CLIMATE

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CLIMATE
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Day vs. Night

• Earth rotates on its axis (24 hours).
• Results in day and night

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Seasons

• Earth revolves around the Sun (orbits 365 days).
• Results in seasons

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Cloud Cover

• Cloud Cover
• Nightly cloud cover will result in less
  temperature range (like a blanket)
• Without cloud cover, heat escapes (at night), but
  temperature range is very high (hot days, cold
  nightsthe desert)

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Differences in Day Length

• The tilt of the earths axis combined with the
  earths rotation in orbit around the sun results
  in different day lengths. The difference?
• In June because of the tilt on the earth's axis,
  the north pole points towards the sun and
  receives more hours of exposure to the sun hence
  giving it longer days.
• In December because of the tilt on the earth's
  axis, the north pole points away from the sun and
  receives fewer hours of exposure to the sun hence
  giving it shorter days.

SUN
JUNE
DECEMBER
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SEASONS

• The tilt on the earth's axis and
• The revolution of the earth around the sun
• These two features of the earth-sun relationship
  mean that different latitudes on earth receive
  different directness of light at different times.
  

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Equinox and Solstice

• Solstice
• sun is directly over head _at_ 12 noon on 23.5º
  North or South
• occurs Dec 21 June 21
• longest day of the year shortest day of the
  year.
• Equinox
• sun is directly over head _at_ 12 noon on the
  equator
• occurs Sept. 21 March 21
• equal length of night and day everywhere on
  earth.

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Tropics vs. The Poles

• The tropics are located between 23.5 north and
  23.5 south(Cancer and Capricorn)
• The further you move away from the tropics the
  more severe the seasons.
• The length of day varies more the further you
  move from the equator.
• When light hits the earth towards the poles it is
  on a severe angle which decreases the intensity
  of heat.

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How the Sun hits the Earth
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Greenhouse Effect

• A good thing?
• In moderation of course moderates our
  temperatures
• Without we would have extreme variation of
  temperatures between day and night
• Atmosphere reflects and absorbs about 50 of
  radiant energy
• Without atmosphere, planets have nothing to hold
  heat in (like the glass in a greenhouse
  consequently the nights are not as cool)

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Latitude and Temperature

• The closer we get to the equator, the warmer it
  gets
• The further south one goes the warmer it gets
  (FALSE). Once we went far enough south to go past
  the equator the temperatures would start getting
  colder again.
• As latitude increases, temperature decreases

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Other Factors

• Prevailing Winds
• Regular, predictable, normal wind direction. They
  are caused by global convection cells in the
  earth's atmosphere.
• Ocean Currents
• The biggest factor besides the sun. If the water
  is warm, the temperatures will be more moderate.
• Altitude
• the higher the altitude, the cooler it will be.
• Rate is about 1 per 100m

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Altitude
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WIND

• Winds Blow From High Pressure to Low Pressure
• Any real examples of this at work?
• Air inside a balloon. If left untied the air will
  escape the high pressure of the balloon and
  create a wind blowing from high pressure (inside
  the balloon) to relatively low pressure (outside
  the balloon).
• High and low pressures in the earths atmosphere
  are responsible for wind.

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High vs. Low Pressure

• Low Pressure
• Usually a result of heating
• High Pressure
• Usually a result of cooling

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Sea Breeze/Land Breeze

• What heats faster land or water?
• When do things warm or cool over the course of 24
  hours?
• During the day the land heats much faster than
  the water
• Consequently the air over the land heats and
  rises (low pressure) while the air over the
  water/sea is relatively high
• Wind blows from the high pressure to the low
  pressure
• Hence the name 'sea breeze'the wind is blowing
  off the sea.

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During the Day
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Convection Cells

• The global convection cells are created because
  of the differential heating of the earth's
  surface.
• Alternating high and low pressure belts result
  from the convection cells.
• You want real results?

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Convection Cells
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The results?

• Every desert in the world is found at a similar
  latitude
• Every rainforest of the world is found at a
  similar latitude.
• Coincidence?

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Types of Rain

• Three types of rainfall
• Relief Rain
• Convectional
• Frontal / Cyclonic Rain

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Rain. Period.

• hot air rises
• warm moisture-laden air cools at higher altitude
• cool air holds less moisture
• consequently clouds condense and rain falls.

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Relief Rainfall

• Moisture laden air blows off the sea
• Air is forced up by mountains (high relief)
• Most rain falls on the windward side of the
  relief
• Leeward side is often in a dry rain shadow
  because the moisture has all been lost.

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Relief Rainfall
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Convectional Rainfall

• Usually occurs in hot areas like tropics or
  continental summer (Winnipeg thunderstorms)
• sun heats the earth causing large amounts of
  water to evaporate
• Then what?
• Remember RAIN.PERIOD. Check it out!

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Convectional Rainfall
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Frontal / Cyclonic Rainfall

• Warm moist air meets cold air
• Warm air is less dense is forced up over the
  cooler, more dense air
• Then What?
• Fall/spring/some summer Winnipeg rains

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Frontal Rainfall
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Ocean Currents

• Permanent horizontal movement of surface water
  (the top 100m)
• It is unusually cold or warm, when compared with
  the surrounding water
• Analogy
• SunCEO of climate
• Ocean CurrentsBOSS of climate

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Where do they go?

• Where would you expect cool currents to start
  from?
• Where would you expect warm currents to start
  from?
• How do currents create balance in the world?

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Warm and Cold Currents

• Cold ocean currents move water towards the
  equator.
• For example the Humbolt or Peru Current carries
  cold water from Antarctica toward the equator.
• Another example is the Labrador Current which
  carries cold water from the Arctic Ocean.
• Warm ocean currents Move water away from warm
  equatorial regions.
• For example the Gulf Stream moves warm water from
  the Gulf of Mexico northeast toward England.
• Another good example is the Japanese current
  which moves warm water from Japan northeast
  towards Vancouver.

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Ocean Currents the Affect on Climate

• Affect of cold ocean currents
• Cools the summer temperature
• Reduces precipitation cooler air holds less
  moisture.
• Affect of warm ocean currents
• Warms the winter temperature
• Increases precipitation warmer air holds more
  moisture.
• El Nino

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Continentality

• Temperature range the difference between the
  highest and the lowest average monthly
  temperatures of a region.
• What helps creates this range in this case?
• Proximity to ocean (or larger body of water)
• Large or high temperature range extremes of
  temperature, hot summer, cold winter (Winnipeg).
• Small or low temperature range moderated
  temperature, warm summer, cool winter (Victoria)

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Continental vs. Maritime Climates

• As distance from the ocean increases, annual
  temperature range increases.
• Continental climates experience greater extremes
  of temperature than coastal climates at the same
  latitude.
• The plains region of Saskatchewan, for example,
  experience a continental climate. The winter
  temperatures are very cold, and the summer
  temperatures are fairly hot. Range could be from
  -40 to 40C
• Close to the ocean, Victoria experiences a much
  more moderate climate. Range is from -5 to
  25. Not too cold, but at the same time, not too
  hot in the summer.

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Climate Graphs

• Give us a yearly climate snap-shot of a given
  place
• Temperature will always be shown with a line
  graph
• Precipitation will always be shown with bar graphs

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Maritime

• Scotland.

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Continental

• Winnipeg

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Tropical Climates

•  All Tropical Climates have average temperatures
  over 18C every day
• All Tropical climates can be divided into
• a) Tropical Wet b) Tropical Wet and
  Dry
• Almost all of the tropical wet / wet dry
  climates are located between the tropic of cancer
  and the tropic of Capricorn (23.5 N and S).

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Tropical Wet Climate
Tropical Wet heavy rain all year due to hot
temp resulting convectional rain.
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Tropical Wet and Dry Climate

• Tropical Wet Dry very heavy summer rain very
  dry winter due to seasonal shift in prevailing
  winds. (monsoon regions)

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Dry Climates

• All Dry climates receive less than 500mm
  precipitation annually.
• Dry Climates can be divided into
• a) Arid b) Semi-Arid
• more evaporation than precipitation water
  deficit.
• There is little vegetation it is often windy

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Arid or Desert Climates

• Arid Climates occur mostly between 10-30N
  10-30S and receive 10-250mm rain annually.

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Semi-Arid Climate

• Semi-arid Climates are transition zones between
  Desert Forest. They receive 250-500mm rain
  annually which is often enough to support grasses
  but not forests.

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Temperate Climates

• Usually in higher latitudes (above 30 N and S)
• Temperate Climates can be divided into
• a)Temperate Mild Climates occur in both
  hemispheres
• b)Temperate Cold Climates only occur in the
  northern Hemisphere. (Winnipeg)
• The distinguishing feature on a climate graph is
  the temperature line (yearly average Temp.)

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Temperate Climates

• Temperate Mild Winter
• Temperature varies with seasons
• Mid Latitudes
• Mild winter
• Summer temperatures vary but winters are warmer
  than 3ºC
• Temperate Cold Winter
• Temperature varies with seasons
• Mid-high Latitudes
• cold winters
• Summer temperatures vary but winters are colder
  than 3ºC

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Temperate Climate
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Polar Climates

• Polar climates are distinguished by their
  extremely low winter temperatures and low summer
  temperatures.
• Polar Climates can be divided into
• Tundra summer temperature never above 10C
• Ice Caps summer's average monthly temperature is
  never above 0C

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Polar Climate
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Monsoons

• A sudden wet season in the tropics. Notice the
  difference between the annual rainfall of some
  rainy places directly influenced by monsoons

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Indias Monsoons
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Indias Monsoons

• Indias Winter Monsoon
• Continental Asia cools high atmospheric
  pressure results
• Wind blows southward towards the low pressure
  over Indian ocean
• Very little rain or dry season results because
  the wind is blowing over dry land and does not
  pick up moisture.
• Indias Summer Monsoon
• Continental Asia heats up low atmospheric
  pressure results
• Wind blows northward towards the low pressure
  over India
• Tremendous rains result because the wind is
  blowing over the warm Indian Ocean.

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Indias Monsoons
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Affect on People

• Tourism in the tropics is very important. During
  monsoons, travel is not safe, even prohibited in
  some cases (Malaysias East Coast)
• Severe flooding
• Economy suffers (fishing, tourism, etc.)