Unit 2: Climate

Question 1

What is the primary cause of Canada’s seasons

Answer 1

• earth’s tilt of 23.5 degrees

Question 2

what air masses affect canada in summer

Answer 2

• maritime tropical air masses
• responsible for the hot humid days of summer across central and eastern Canada
• warm humid and unstable

Question 3

what air masses affect canada in winter

Answer 3

• continental polar: cool and dry and stable, high pressure
• maritime polar (mP): cool and humid unstable (brings the snow)

Question 4

describe the changes a maritime polar air mass originating in the pacific will be modified as it moves from west to east

Answer 4

• starts in the west as unstable and humid (convectional lifting)
• then into the highlands of alberta, moisture removed (orographic lifting) leaving the east side of the rockies dry, semi arid through the prairies
• moving further, the now continental polar air mass will be more dry but still cold
• moving to manitoba and ontario the low pressure experience convergent lifting which caused higher precipitation (as well as lake effect)
• then reaching the Maritimes on the east coast the air mass would become unstable and humid maritime polar air mass once again

Question 5

what is orographic lifting

Answer 5

• when you have a physical presence of mountains as a barrier of the moving air masses
• the air is forced upslope and cools and condenses the moisture creating drier conditions on the leeward slope (rain shadow)

Question 6

compare precipitation for vancouver, calgary and winnipeg

Answer 6

• vancouver is very wet due to the unstable and humid air mass coming from the ocean, calgary is much drier because of the orogrpahic effect
• winnipeg has more precipitation due to the moisure being picked up from evaopration from lakes between the two cities

Question 7

what is chinook wind

Answer 7

• it is the warm westerly wind in western North America
• condensation releases latent heat.
• sinking air warms up
• happens in calgary
• as air moves up it expands and cools causing water vapor to rain our . the dry air then passes over the crest of the mountains and begins to move down the slope

Question 8

list and explain the three (four) main geographic factors affecting the temperature in canada

Answer 8

• latitude: daylength and sun angles change during the year increasing seasonal affect of increasing latitude
• altitude: density of atmosphere decreases with altitude, making insolation more intense at higher locations. at high elevation air temperatures are lower and night is colder
• cloud cover: clouds insulate preventing rapid energy loss and lower max and increase min temperatures
• land water heating differences: land and water store energy differently thus proximity to water would change the climate

Question 9

El nino and its affect of summer and winter

Answer 9

• warmer than normal winters for most of canada but often norther in the north
• drier than normal winters for much of southern canada
• drier west and south and wetter Maritimes

Question 10

what main factors makes canadas wind go from west to east (4)

Answer 10

• the coriolis effect: a force resulting from the earth’s rotation. winds move tot he right in the northern hemisphere
• jet streams: rossby waves that are developed at the axis of the jet streams and they go from west to east in NA
• pressure gradient force: unequal are creates unequal pressure and it flows from high to low pressure at increasing speed
• friction force: decreases win speed, reducing the coriolis force effect causes winds to move across isobars at an angle

Question 11

the arctic circle is a line of constant latitude, why

Answer 11

that the earth’s tilt does not change

Question 12

explain lake effect in the winter

Answer 12

• cold air from the old land to warmer lakes picks up moisture and loses stability and snows on the other side (east) and is slightly warmer

Question 13

where is freezing rain most likely

Answer 13

• ontario quebec and NB
• water particles falling as snow but then encountering a layer of warm air where the particles melt into rain and then that rain goes through a cold layer of air just before the surface of the ground until it makes contact with an object then freezes.
• the artic air mass is covering the area at this time but can have frontal lifting of warm air on top of cold air due to the low pressure in that area