Marking Period 4 Benchmark Study Guide
Chapter 5- Weather (pgs 118-136)
Weather is caused by the movement and interaction of air masses.
Air mass- a large body of air that has properties similar to the parts of the Earth’s surface
over which it develops. (page 126)
 Each air mass is described with a TEMPERATURE and MOISTURE (must
have 1 of each)
o Temperature
 Warm (tropical)
 Cold (polar)
o Moisture
 Moist (maritime)
 Dry (continental)
 EX: Air that forms over Gulf of Mexico would be Warm/Moist
Pressure Systems
 High Pressure System:
o High pressure does not allow air to rise & form clouds
o Gives fair/nice/”good/ sunny weather
 Hints: “HIGH 5”= GOOD
 HIGH (4 letters); GOOD (4 letters)
 Low Pressure System
o Low pressure allows warm air to rise, which forms clouds
o Creates cloudy, “bad” weather, usually with precipitation
 Hints: Low (3 letters); Bad (3 letters)
Fronts- a boundary that forms between 2 different air masses
 Usually CLOUDY & STORMY at a front boundary
 4 types of fronts: Cold Front, Warm Front, Stationary Front, Occluded Front
 Thunderstorms form along Cold Fronts; days of steady or gentle rain is associated
with Warm Fronts
 ***Review the pictures of fronts and the symbols used to represent them on a
weather map!!
Isobars- lines on a weather map that connect equal points of pressure.
 If the isobars are closer together that means stronger winds; farther apart the
isobars are the calmer the winds
Precipitation- water droplets falling to Earth (rain, snow, sleet, hail)
*****Be able to read a weather map!!!!!!
Chapter 4- Atmosphere
Air Pressure
 The higher you go up in the atmosphere the less dense the air is because there are
fewer air molecules
Heat Transfer
1) Conduction- heat transfer through direct contact
2) Convection- heat transfer through the flow of material
a. Cold material sinks because it is more dense; warm material rises because
it is less dense
3) Radiation- heat that travels in the form of RAYS or WAVES\
Gases in the Atmosphere
o Nitrogen (78%), Oxygen (21%), Other (1%)
Layers of the Atmosphere- know the characteristics of each layer
1) Troposphere- where we live, weather, air is highest in pressure here
2) Stratosphere- contain the ozone layer that protects us from UV Rays
3) Mesosphere- where meteoroids burn up
4) Thermosphere- hottest layer
a. Ionosphere- contains electrically charged particles
5) Exosphere-exits into outer space
Winds (are named from the direction where they come from)
 GLOBAL WINDS- (page 104-106)
o Doldrums
o East Trade Winds
o Prevailing Westerlies- moves weather across US
o Polar Easterlies
o Jet Stream
 LOCAL WINDS- (page 107) land cools & heats more quickly than land
o Sea Breeze
o Land Breeze
Water Cycle
 Precipitation
 Condensation
 Transpiration
 Evaporation
 Groundwater
 Runoff
2) Think Genetics!!!! Draw a Punnett Square and list 3 probabilities about the results.