________.
Thunderstorms and ______________ weather are common at these fronts. (Draw a picture
of a cold front here.)
On a weather map a cold front is represented by __________ __________________.
b. ________ front - warmer air slowly moves _______ colder air and replaces it; Leads to
long periods of steady _________ or __________. (Draw a picture of a warm front here.)
On a weather map a warm front is represented by _______ ______________________.
c. ________________ front - a ________ front and a ________ front meet, and neither can
_________the other out of the way; creates days and days of the same weather (rain or
dry spells).
(Draw a picture of a stationary front here.)
On a weather map a stationary front is represented by __________________ red semi-circles
and blue arrows pointing in __________________ directions.
d. __________________ front – a warm air mass is ________________ between a _________air mass
and a ________ air mass. The warm air is _____ ______from the surface. This leads to
_________ _________. (Draw an occluded front here.)
On a weather map, an occluded front is represented by ____________ semi- circles and
arrows pointing in the __________direction.
Pressure Systems
a. Low Pressure Systems
1) Winds blow _________ low pressure areas
2) ___________, __________ air will rise, causing _________ formation
3) Weather is usually _____________ or _____________. Cloudy nights can be
______________ than clear nights because clouds trap heat _______________ by
Earth during the daylight hours.
b. High Pressure Systems
1) Winds blow _________ from high pressure areas
2) ______________ motion of air makes it ______________ for clouds to form
3) Weather is usually _________ and __________.
Severe Weather
1. _________________________ are brought by ______________________ clouds.
2. _________________ are violent, whirling winds that form over __________.
3. _________________ are large, swirling storms that form over the ____________. They are
the ___________ powerful storms. ________, _________ air must be present for a hurricane
to develop.
Resources
 ___________________ is an example of a _____________________ resource.
 _______________ is an example of a ________________ resource/alternative to fossil fuels.
 Alternative fuels are important because fossil fuels are ________ renewable, and we
need other choices for energy.