Air Masses and Weather

Objectives:

1. Identify factors that determine the characteristics of an air mass.

2. Compare and contrast different types of masses.

Key Terms:

meteorology air mass

Notes: (20-1)

Weather refers to the present state of the atmosphere & describes current conditions. It influences our lives and can change dramatically from day to day. The study of these changes is referred to as meteorology.

Weather Patterns:

Air masses – are large bodies of air in the lower troposphere that have the characteristics of the area where the are formed.

	Are responsible for daily change in the weather
	Create pressure systems
	Temperature and Humidity are dependant on the longitude and latitude of formation

(www.uwsp.edu/geo/faculty/ritter/ maps/air_masses_2.jpg)

Types of Air Masses

Continental Arctic (cA)

Air mass originates in the artic regions

Extremely cold and dry

Continental Polar (cP)

Air mass originates over Alaska and Canada (N.Hemisphere)

Mostly cold and dry with some precipitation

Maritime Polar (mP)

Air mass originates over the ocean in the high latitudes

slightly cold and moist

causes precipitation when they move on land (nor'easters)

Maritime Tropical (mT)

Air mass originates over the ocean in the mid latitudes

warm and moist

clockwise motion bring heat and moisture to the east coast and midwest

causes precipitation and thunderstorms as it moves on-land

Continental Tropical (cT)

Air mass originates over deserts in the mid and lower latitudes

hot & dry

can start out as mT that loses moisture it travels over a mountain range (rain shadow desert)

produces tremendous heat waves

(www.fernlea.com/graphics/ mapzone.jpg)

Last modified: April 07, 2003