Download Notes 14 – Air Masses and Fronts

Notes 5 – Meteorology
Mrs. Gordon
Earth Science
Friday, February 06, 2015
What is meteorology?
 1. Meteorology –
the study of
weather
– A. Weather – short
term conditions
– B. Climate – long
term averages
2. Weather where we live:
 In the Northern Hemisphere:
 A. Low pressure systems rotate COUNTER
clockwise with RISING air. (less dense, warm air)
 B. High pressure systems rotate CLOCKWISE with
SINKING air. (dense, cool air)
Will you ‘front’ me some $$?
 3. Front – the boundary between two air
masses
 A. Warm Front - warm air meets cold air,
is pushed up and COOLS and
CONDENSES (clouds)
• B. Cold front – when cold, dense air
meets warm air, it slides under, and
forces the warm air to rise
As warm, moist air rises, it COOLS and CONDENSES =
cloudy weather
4. Rain Shadows
 Air rises, cools and condenses = rain on the windward
side of mountains.
 Air mass moves over mountains and is now dry
 ‘Rain shadows’ or dry environments on leeward side.
 Farther from the ocean = less yearly rain fall.
What is an air mass?
 Air Mass - A huge body of air that has
similar temperature, moisture and
pressure. (check your definitions on previous page)
Types of Air Masses:
 Maritime Polar (mP)– cold, moist,
forms over oceans, high pressure
 Continental Polar (cP) – cold, dry,
forms over land, high pressure
(Check your
definitions on
the previous
page)
Types con’t……
 Maritime Tropical
(mT) – warm, moist
(humid), forms
over oceans, low
pressure
 Continental
Tropical (cT)–
warm, dry, forms
over land, low
pressure
(Check your
definitions on
the previous
page)