Download Climate Control

Geography 12
Weather and Climate
Big Idea: What creates the
climate of an area?
We will do some work on climate controls,
discuss weather, and then return to climate
zones of the world
Here is what you will learn today:
• Climate is what you can expect the weather to be like
over a long period of time
• There are several things that determine what the climate
will be:
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How far is the place from the equator?
What season is it – is the area tilted away from the sun?
Are there warm or cold ocean currents nearby?
What is the altitude (metres above sea level)?
Is it on or near a large body of water, like the ocean?
Connected to this is – is it inland (continental or maritime)
What are the prevailing winds in the area?
WALMPOC
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Water
Altitude
Latitude
Mountain Barriers
Prevailing winds
Ocean Currents
Contintentality
• Another way to
remember this is to
use the mnemonic,
WALMPOC
Let’s go over them
one by one
Idea to understand:
What is the difference between
weather and climate?
Weather
Weather tells you
what to wear on a
daily basis
• Weather is day-to-day
• What is happening at
any moment
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Sun
Rain
Wind
Snow
Fog
cloud
Will I need
my toque
today?
http://www.bluenose2.ns.ca/Catalogue/Clothing/
OhCanadaLongToque.html
Climate
• Climate is what is
normally expected in a
place year after year
http://www.circlearanchhostel.com/recgal.html
http://www.brazadv.com/brazil_tours/montane_rainforest.htm
• What weather would you
expect day after day in
these two places and
why?
Climate and Seasons
• In the pictures on the previous slide, we looked
at two places where the weather is the same all
year long – the desert, and the rainforest. Very
little changes, month to month
• In other places, like Fort St. James, we have a
climate that changes with every season
• Think about why we have seasons, while other
places do not… more on this in a moment
• What is interesting about all this is that there are
many different things that impact what the
climate is in a place
Idea: The difference between
climate and weather
What kinds of questions would we ask?
• Climate!
– How much precipitation do
we usually get in a year –
can we farm here?
– How should we build this
house – does it need a
strong roof to carry a lot of
snow?
– Are there four seasons
(spring, summer, winter
and fall?) in this area?
– Can our town have a ski
hill?
• Weather!
– What should I wear today?
– What will the roads be like
today or tomorrow?
– Is it going to rain when we
go camping this weekend?
– Do I need to wear my coat?
The world has several climate zones or
areas.
http://en.wikibooks.org/wiki/Basic_Geography/Climate/Global_Climate
Why are there different climates in
different parts of the world?
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Water
Altitude
Latitude
Mountain Barriers
Prevailing winds
Ocean Currents
Contintentality
Climate Control: Latitude
Look at this globe
•
You can see that the earth is titled
a bit on its side (on its axis – which
is an imaginary line through the
middle of the planet)
The Earth’s tilt on its axis
• You can see that the northern part of the
world - where we live - spends LONG
HOURS in the sun (summer), but only
gets a VERY FEW hours once it is tipped
away from the sun (winter)
• Notice that the equator gets about 12
hours of sun ALL YEAR ROUND, so they
don’t have seasons like ours
Where on Earth are we?
We live way up
here, far north of
the equator. We
have long days in
the summer and
short days in the
winter. We have
four very distinct
seasons because
of our latitude.
http://www.jupiterimages.com/itemDetail.aspx?itemID=23501499
This is the
equator – no
real seasons
in most areas:
12 hours of
daylight all
year.
Length of time a place is exposed
to the sun
• The north and south
of the planet are
exposed the sun for
fewer months of the
year
• The less sun, the
colder it is
Climate Control: Latitude
Less time in the sun, but also, less strength in the
sun
Equator
Key term: Insolation: amount of
sun received at the earth’s surface
•There is another important
idea about latitude as a
control
•Because the earth is round,
and titled, the sun’s rays hit
the earth at different angles
•So, you can see that at the
equator, the sun comes
straight in and heats the
area more strongly
•North and south of the
equator, the rays are spread
out and less strong
Here’s another picture to show how
important the idea of latitude is to
climate
• See that the same
amount of sun is
coming in, but the sun
is much more
concentrated or
strong in the first
example
• MUCH WARMER!!
Climate Control: Altitude
• Altitude – how high
above sea level the
land is
• This mountain is
located in the Alps
• Why is there snow
here…
• But not here?
Answer: Usually, air cools as it rises
• The higher the mountain, the cooler the temperature at the top
• In general, for every 150 metres of rise in altitude, the
temperature drops 1 degree Celsius – the air becomes thinner
and less able to hold onto heat
• Sometimes, an inversion occurs and it is warmer on the
mountain than in the valley – like happens at our ski hill once in
a while
•
http://staffwww.fullcoll.edu/tmorris/elements_of_ecology/chapter_3.htm
Glaciers at the equator?
• This is a picture of a glacier
located on Mount Kenya, in
Kenya Africa
• It is located just south of
the equator
• Why is it a surprise to find a
glacier at the equator?
• What does it tell you about
how altitude can change
the climate of an area?
• The glaciers on this
mountain are disappearing.
What would cause this?
Climate Control: Ocean Currents
• Think about the idea that some ocean currents
are warm and some are cold. What climate
would you expect on a coast with warm water?
What climate would you expect with cold water
currents?
Here’s another look
http://scripts.mit.edu/~gmaze/blog/
Where are most of the cold currents? Where are most of the warm currents?
Why do you think it is this way?
This is a cool way to look at ocean
currents
http://blue.utb.edu/paullgj/geog3333/lectures/physgeog.html
Use what you know:
http://scripts.mit.edu/~gmaze/blog/
• Based on the information on this map and on the
animation you watched, why is London, England a
warmer place to live than St. John’s
Newfoundland, Canada?
Climate Control: Distance from the
Sea aka Continentality
• The climate of an area will be different if it is
located beside the ocean, or inland, away from
any large body of water
• Think about what you know about the climate in
Vancouver. What is it like there?
• Think about what you know about the weather
here in Fort St. James, which is pretty far from
the ocean. How are they different?
• Key Terms: maritime climate and continental
climate
Climate Control: How close to the
ocean?
• Places that are near water usually have a
lot more rain or snow than places inland –
especially if the ocean current is warm
• The warm moist air blows in off the ocean
and drops its moisture on the land in the
form of rain and snow
The climate of places on the ocean
are usually milder than inland
• Mild means not that hot, and not that cold!
• Places like Vancouver or Victoria that are on or
near water, will be WARMER in winter (NOT AS
COLD), and COLDER(NOT AS HOT) in
summer.
• Hmmmmm????
• Why is that? Take a look at the next slide
There are two ideas here that are
important!
• Water takes a long time to warm
up, but water cools down very
slowly
• Land warms up quickly, and also
land cools quickly
Summer
The ocean
heats up
slowly, so
summer
temperatures
on the ocean
are much
cooler during
the summer,
as cool
ocean wind
blows in.
North America
The land
heats up
fast, so
summer
temperatures
away from
the ocean
are hot,
HOT!
Winter
The ocean
cools down
very slowly,
so the air
over it is
warm, and
this warm air
blows into
the colder
land,
keeping
coastal
areas
warmer in
winter.
The land
cools down
quickly, so
winter
temperatures
inland are
COLD!
North America
Use what you know:
• Why would it be very
hot in the Prairies
(Alberta,
Saskatchewan) in the
summer?
Climate Control: Prevailing
Winds
• Air pressure and winds (caused by air pressure)
• Winds off a warm ocean will bring rain
• Winds coming from the Arctic will be dry and
cold
• Prevailing means the winds you can expect over
the long term, so they can impact the kind of
climate you expect in a certain place
• Prevailing
winds of the
earth
Climate Control: Mountain
Barriers
• impede the
• Mountains can also
movement of cold air
result in warm winds
masses. This is due
descending down
to the fact that cold air
slope
is dense and
generally stays near
to the ground.
• Vancouver is shielded from most Arctic air
masses by the Rockies and Coast Mountains.
• a chinook: a warm wind that undergoes
adiabatic heating. This westerly wind is dry and
blows down the eastern side of the Rockies
affecting cities such as Calgary.
Use what you know:
• Why would it be
raining in Vancouver?
• And dry and windy in
Calgary?
To sum up, or review:
• Climate is what you can expect the weather to
be like over a long period of time
• There are several things that determine what the
climate will be:
– How far is the place from the equator?
– What season is it – is the area tilted away from the
sun?
– Are there warm or cold ocean currents nearby?
– What is the altitude (metres above sea level)?
– Is it on or near a large body of water, like the ocean?
– What are the prevailing winds?