Transcript Climate Connections What is the difference between weather and

Climate Connections
What is the difference between weather and climate?
Weather is…
the day to day atmospheric
conditions
Describe our weather
characteristics:
- precipitation,
temperature, wind speed
and direction, humidex,
air pressure, UV index,
wind chill, visibility, cloud
cover, hourly forecast, 7
day forecast
Climate is…
long term pattern of
(weather) the day to
day atmospheric
conditions
Describe our climate
characteristics:
- cool winters, warm
summers
http://www.theweathern
etwork.com/weather/c
aon0512
How does weather affect How does climate affect
our lives in Ottawa?
our lives in Ottawa?
- prevent/cancel outdoor
- what we grow, where we
activities, deciding what
live, construction of
to wear day to day, snow
buildings (peaked roof,
storm may cancel
double-paned windows,
activities, will affect
furnace, insulation),
local driving conditions.
- what we wear over the
course of a year, fuel
costs, electrical costs,
winter/summer sports,
underground pathways
(winter city concept).
Four basic facts to remember when considering
Canada’s varied climate:
1. Canada extends a great distance from North to
South and East to West
- from Pelee Island in Lake Erie at 41̊ N to Alert at the northern tip of
Ellesmere Island at 83̊N for a distance of 4620 km north to south and
from Victoria to St John’s for a distance of 5260 km west to east.
2. Different elevations produce different climate
conditions.
- the higher the elevation the colder it can get.
3. Coastal regions have different climates from
inland regions.
- oceans and very large lakes, such as the Great Lakes have an effect on
climate.
4. Wind and pressure systems move weather
conditions from one part of the country to
another.
- the winds in Canada generally blow from the west, therefore most weather comes
from the west.
Six specific factors that effect climate:
Remember... LOWER near Water
Latitude
Ocean currents
Winds and Air Masses
Elevation
Relief
near Water
LATITUDE - distance from the equator...
Canada’s wide range in latitude has a major
impact on our climate.
Using the following three average annual
temperatures:
Pelee Island (41 N) 9.1̊C,
Yellowknife at -5.2̊C (62 N) and,
Alert -18.1̊C (82 N),
it is clear the locations closer to the North Pole
experience colder temperatures than those
nearer to the Equator.
Distance from the equator is a key factor (but not the only one) in
determining whether a region has a warm or cold climate:
Two factors are represented in the following diagram. Can you identify
them?
First: The sun’s energy
has to pass through
more atmosphere at
areas closer to the
poles because of the
curvature of the earth.
Second: The sun’s
energy is spread out
over a larger area
because of the
curvature of the earth.
The suns energy passes through more atmosphere.
Fig 13-2 page 146: Earth’s curvature causes the sun’s energy to be less
concentrated at the poles than near the equator.
Complete Weather and Climate 1 - Latitude
Ocean Currents:
Temperature of an ocean current affects
the temperature of the air mass that
passes over it.
What determines
whether an ocean
current is designated
a cold or warm current?
(See page 147)
Add your answer to your note.
http://www.youtube.com/watch?v=xusdWPuWAoU
East Coast: Cold Labrador Current which flow
south from the Arctic cools coastal locations in
Labrador and northern Newfoundland.
Gulf Stream, flowing north from southern
Atlantic warms coastal areas in Nova Scotia and
southern Newfoundland.
These two currents meet on the Grand Banks
creating damp and foggy conditions which
produces fog more than 100 days per year.
This is also an area of extreme marine
importance because of the large, valuable
fishing ground called the Grand Banks.
Oil is also being removed from several oil fields
below the ocean floor: White Rose, Terra Nova
and the largest, Hibernia.
Fig 13-3 Canada’s
weather and
climate are
affected by air
masses and ocean
currents
West Coast: Warm North Pacific current heats
the cold moist air which passes over it, giving a
mild climate to the coastal regions of BC.
The temperature rarely goes below 0 ̊C along the
coast of BC.
Wind and Air Masses - air masses will take on
the climatic conditions of the area where it was
formed and wind results from air moving along
the earth’s surface from an area of high
pressure to low pressure.
Air masses originating over the ocean contain a
considerable amount of moisture and as it
passes over land the moisture may be released
as precipitation.
Therefore, maritime locations receive more
precipitation then inland locations.
The opposite is true of air masses
originating over land, far from the
ocean. This air mass will be dry because
it lacks any source of moisture.
Complete Weather and Climate 2 - Air
Masses and Ocean Currents
Pressure Systems: - air has weight
Differences in air pressure are created
when the earth is heated to different
temperatures.
Remember:
Warm air raises creating an area of Low
Pressure.
Cool air falls toward the earth creating an
area of High Pressure
Wind
Wind
1. Heating of the ground by the sun warms
the air above it and causes the air to rise
producing a LOW PRESSURE.
2. The air cools and sinks producing a HIGH
PRESSURE
3. Air ground level moves along the surface
of the earth from a….
HIGH
LOW = WIND
Wind
Wind
Differences in Air Pressure
Average air pressure at sea level is 101.3 kPa
(kiloPascals)
Lowest ever recorded: 87 kPa in a Pacific Typhon
(hurricane)
Highest ever recorded: 108.4 kPa in Siberia
http://www.theweathernetwork.com/weather/caon0512
Today in Ottawa the air pressure is ______ kPa
Today’s weather is…
Complete Weather and Climate
3 - Differences in Air Pressure
4 - Highs and Lows
5- Cloud Formation
Prevailing winds are created by high and low pressure
belts around the earth.
In Canada, these come from generally from the west
and move the air masses which effect our weather.
The winds shift north or south with the season.
The degrees of latitude shown as the location of the pressure and
wind belts are yearly averages.
When you see the diagram below remember Canada is between 41̊N
and 83̊N.
Air rises high into the atmosphere at low pressure belts and
descends at high pressure belts.
The air then flows across Earth’s surface from high pressure belts
to low pressure belts creating prevailing winds.
Fig 13-4
Global pattern
of prevailing
winds.
Complete the handout Weather and
Climate 6 - Wind Belts
The boundary between cold, dry polar air
and warm moist tropical air is called the
polar front and high in the atmosphere
above the polar front is the jet stream.
Complete Weather and Climate 7 - Jet Stream
ELEVATION and RELIEF - differences in elevation of
the earth’s surface...
Mountain ranges act as barriers to the
movement of air masses.
The temperature drops steadily as you climb a
mountain at a rate of 6.4̊C for every 1000 m
which is called the environmental lapse rate.
Temperature decreases
with elevation
As air rises up the side of a mountain it expands
because of the lower air pressure.
As the air expands, it cools. When air is cooled,
it eventually reaches a temperature at which it
is saturated with water vapour.
Meaning, it is holding as much water as it possibly
can at that temperature and air pressure.
This is called the dew point and further cooling
leads to condensation.
Condensation is the change of water vapour into
liquid water.
This process will form clouds and if the droplets
grow large they may become rain, snow or hail
depending on the weather conditions.
Figure 16-6
Calculating
changes in
temperature
of a rising
air mass.
When condensation occurs, heat is given off. Cooling of the
air mass is still occurring, but since heat is being released
by condensation, the overall rate of cooling is less than
1C°/100m.
The rate of cooling when there is condensation can vary
somewhat: 0.6C°/100m is an average figure for this
cooling.
Complete Weather and Climate 8 - Temperature
Calculation Steps
Complete - Temperature Calculation I
- Temperature Calculation II
Quiz tomorrow, bring your own calculator
NEAR WATER
Areas located in the interior of large land masses, far
from oceans, and far from large lakes have a
continental climate.
The temperature range in these areas is great
because there is no large bodies of water to
moderate the hot temperatures of summer and
the cold temperatures of winter.
These areas have low amounts of precipitation.
Coastal locations (or near very large lakes) have a
maritime climate.
In a maritime climate, the range between the
highest and lowest average monthly
temperatures is relatively small because of the
moderating effect of the large body of water.
The level of precipitation is relatively high
compared to that of a continental climate
because of proximity of large bodies of water.
Areas near the Great Lakes are a special case,
while they are far enough from the oceans to
be continental, the lakes are large enough to
provide a partial maritime influence.
The climate here is sometimes call modified
continental.
Complete Weather and Climate 9 - Maritime and
Continental Climates
Oceans and lakes heat up and cool down more
slowly than land masses.
- this is because land is denser than water
therefore absorbs suns energy faster.
In winter (or at night), bodies of water
retain their heat and are warmer than
the land.
Winds blowing off the water keep the
surrounding countryside warm.
Land Breeze
In summer (or during the day), a body of water
remains cooler than the land surrounding it.
Winds blowing from over the water keep the
surrounding countryside cooler.
Water Breeze
Complete Weather and Climate 10 - Land and Water
Breezes
Precipitation:
To help you understand why precipitation
occurs remember these 2 points:
1. Air cools as it rises.
2. As air cools, water vapour condenses more
than it evaporates.
Air may rise for any of the following 3
reasons:
1. It rises to cross an area of high elevation.
This causes RELIEF precipitation (also known
as orographic precipitation).
This occurs in mountainous regions.
2. It rises because it has absorbed heat
from the earth’s surface.
This causes CONVECTIONAL precipitation.
This occurs mostly in the summer months.
3. It rises because there is a cooler, denser
air mass flowing beneath it that forces it
up.
This causes CYCLONIC precipitation (also
known as frontal precipitation). This
occurs year round.
Complete the handout “Relief Precipitation”