Download What is an air mass?

Aim #30: How do air masses affect weather?
• Do Now: Answer the following questions in your
notebook (Write out in a complete sentence):
1. Earth’s weather is primarily caused by:
a. drifting of Earth’s crustal plates
b. Gravitational attraction of the moon
c. Uneven heating of Earth’s surface
d. Changing distance between Earth and
the sun
2. The movement of an air mass over Earth’s surface causes:
a. Earthquake activity
b. Local weather changes
c. Global warming
d. Ecological succession
Air
Mass
• Large body of air that has
same temp & amount of
moisture throughout
• Humid = form over water
• Dry = form over land
• Warm = form over warm areas
• Cold = form over cold areas
• Polar Air Mass = cold air mass
• 1. Continental polar = dry & cold
• 2. Maritime polar = cold & humid
• Tropical Air Mass = warm air
mass (forms over equator)
• 1. Continental tropical = warm &
dry
• 2. Maritime tropical = warm &
humid
*Do Now:
1) Take out Weather Log to be checked for HW grade
2) (Review) Create a table in your notebook to explain the 4
types of air masses. (Please include their symbols.)
Air Mass
Characteristics
Continental Polar
Maritime Polar
Continental Tropical
Maritime Tropical
H.W.
1) Weather Log- Monday
2) “What is an air mass” worksheet (handed out Thursday)
http://www.classzone.com/books/earth_science/terc/content/visualizations/es2001/es2001page01.cfm
Front • Region between air masses
• Changes in weather occur
here (usually precipitation)
• Types:
1. Cold Front =
• when cold air mass pushes into &
under warm air mass
http://www.stevemcentee.com/animation3.html
• Brief, heavy downpours, gusty
winds, cooler temperatures
2. Warm Front =
• when warm air mass
pushes over cooler air mass
http://www.stevemcentee.com/animation3.html
• Light precipitation, warmer
temperatures for a day or two
3. Stationary Front =
• when a cool & warm air mass stay
in one place for a while
http://www.stevemcentee.com/animation3.html
4. Occluded Front =
• a warm air
mass is caught
between two
cooler air
masses
http://www.stevemcentee.com/animation3.html
Aim #32: How can we compare
high and low pressure systems?
*Do Now: Use the venn diagram to compare and contrast a COLD
FRONT to a WARM FRONT.
COLD FRONT
WARM FRONT
H.W.
1)Weather Log- Tuesday
2) Measuring Up- pg. 220
*Do Now: Use the venn diagram to compare and
contrast a COLD FRONT to a WARM FRONT (you can
include stationary front to the similarities).
Cold front: A = cold air;
B = warm air. Here cold
air moves towards a
warm air mass and
forces the warm air to
rise.
Warm front: A = cold
air; B = warm air. Here
warm air moves towards
a mass of cold air and
rises.
http://www.classzone.com/books/earth_science/terc/content/visualizations/es2002/es2002page01.cfm?chapter_no=visualization
Aim #32(b): How can we compare
high and low pressure systems?
*Do Now:
Choose a city on
the weather map to
the right and
describe the
weather conditions.
H.W.
1)Weather Log- Wednesday
2) Using a weather map worksheet #s -
“How weather systems move from
place to place”- video
http://player.discoveryeducation.com/index.cfm?guidAssetId=639C
0D60-31EA-4C11-97E589DDF081A328&blnFromSearch=1&productcode=US
• “Highs” (anti-cyclones)
High
Pressure • Center of air masses
•
Clear
skies,
dry
weather,
System
gentle winds
• Air currents  move out
• Winds blow clockwise in
northern hemisphere
• “Lows” (cyclones)
Low
Pressure• Edges of air masses
•
Cloudy,
wet,
strong,
gusty
System
wind
• Air currents  move in
• Winds blow counterclockwise in
northern hemisphere
How can we remember the characteristics
of pressure systems?
Conclusion
Questions: