1 lesson 02: weather and climate section 4.10 pages 220-221
TRANSCRIPT
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Lesson 02: Weather and Climate
Section 4.10
Pages 220-221
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Difference between weather and climate.
Weather describes what is happening outdoors when you look out the window.
Weather is the atmospheric conditions that happens from minute to minute.
The weather can change a lot within a very short time. For example, it may rain for an hour and then become sunny and clear.
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Difference between weather and climate.
Weather is what you hear about on the television news every night.
Weather includes daily changes in precipitation, barometric pressure, temperature, and wind conditions for your area.
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Difference between weather and climate.
Climate is the expected weather conditions for your area during different times of the year.
Climate is based on 30 year average. Includes average weather conditions,
regular weather patterns (like winter, spring, summer, and fall), and special weather events (like tornadoes and floods).
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Difference between weather and climate.
Climate data includes information such as:
1. Precipitation 2. Temperature
3. Humidity, 4. Sunshine
5. Wind velocity 6. Wind direction
7. Fog 8. Frost
9. Other distinct conditions
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Factors Affecting Climate:
1. Latitude
2. Ocean currents
3. Wind and air masses
4. Elevation
5. Relief
6. Closeness to water.
7. Human activities
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Factors Affecting Climate: Latitude
Latitude measures the distance north or south from the equator.
The equator receives more sunlight than anywhere else on earth.
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Factors Affecting Climate
The equator is hotter because the sunrays are more direct.
The sun rays hit the earth at an angle as you move away from equator causing the energy to spread out.
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Factors Affecting Climate: Ocean Currents
Ocean currents can greatly affect temperatures and weather conditions.
Two types: Cold Ocean currents and Warm Ocean currents.
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Factors Affecting Climate: Ocean Currents
Example: Two main ocean currents affect
Newfoundland and Labrador: the Gulf stream and the Labrador Current.
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Factors Affecting Climate: Ocean Currents
The Gulf Stream is a warm ocean current in the North Atlantic flowing from the Gulf of Mexico, and across the southern part of Newfoundland.
The air above the gulf stream is warm and moist.
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Factors Affecting Climate: Ocean Currents
The Labrador Current is a cold ocean current that starts up in the artic ocean travels south along the coast of Labrador colliding and mixing with the Gulf stream in the Grand Banks.
The air above the Labrador current is cold and
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Factors Affecting Climate : Ocean Currents
What will happen when the warm moist air of the Gulf stream passes over the cold water of the Labrador Current?
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Factors Affecting Climate: Ocean Currents
The west coast of Canada is influenced by the warm Alaska current which starts in the warm south Pacific ocean and moves up the west coast north towards Alaska.
The result is that British Columbia has warm, mild winters. This is why coastal British Columbia gets very little snow in the winter.
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Factors Affecting Climate: Ocean Currents
Interesting Note: Oslo Norway has ice free ports all year
round but is further north than Goose Bay, Newfoundland! During the winter Goose Bay is frozen up solid!
This is due to the fact that Norway is under the influence of the warm Gulf Stream where as Goose Bay is under the influence of the cold Labrador Current.
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Factors Affecting Climate: Wind and air masses
Winds that blow from the sea often bring rain to the coast. As an air mass moves over water the air picks up moisture.
Newfoundland and Labrador's weather is influenced by maritime air that is generally quite cool and moist.
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Factors Affecting Climate: Wind and air masses
The winds blowing over the cold ocean water in summer tends to cool the summer air.
During the winter the oceans are generally warmer than the winds so the winter air becomes mild and wet as it blows over the ocean.
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Factors Affecting Climate: Elevation
Elevation measures how high you are above sea level. As you rise the air cools, in fact the air cools by 6.5oC for every kilometer (1000m) you rise.
The higher the elevation, the colder it will be. This happens because as altitude increases, air becomes thinner and is less able to absorb and hold heat.
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Factors Affecting Climate: Elevation
Gros Morne Mountain is 807 m above sea level. If the air temperature on the bottom is 20oC expect the temperature to drop as you hike to the top. When you get to the top it will only be about 15oC - take your jacket!
Mt. Logan in the Yukon is Canada's highest Mountain at an elevation of 5959 m. 20o C at
the base quickly changes to -18oC at the summit! Brrr...!
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Factors Affecting Climate: Relief
Climate can be affected by large mountains.
Mountains receive more rainfall than low lying areas because the temperature on top of mountains is lower than the temperature at sea level due to the elevation.
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Factors Affecting Climate: Relief
So the amount of precipitation and the temperature depends which way the wind is blowing and what side of the mountain you are on!
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Factors Affecting Climate: Closeness to water.
Coastal areas are cooler and wetter than inland areas since wind blowing over the water picks up moisture and is cooled by the body of water.
As the cool air pushes inland and collides with cool sea breeze clouds and maybe rain will form
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Factors Affecting Climate: Closeness to water.
In Newfoundland you may have noticed that inland communities like Gander and Grand Falls have much warmer summer time temperatures than areas out around the coast.
In winter time the coastal air is warmed by the ocean so the coastal areas have slightly warmer winter temperatures than central areas.
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Factors Affecting Climate: Human Activities
Human activities are now beginning to influence local climates as well as the global climate.
Southern Ontario (places like Toronto) now includes smog as part of the climate data for spring and summer. The excessive pollution from cars and industry, high temperatures and high humidity combine to produce an unhealthy atmosphere.
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Factors Affecting Climate: Human Activities
The burning of fossil fuels in cars, industry and home heating causes global climate change.
Global warming may be responsible for variations in climates and increased amounts of severe weather in the world.