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

AirMass

•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 grade2) (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- Monday2)“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?

H.W. 1)Weather Log- Tuesday2) Measuring Up- pg. 220

*Do Now: Use the venn diagram to compare and contrast a COLD FRONT to a WARM FRONT. COLD FRONT WARM FRONT

*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 comparehigh and low pressure systems?

H.W. 1)Weather Log- Wednesday2) Using a weather map worksheet #s -

*Do Now:Choose a city on the weather map to the right and describe the weather conditions.

http://player.discoveryeducation.com/index.cfm?guidAssetId=639C0D60-31EA-4C11-97E5-89DDF081A328&blnFromSearch=1&productcode=US

“How weather systems move from place to place”- video

HighPressureSystem

•“Highs” (anti-cyclones)•Center of air masses•Clear skies, dry

weather, gentle winds

•Air currents move out•Winds blow clockwise in northern hemisphere

LowPressureSystem

•“Lows” (cyclones)•Edges of air masses•Cloudy, wet, strong,

gusty wind

•Air currents move in•Winds blow counterclockwise in northern hemisphere

How can we remember the characteristics of pressure systems?

Conclusion Questions: