Continental + Maritime Environ. Why do Different Parts of Canada experience different climates? There are 4 factors that affect climate: Latitude Relief + Elevation Continental + Maritime Environ. Winds + Pressure Systems

Continental + Maritime Environ. Areas far from oceans and large lakes in the interior of landmasses have a CONTINENTAL climate These areas experience cold winters, warm to hot summers and experience less precipitation than areas located near water

INTERIOR CANADA

Continental + Maritime Environ. Areas located by the oceans (coastal areas) or lakes have a MARITIME climate. These areas experience cool to warm summers and experience larger amounts of precipitation than areas not located near water

COASTAL CANADA

Why is there a difference between these two areas?? 2 Reasons a) As an air mass passes over a large body of water (ocean or lake) it absorbs moisture. As the air continues on and passes over land the moisture may be released in some form of precipitation (rain/snow) Picks up moisture WET air mass DRY air mass LAND LAND LAKE

http://www.youtube.com/watch?v=_xMz2SnSWS4 RAIN RAIN RAIN! This is why areas located near water have a high amount of precipitation example – Vancouver or St. John’s Picks up moisture WET air mass DRY air mass LAND LAND LAKE

Why is there a difference between these two areas?? b) Water bodies moderate land temperatures Water gains and loses heat slower than land In the early summer, wind blowing off the water is cool, cooling the countryside (look at diagram)

Wind becomes cool over cool water Wind slowly becomes warmer Warm Land Cool Water In the early winter, wind blowing off the water is warm, warming the countryside (Diagram on next slide)

Wind becomes warm over warm water Wind slowly becomes colder Cold Land Warm Water Therefore a region near a body of water has winters not as cold and summers not as hot, compared to similar areas in the middle of a landmass (the temperature is MODERATED!)

Air Masses Affecting Canada

- = TR Temperature Range: Ie. 20°C – (-10°C) = 30°C - Subtraction of coldest average monthly temperature from warmest average monthly temperature - = TR Ie. 20°C – (-10°C) = 30°C

Continental Maritime - There is no body of water moderating the temperature

Ocean Currents The air mass passing over the current takes on the property of the current (hot, cold)

Air Mass: - A large volume of air with the climate conditions of the area where it formed

#5. - The air mass absorbs/picks up moisture from the ocean and will result in more precipitation in a maritime climate Air Mass picks up moisture WET air mass LAND LAND OCEAN

#6. - An air mass originating in a continental climate is dry as there is no moisture to absorb

#7. Continental - example? Typical Seasonal Temp: Annual Temp. Range: Annual Precipitation: HOT summers COLD winters >25°C <1000 mm

#7. Maritime - example? Typical Seasonal Temp: Annual Temp. Range: Annual Precipitation: COOL/WARM summers MILD/COOL winters <25°C >1000 mm

Winds and Pressure Systems Why do Different Parts of Canada experience different climates? There are 4 factors that affect climate: Latitude Relief + Elevation Continental & Maritime Environ. Winds and Pressure Systems

The last factor affecting climate is Winds and Pressure Systems The last factor affecting climate is Winds and Pressure Systems. Today we will focus on how winds are created and how our seasons are influenced by special forces such as the polar front and jet stream.

- Differences in air pressure are created when the earth is heated to different temperatures - Warmed air rising above the heated ground creates an area of low pressure - Cooled air falling towards the ground creates an area of high pressure

HOT L H Heated Ground - Air moves along the surface of the earth from high pressure areas to low pressure areas causing WIND

Prevailing Winds Polar Front http://en.wikipedia.org/wiki/Prevailing_winds - Winds that are most commonly found in Canada are the Westerlies which blow from West to East Polar Front - Stormy boundary between cold, dry polar air and warm, moist tropical air

Jet Stream: http://en.wikipedia.org/wiki/Jet_stream - High above the polar front is the jet stream that is moving from west to east at 300-390 km/hr, at altitudes between 9000-18,000m high - The polar front jet stream encircles the earth and changes speed in relation with

Summer - The boundary between cold and warm air moves northward, allowing warm air from the Gulf of Mexico to flow northward into Canada’s interior

Winter - The boundary between cold and warm air moves southward, allowing cold Arctic air to flow farther southward into the United States

http://www.youtube.com/watch?v=-K-z-mZ9Va4 When the warm air masses and cold air masses meet at the polar front, they do not mix easily which results in a battle in the sky (creating a storm)

Major Tornadoes in Canada Regina, Saskatchewan, June 30, 1912: 28 dead, hundreds inj. Edmonton, Alberta, July 31, 1987: 27 dead, 300 injured Windsor, Ontario, June 17, 1946: 17 dead Pine Lake, Alberta, July 14, 2000: 12 dead, 140 injured Valleyfield, Quebec, August 16, 1888: 9 dead, 14 injured Windsor, Ontario, April 3, 1974: 9 dead, 30 injured Barrie, Ontario, May 31, 1985: 8 dead, 155 injured Sudbury, Ontario, August 20, 1970: 6 dead, 200 injured St-Rose, Quebec, June 14, 1892: 6 dead, 26 injured Buctouche, N.B, August 6, 1879: 5 dead, 10 injured Major Tornadoes in Canada

Major Tornadoes in Canada Regina, Saskatchewan, June 30, 1912: 28 dead, hundreds inj. Edmonton, Alberta, July 31, 1987: 27 dead, 300 injured Windsor, Ontario, June 17, 1946: 17 dead Pine Lake, Alberta, July 14, 2000: 12 dead, 140 injured Valleyfield, Quebec, August 16, 1888: 9 dead, 14 injured Windsor, Ontario, April 3, 1974: 9 dead, 30 injured Barrie, Ontario, May 31, 1985: 8 dead, 155 injured Sudbury, Ontario, August 20, 1970: 6 dead, 200 injured St-Rose, Quebec, June 14, 1892: 6 dead, 26 injured Buctouche, N.B, August 6, 1879: 5 dead, 10 injured

http://www.youtube.com/watch?v=8apXOQQKuPU The Barrie Tornado: A Community rallies http://www.youtube.com/watch?v=8apXOQQKuPU

Major Hailstorms in Canada

http://www.youtube.com/watch?v=wZr8jXo1Uso&feature=related

Types of Precipitation

You will find it easier to understand why precipitation occurs, if you remember these 2 points: 1. error:/hy 2.

Air may rise for any of the following reasons: 1. It rises to cross an area of high elevation. This causes relief precipitation. 2. It rises because it has absorbed heat from the earth’s surface. This causes convectional precipitation. 3. It rises because there is cooler, denser air mass flowing beneath it that forces it up. This causes cyclonic precipitation.

1. Relief Precipitation Precipitation created when an air mass rises to cross a mountain barrier: Also called Orographic precipitation

WINDWARD LEEWARD Rainshadow Prevailing Wind 3. Air reaches the top, goes down other side (rain stops) WINDWARD LEEWARD 2. Air rises, cools, condensation occurs forming clouds (rain falls) Rainshadow 1. Warm moist air is forced up

2. Convectional Precipitation Precipitation caused by hot summer days, when heated land causes the air above it to rise by convection As the air rises, it cools and moisture condenses into clouds and precipitation. This type of  precipitation is common in the prairie province

2. Convectional Precipitation HOT SUMMER DAY Cumulonimbus cloud 2. Clouds form when the rising air becomes cool Convection level 3. Cooled H2O vapour changes into H2O droplets WARM AIR Vertical Updrafts WARM AIR PRAIRIES 1. Air close to the earth rises when heated by the sun (forms UPDRAFTS)

2. Convectional Precipitation HOT SUMMER DAY Cumulonimbus cloud 2. Clouds form when the rising air becomes cool Convection level 3. Cooled H2O vapour changes into H2O droplets WARM AIR 4. Creates thunderstorms with lightning (sometimes creates hail) Vertical Updrafts WARM AIR Downdrafts PRAIRIES 1. Air close to the earth rises when heated by the sun (forms UPDRAFTS)

3. Cyclonic Precipitation Precipitation caused when a warm, moist air mass is forced to rise by a cool, dry air mass This is also called frontal precipitation

3. Cyclonic Precipitation Heavier cool air forces lighter warm air up