Air Masses and Ocean Currents

Air Masses• Air Masses

– large volumes of air with similar temperature and humidity

- move due to changing pressure conditions

• Wind –the movement of air between these air masses

Four Types of Air Masses

Name Characteristics

Continental polar Cool and dry

Maritime polar Cool and moist

Continental tropical Warm and dry

Maritime tropical Warm and moist

When Air Masses Meet• Front – The leading edge of an

air mass or where two different air masses meet

- they cause sudden changes in weather such as a rise or fall in temperature and often precipitation

- In the Maritimes, most precipitation is caused when cold dry air from the north meets warm, moist air from the south

Ocean Currents• Ocean currents – the

movement of water in the world’s oceans

• Major currents influence climate

• Gulf Stream – an ocean current from the south which warms the South eastern Atlantic Provinces

• Labrador Current – a current that carries frigid water from the North to much of the Atlantic region

Fog• Fog – occurs

commonly here- When warm gulf

stream water meets cold labrador current water, the warm current cools. This causes moist air to condense into fog.