Air Masses

Phenomenon

Rainfall and temperature patterns that make up climate are affected by movement of air masses. Why?

Air masses are large regional volumes of air of similar temperature. Air masses are important for weather forecasting since the air mass characteristics of temperature and moisture content can be used in predicting the probability of rain, snow, or dry weather.

Air masses also influence climates. Air masses are classified by water content and temperature. Climate types are also classified by precipitation and temperature. Prevailing winds and air masses are connected concepts that are useful in explaining the climate of a location.

Explaining Patterns

Use the map, table, and your knowledge of knowledge of properties of land and water to answer the following questions.

What patterns do you notice relative to latitude?
Why are maritime air masses wet?
Why are continental air masses dry?
Why are polar air masses cold?
Why are tropical air masses warm?
Why are Arctic and Antarctic air masses continental, but not maritime?

Latitude Connections

In the midlatitudes, there may be be seasonal variations in air mass influences that are associated with the climate of a region. For example, New Jersey is affected by maritime tropical air masses most of the year, but a strong maritime polar air mass can bring heavy snow or rain in the form of a nor'easter. The influence of the continental polar air mass is felt most strongly in New Jersey during the winter. On rare occasions, an arctic air mass may dip into northern New Jersey bringing frigid winter conditions.
Air masses tend to move with the prevailing winds.