Air Masses and Fronts Page 21 Air mass A. ____________- is a large body of air, in the troposphere, with similar characteristics of ___________, ___________ and ____________ B. Air Masses get these properties based on their _________ ________ Source Region= ______________________ __________________________ temperature moisture pressure Source Region the geographic area where an air mass forms

How Do Air Masses Form? Page 21 Air stagnates or sits over a particular region for a period of time, a week or two, acquiring the temperature and moisture of that surface Air masses have the same characteristics as their source region

The abbreviations used to classify air masses use the following letters: c, m, T, P, and A. For each letter, describe its property: Page 21 Word Means c m T P A continental dry maritime moist Tropical warm Polar cold Arctic very cold

Types of Air Masses Page 21 Dry & Cold cP continental Polar Symbol Name of air mass Characteristics Dry & Cold cP continental Polar Moist & Warm mT maritime Tropical Dry & Warm cT continental Tropical Moist & Cold mP maritime Polar cA continental Arctic Very cold, very dry

Use ESRT page 13 to label Diagram

What type of air mass would form over each area? Please label. cA mP cP cT mT mT mT Page 21

Page 13 Diagram- Check your Work

What would their characteristics be? mT cP warm and moist Cold and dry Page 21

High or Low Pressure? mT cP H L Page 21

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Review-Air Masses Page 21 Air Mass Classification Temperature due to Latitude: A for Arctic, P for Polar, T for Tropical; Moisture Content Identifiers: c for continental (meaning the air is relatively dry), m for maritime (meaning the air is relatively moist); Page 21

This map shows the air mass source regions and their paths

Source Regions &Air Masses Cold Front Video 0:14 Page 21

Ok, now we see the difference in the air masses Let’s look at the different fronts and their impact on weather Can you see the four different types of fronts on the map?

Questions Page 28 3 2 4 1

a boundary or interface Between 2 different air masses FRONTS a boundary or interface Between 2 different air masses Page 22

Use ESRT page 13 to label Diagram 21

Fronts _____________________________ A boundary _________________________ 4 Types of Fronts _______________ Weather Is usually occurring near a front Between 2 air masses cold warm stationary occluded Pg. 13 E.S.R.T.  Page 22

The Rule: triangles and bumps always point in the direction the front is moving Page 22

Cold Front- occurs when heavy cold air displaces lighter warm air, pushing it upward. Precipitation occurs ON a cold front Page 22

Cold Fronts Class Zone Animation #1 Page 22

Warm Front- occurs when warm air replaces cold air by sliding over it. Precipitation occurs AHEAD of a warm front. Front Page 22

Warm Fronts Page 22

Cold &Warm Fronts Video 2:26 Minutes Page 22

The Weather Highways The rotation of the earth creates the Coriolis effect. The Coriolis effect causes the air and water to be deflected to the right north of the equator. This creates global weather highways

The Westerlies Because of our latitude, most of our weather comes from the west Looking at the weather map, what type of weather might we expect? What type of weather might we expect in a few days?

Weather follows a pattern from West  East (NE) in the U.S.

Questions from Pages 23-24 3 1 2 4 1 3 4 2 4 3 1

Questions from Page 25