Air Masses

Differences in air pressure are caused by unequal heating of Earth’s surface – creates wind patterns – Deflects in a curved path because of the Coriolis effect Review

Along the surface, air moves from areas of high pressure to areas of low pressure – Poles to Equator At high altitudes, air moves from the equator to the poles

When air is stationary, or moves slowly, the air takes on the temperature and humidity of a region Target #9- I can describe how air masses form

Air Mass: a large body of air throughout which temperature and moisture content are similar Target #10- I can define air mass

Target #11- I can describe how air masses are classified Air masses are classified according to their source regions – Source region: determine temperature and humidity of an air mass Polar areas produce cold and dry air masses Tropical areas produce warm moist air masses

Continental: air masses that form over land – Form over large land masses – Low humidity – Brings dry weather – Continental Polar- cold and dry Symbol: cP – Continental tropical- warm and dry Symbol: cT Target #12 I can differentiate between continental and maritime air masses

Maritime: air masses that form over oceans – Form over large bodies of water – Higher humidity than continental air – Commonly bring precipitation when travelling over land – Maritime polar- moist and cold Symbol mP – Maritime tropical- moist and warm Symbol mT

Target #13- I can identify North American air masses on a map North American Air Masses – Continental Tropical Form in the southwestern U.S. Brings hot, dry weather – Maritime Tropical Form over the Atlantic Ocean Brings humid weather to eastern U.S. – Continental Polar Form in Canada Bring cool dry weather to northern U.S. – Maritime Polar Forms in northern Pacific & Atlantic Oceans Brings rain, snow, and fog to the Pacific Northwest and New England

New Jersey is about halfway between the equator and the North Pole – Geographic location results in highly variable daily weather Target #14- I can summarize how the air masses over New England influence New Jersey weather

The Garden State is 166 miles long, and is 65 miles at its widest point – There is a marked difference in climate between Wildwood and Ocean City in the south and High Point and Stokes State Forest in the north

The prevailing winds in NJ travel west to east – A part of the westerlies wind belt – Can shift north or south which influences the weather If shifting south, continental polar air brings colder temperatures with potential for snow If shifting north, maritime tropical air bring hot humid weather and potential for rain

Current Satellite Maps

In northern NJ: – Average annual precipitation: ~51in – Snowfall season: Oct to April – Precipitation comes from storms coming from the Mississippi Valley, Great Lakes, and from southern Canada. – The mountains also influence the formation of precipitation – The heat retained by the city also influences the types of weather produced

Analysis Question How do temperature and humidity change when a maritime tropical air mass is replaced by a continental polar air mass?