Air Masses (Peso de Aire) and Weather (Tiempo)

Weather influences our lives every day. It helps us

determine:

• What we wear• Whether our airplane is delayed• Whether or not we go to school• What time to start football practice

Because of the weather’s influence, we need to know what the weather is going to be ahead

of time

Meteorology (meteorologia) – the study of the atmosphere and the factors that affect it

Changes in our weather are caused by the interaction of

air masses

An air mass (peso de aire) is a large body of air that has the same

temperature and humidity (humedad) throughout

Temperature and humidity depend on where the air mass originates

When an air mass enters an area, the area takes on the

characteristics of the air mass

When it gets hot and muggy in Topeka, it is because of an air mass from the Gulf of

Mexico

Types of Air Masses

Air masses are named according to where they were formed

The temperature of each air mass depends on where it was

formed

• Arctic (ártico) – forms above the Arctic Circle (A)

• Polar – forms over Alaska and Northern Canada (P)

• Tropical – forms close to the equator (T)

The humidity of an air mass depends on whether it formed

over land or water

• Continental – forms over land, dry (c)

• Maritime (marìtimo) – forms over an ocean, moist (m)

Continental Arctic (cA)

Characterized as very cold and very dry. These air masses produce cold weather, in winter but don’t occur in summer because the sun heats the poles

Continental polar (cP)

Warmer than cA air masses, but still cold and dry. These air masses can produce precipitation if they

pass over a large body of water

Continental Tropical (cT)

Characterized as hot and dry. These air masses produce heat waves in the summer

Maritime Polar (mP)

Characterized as cold and damp. These air masses produce heavy snows in winter and cool

temperatures in summer

Maritime Tropical (mT)

Characterized as warm and damp. These air masses produce thunderstorms