Download Factors Affecting Climate

CGC 1D
We live in a World of Systems
Factors Affecting Climate
There are six factors that affect climate in Canada.
“MALOOP”
M = Mountains
A = Altitude
L = Latitude
O = Ocean Currents
O = Open Bodies of Water
P = Pressure Systems & Winds
Mountains
1. Mountains block winds and create various climate effects. In Canada the
Western Cordillera mountain ranges block the moist, warm air from the
ocean getting to the prairies. They create relief (orographic) precipitation.
2. South facing slopes on mountains are warmer than north facing slopes
(micro-climates).
cooling, condensation & precipitation
rising air
South facing slope
Altitude
The height above sea level. The higher you go the colder it gets. Why?
1. The atmosphere is thinner with less gas molecules per volume. The
molecules are spread out and radiate less heat.
2. The higher you go the further you are from the heat radiating out from the
earth. For every 100 m up the temperature drops 1 ºC.
Latitude
The further from the equator, the colder it gets. For example: 45ºN, is colder
than 25ºN. 52ºS is colder than 45ºS. Why?
CGC 1D
We live in a World of Systems
Atmosphere
Earth
1. At latitudes further from the equator the sun’s rays coming in at a lower
angle and hit the surface of the earth and therefore have to cover a larger
area (so less intense heating).
2. Also, at higher latitudes, rays pass through a greater distance of
atmospheric gases. There is a greater chance of reflection and absorption
on their way to the earth.
Ocean Currents
The temperature of an ocean current affects the temperature of the air mass that
passes over it.
West Coast of Canada
 “North Pacific” Current (is warm)
 This current heats the cool moist air that passes over it
 This makes the climate of coastal B.C. very mild.
East Coast of Canada
 The cold “Labrador Current” (flows south from the Arctic)
 It cools the air above it (Nova Scotia and Newfoundland)
 The warm “Gulf Stream or North Atlantic drift” flows up the eastern NA
coast from Mexico.
 When these two air masses (Cold and Warm) meet off the coast of NS,
NL & NB the weather is damp and vision is impaired due to fog.
CGC 1D
We live in a World of Systems
Open Bodies of Water (unfrozen water)
Just being close to, or far away from, an open body of water will have an effect
on climate. Being close to an open body of water, keeps climate milder in the
winter and cooler in the summer.
The land heats up more quickly, and cools down more quickly than water. Any
winds blowing over the water will bring the warmth or coolness of the water on to
the shore.
Therefore: In summer, land will get a cooling effect from near-by water. In
winter, the land will get a warming effect. The further away from the water, the
less effect the water will have. This is called the moderating effect.
Results:
Maritime Climate: coastal areas have smaller temperature ranges (less than 25
Celcius degrees because winters are mild, summers are cool and mild), moderate
temperatures and more than 1000mm of precipitation per year. More
precipitation comes in the winter months.
Continental Climate: inland areas are a long way from the moderating effects of
the ocean. They have large temperature ranges (more than 25 Celcius
Degrees), extreme temperatures (very cold in winter, very hot in summer) and less than
1000mm of precipitation per year. More precipitation comes in the summer
months.
Pressure Systems and Winds
Air Masses:
 Are volumes of air with similar moisture content and similar temperatures.
 At any one level above the ground, the air mass will have the same
temperature
CGC 1D
We live in a World of Systems
Continental
Maritime
Polar
Maritime
Maritime
Air Mass
Continental
Tropical
Maritime
Conditions
Temperature
Continental
Arctic
cold & dry
Maritime
Polar
cold & humid 4C
Continental
Tropical
warm & humid 24C
Maritime
Tropical
cool & humid 24C

Air masses carry the characteristics of where they are formed:
o Over land – dryer
o Over water - moist
o Over equator – warm
o Over arctic – cold
 Different air masses don’t mix, where they meet is called a front.
 Cold air is heavy and dense, and so when it meets warm air, it pushes it
up (See cyclonic or frontal precipitation diagram)

Land heats up, warm air
rises, forms clouds and precipitation (short, strong storms over small area
– thunder storms) – Convectional precipitation

Warm air moving into cold area causes a warm front. Cold air moving
into an area of warm air causes a cold front.
o Cloud cover and rain over a larger area
o Usually Lighter rain when you have Frontal / Cyclonic precipitation
-40C
CGC 1D
We live in a World of Systems
Very Large, General Air Movements in the Lower Atmosphere:
Rising Air:
 This causes unstable conditions
 Causes a Low Pressure System
 Results in cloudy weather, rain or snow
Descending Air:
 Air going towards surface (descending) , creates a High Pressure
System
 Results in stable weather, clear, sunny skies
Winds:
The prevailing winds for most of Canada are called the westerlies
because they come from the west.
Fact: Winds will blow out of a high pressure area and blow into a low pressure
area.
H
L
The Polar Jet Stream
This is a very high altitude, very fast wind (300 to 500 km/h, 8000m to
14000m high)
 It flows west to east.
 It separates cold arctic air masses from the warmer, southern masses
 The Jet Stream is further south in winter, allowing cold air to go south into
the U.S.
 The opposite happens in summer.
 If your location is directly under the Jet Stream you will have unsettled
weather
CGC 1D
We live in a World of Systems
Air Masses of North America
(see page 81 in Textbook)
Winter Air Masses:
Which air mass affects Ottawa the most in January? Continental Arctic (N
and NW winds from the arctic)
Summer Air Masses:
Which air mass affects Ottawa the most in July? Atlantic Maritime
Tropical (SW winds from the USA)
Location of Polar Jet Stream:
Where is the Polar Jet Stream in relation to Ottawa in the winter? It is too
the south of us going over the middle of the USA.
Where is the Polar Jet Stream in relation to Ottawa in the Summer? It is to
the north of Ottawa over northern Ontario.
Temperature
(very cold, cold,
warm)
Tropical: warm
Polar: cold
Arctic: very cold
Name of Air Mass
Moisture Content
(wet or dry)
Maritime: wet
Continental: dry
Originates from?
Characteristics (moisture & temperature)