CLIMATECLIMATE

Day vs. NightDay vs. Night

Earth Earth rotatesrotates on it’s axis (24 hours). on it’s axis (24 hours).

Results in day and nightResults in day and night

SeasonsSeasons

Earth Earth revolvesrevolves around the Sun around the Sun (orbits 365 days).(orbits 365 days).

Results in seasonsResults in seasons

Cloud CoverCloud Cover Cloud CoverCloud Cover::

Nightly cloud cover will result in Nightly cloud cover will result in less less temperature range temperature range (like a blanket)(like a blanket)

Without cloud cover, heat escapes (at night), Without cloud cover, heat escapes (at night), but temperature range is very high (hot days, but temperature range is very high (hot days, cold nights…the desert)cold nights…the desert)

Differences in Day LengthDifferences in Day Length

JUNE DECEMBER

SUN

The tilt of the earth’s axis combined with the earth’s 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.

SEASONSSEASONS

The The tilttilt on the earth's axis and; on the earth's axis and; The The revolutionrevolution of the earth around of the earth around

the sun the sun These two features of the earth-sun These two features of the earth-sun

relationship mean that different relationship mean that different latitudes on earth receive different latitudes on earth receive different directness of light at different times. directness of light at different times.

Equinox and SolsticeEquinox and Solstice SolsticeSolstice::

sun is directly over head @ 12 noon on 23.5º sun is directly over head @ 12 noon on 23.5º North or South; North or South;

occurs occurs Dec 21 & June 21 Dec 21 & June 21 longest day of the year & shortest day of the longest day of the year & shortest day of the

year. year. EquinoxEquinox: :

sun is directly over head @ 12 noon on the sun is directly over head @ 12 noon on the equator; equator;

occurs occurs Sept. 21 & March 21 Sept. 21 & March 21 equal length of night and day everywhere on equal length of night and day everywhere on

earth. earth.

Tropics vs. The PolesTropics vs. The Poles

The tropics are located between The tropics are located between 23.5˚ 23.5˚ north north and and 23.5˚ south23.5˚ south(Cancer and (Cancer and Capricorn)Capricorn)

The further you move away from the The further you move away from the tropics the more severe the seasons. tropics the more severe the seasons.

The length of day varies more the further The length of day varies more the further you move from the equator. you move from the equator.

When light hits the earth towards the When light hits the earth towards the poles it is on a severe angle which poles it is on a severe angle which decreases the intensity of heat. decreases the intensity of heat.

How the Sun hits the EarthHow the Sun hits the Earth

Greenhouse EffectGreenhouse Effect A good thing? A good thing? In moderation of course; moderates our In moderation of course; moderates our

temperaturestemperatures Without we would have extreme variation Without we would have extreme variation

of temperatures between day and nightof temperatures between day and night Atmosphere reflects and absorbs about Atmosphere reflects and absorbs about

50% of radiant energy50% of radiant energy Without atmosphere, planets have nothing Without atmosphere, planets have nothing

to hold heat in (like the glass in a to hold heat in (like the glass in a greenhouse… consequently the nights are greenhouse… consequently the nights are not as cool)not as cool)

Latitude and Latitude and TemperatureTemperature

The closer we get to the equator, the The closer we get to the equator, the warmer it gets warmer it gets

““The further south one goes the The further south one goes the warmer it getswarmer it gets”” (FALSE). Once we (FALSE). Once we went far enough south to go past the went far enough south to go past the equator the temperatures would start equator the temperatures would start getting colder again. getting colder again.

As latitude increases, temperature As latitude increases, temperature decreasesdecreases

Other FactorsOther Factors

Prevailing WindsPrevailing Winds Regular, predictable, normal wind direction. They Regular, predictable, normal wind direction. They

are caused by global convection cells in the are caused by global convection cells in the earth's atmosphere. earth's atmosphere.

Ocean CurrentsOcean Currents The biggest factor besides the sun. If the water is The biggest factor besides the sun. If the water is

warm, the temperatures will be more moderate. warm, the temperatures will be more moderate.

AltitudeAltitude the higher the altitude, the cooler it will be.the higher the altitude, the cooler it will be. Rate is about 1˚ per 100mRate is about 1˚ per 100m

AltitudeAltitude

WINDWIND

Winds Blow From High Pressure to Winds Blow From High Pressure to Low Pressure Low Pressure

Any real examples of this at work?Any real examples of this at work? Air inside a balloonAir inside a balloon. If left untied the air will . If left untied the air will

escape the high pressure of the balloon and escape the high pressure of the balloon and create a wind blowing from high pressure (inside create a wind blowing from high pressure (inside the balloon) to relatively low pressure (outside the balloon) to relatively low pressure (outside the balloon).the balloon).

HighHigh and and lowlow pressures in the earth pressures in the earth’’s s atmosphere are responsible for wind. atmosphere are responsible for wind.

High vs. Low PressureHigh vs. Low Pressure

Low Pressure: Low Pressure:

Usually a result of Usually a result of ““heatingheating”” High Pressure: High Pressure:

Usually a result of Usually a result of ““coolingcooling””

Sea Breeze/Land BreezeSea Breeze/Land Breeze

What heats faster; land or water?What heats faster; land or water? When do things warm or cool over the When do things warm or cool over the

course of 24 hours?course of 24 hours? During the day the land heats much faster than the During the day the land heats much faster than the

water; water; Consequently the air over the land heats and rises Consequently the air over the land heats and rises

((lowlow pressure) while the air over the water/sea is pressure) while the air over the water/sea is relatively relatively highhigh; ;

Wind blows from the high pressure to the low Wind blows from the high pressure to the low pressure pressure

Hence the name 'sea breeze'—the wind is blowing Hence the name 'sea breeze'—the wind is blowing off the sea. off the sea.

During the DayDuring the Day

Convection CellsConvection Cells

The global The global convection cellsconvection cells are are created because of the differential created because of the differential heating of the earth's surface. heating of the earth's surface.

Alternating Alternating high and low pressure high and low pressure belts belts result from the convection result from the convection cells. cells.

You want real results?You want real results?

Convection CellsConvection Cells

The results?The results?

Every desert in the world is found at Every desert in the world is found at a similar latitudea similar latitude

Every rainforest of the world is Every rainforest of the world is found at a similar latitude.found at a similar latitude.

Coincidence?Coincidence?

Types of RainTypes of Rain

Three types of rainfallThree types of rainfall::1.1. Relief RainRelief Rain

2.2. Convectional Convectional

3.3. Frontal / Cyclonic RainFrontal / Cyclonic Rain

Rain. Period.Rain. Period.

hot air rises hot air rises warm moisture-laden air cools at warm moisture-laden air cools at

higher altitude higher altitude cool air holds less moisture; cool air holds less moisture; consequently clouds condense and consequently clouds condense and

rain falls. rain falls.

Relief RainfallRelief Rainfall

Moisture laden air blows off the sea; Moisture laden air blows off the sea; Air is forced up by mountains (high relief)Air is forced up by mountains (high relief) Most rain falls on the Most rain falls on the windward side windward side of of

the relief the relief Leeward side Leeward side is often in a dry is often in a dry rain shadow rain shadow

because the moisture has all been lost. because the moisture has all been lost.

Relief RainfallRelief Rainfall

Convectional RainfallConvectional Rainfall

Usually occurs in Usually occurs in hot areas hot areas like like tropics or continental summer tropics or continental summer (Winnipeg thunderstorms)(Winnipeg thunderstorms)

sun heats the earth causing large sun heats the earth causing large amounts of water to evaporateamounts of water to evaporate

Then what? Then what? Remember RAIN.PERIOD. Check it Remember RAIN.PERIOD. Check it

out!out!

Convectional RainfallConvectional Rainfall

Frontal / Cyclonic Frontal / Cyclonic RainfallRainfall

Warm moist air meets cold air Warm moist air meets cold air Warm air is less dense & is forced Warm air is less dense & is forced

up over the cooler, more dense airup over the cooler, more dense air Then What? Then What? Fall/spring/some summer Winnipeg Fall/spring/some summer Winnipeg

rainsrains

Frontal RainfallFrontal Rainfall

Ocean CurrentsOcean Currents

Permanent horizontal movement of Permanent horizontal movement of surface water (the top 100m) surface water (the top 100m)

It is unusually It is unusually cold or warmcold or warm, when , when compared with the surrounding compared with the surrounding water water

Analogy:Analogy: SunSun=CEO of climate=CEO of climate Ocean CurrentsOcean Currents=BOSS of climate=BOSS of climate

Where do they go?Where do they go?

Where would you expect Where would you expect cool currents cool currents to start from?to start from?

Where would you expect Where would you expect warm warm currents currents to start from?to start from?

How do currents create balance in the How do currents create balance in the world?world?

Warm and Cold CurrentsWarm and Cold Currents Cold ocean currents: move water towards the Cold ocean currents: move water towards the

equator. equator. For example the For example the Humbolt or Peru Current Humbolt or Peru Current carries carries

cold water from Antarctica toward the equator. cold water from Antarctica toward the equator. Another example is the Another example is the Labrador Current Labrador Current which which

carries cold water from the Arctic Ocean. carries cold water from the Arctic Ocean. Warm ocean currents: Move water away from Warm ocean currents: Move water away from

warm equatorial regions. warm equatorial regions. For example the For example the Gulf Stream Gulf Stream moves warm water moves warm water

from the Gulf of Mexico northeast toward England. from the Gulf of Mexico northeast toward England. Another good example is the Another good example is the Japanese current Japanese current

which moves warm water from Japan northeast which moves warm water from Japan northeast towards Vancouver. towards Vancouver.

Ocean Currents & the Ocean Currents & the Affect on ClimateAffect on Climate

Affect of cold ocean currentsAffect of cold ocean currents

Cools the summer temperature; Cools the summer temperature;

Reduces precipitation; cooler air holds less Reduces precipitation; cooler air holds less moisture. moisture.

Affect of warm ocean currents Affect of warm ocean currents

Warms the winter temperature; Warms the winter temperature;

Increases precipitation; warmer air holds Increases precipitation; warmer air holds more moisture. more moisture.

El NinoEl Nino

ContinentalityContinentality Temperature rangeTemperature range: : the difference the difference

between the highest and the lowest between the highest and the lowest average monthly temperatures of a region. average monthly temperatures of a region.

What helps creates this range in this case?What helps creates this range in this case?Proximity to ocean (or larger body of water)Proximity to ocean (or larger body of water) Large or high temperature rangeLarge or high temperature range: : extremes of extremes of

temperature, hot summer, cold winter (Winnipeg). temperature, hot summer, cold winter (Winnipeg). Small or low temperature rangeSmall or low temperature range: : moderated moderated

temperature, warm summer, cool winter (Victoria)temperature, warm summer, cool winter (Victoria)

Continental vs. Maritime Continental vs. Maritime ClimatesClimates

As distance from the ocean increases, As distance from the ocean increases, annual temperature range increasesannual temperature range increases. .

Continental climates experience greater extremes of Continental climates experience greater extremes of temperature than coastal climates at the same latitude. temperature than coastal climates at the same latitude.

The plains region of Saskatchewan, for example, The plains region of Saskatchewan, for example, experience a continental climate. The winter experience a continental climate. The winter temperatures are very cold, and the summer temperatures are very cold, and the summer temperatures are fairly hot. Range could be from: -temperatures are fairly hot. Range could be from: -40° to 40°C40° to 40°C

Close to the ocean, Victoria experiences a much more Close to the ocean, Victoria experiences a much more moderate climate. Range is from: -5moderate climate. Range is from: -5° to 25°. Not too ° to 25°. Not too cold, but at the same time, not too hot in the summer. cold, but at the same time, not too hot in the summer.

Climate GraphsClimate Graphs

Give us a Give us a yearly climate snap-shot yearly climate snap-shot of of a given placea given place

Temperature will always be shown Temperature will always be shown with a line graphwith a line graph

Precipitation will always be shown Precipitation will always be shown with bar graphswith bar graphs

MaritimeMaritime

Scotland….Scotland….

ContinentalContinental

WinnipegWinnipeg

Tropical ClimatesTropical Climates

  All Tropical Climates have average All Tropical Climates have average temperatures temperatures over 18˚C over 18˚C every dayevery day

All Tropical climates can be divided into:All Tropical climates can be divided into:

a) Tropical Wet b) Tropical Wet a) Tropical Wet b) Tropical Wet and Dryand Dry

Almost all of the Almost all of the tropical wet / wet & dry tropical wet / wet & dry climatesclimates are are located between located between the tropic the tropic of cancer and the tropic of Capricorn of cancer and the tropic of Capricorn (23.5˚ N and S)(23.5˚ N and S). .

Tropical Wet ClimateTropical Wet Climate

Tropical Wet : heavy rain all year due to hot temp & resulting convectional rain.

Tropical Wet and Dry Tropical Wet and Dry ClimateClimate

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

Dry ClimatesDry Climates

All Dry climates receive All Dry climates receive less than less than 500mm 500mm precipitation annually. precipitation annually.

Dry Climates can be divided into:Dry Climates can be divided into:

a) Arid b) Semi-Arida) Arid b) Semi-Arid more evaporation than precipitation = more evaporation than precipitation =

water deficit. water deficit. There is little vegetation & it is often There is little vegetation & it is often

windy windy

Arid or Desert ClimatesArid or Desert Climates

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

Semi-Arid ClimateSemi-Arid Climate

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

Temperate ClimatesTemperate Climates Usually in higher latitudes (above 30˚ Usually in higher latitudes (above 30˚

N and S)N and S) Temperate Climates Temperate Climates can be divided can be divided

into:into: a)Temperate Milda)Temperate Mild ClimatesClimates occur in occur in

both hemispheres both hemispheres b)Temperate Cold Climatesb)Temperate Cold Climates only occur only occur

in the northern Hemisphere. (Winnipeg)in the northern Hemisphere. (Winnipeg) The distinguishing feature on a climate The distinguishing feature on a climate

graph is the temperature line (graph is the temperature line (yearly yearly average Tempaverage Temp.).)

Temperate ClimatesTemperate Climates Temperate Mild WinterTemperate Mild Winter

Temperature varies with seasons Temperature varies with seasons Mid Latitudes Mid Latitudes Mild winter Mild winter Summer temperatures vary but winters are Summer temperatures vary but winters are

warmer than –3ºC warmer than –3ºC Temperate Cold WinterTemperate Cold Winter

Temperature varies with seasons Temperature varies with seasons Mid-high Latitudes Mid-high Latitudes cold winters cold winters Summer temperatures vary but winters are Summer temperatures vary but winters are

colder than –3ºC colder than –3ºC

Temperate ClimateTemperate Climate

Polar ClimatesPolar Climates

Polar climates Polar climates are distinguished by are distinguished by their extremely low winter their extremely low winter temperatures and low summer temperatures and low summer temperatures. temperatures.

Polar Climates Polar Climates can be divided into:can be divided into: TundraTundra: summer temperature : summer temperature never never

above above 10˚C10˚C Ice CapsIce Caps: summer's average monthly : summer's average monthly

temperature is temperature is never above never above 0˚C 0˚C

Polar ClimatePolar Climate

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MonsoonsMonsoons

A sudden wet season in the tropicsA sudden wet season in the tropics. . Notice the difference between the Notice the difference between the annual rainfall of some annual rainfall of some ““rainyrainy”” places places directly influenced by monsoons directly influenced by monsoons

India’s MonsoonsIndia’s Monsoons

India’s MonsoonsIndia’s MonsoonsIndiaIndia’’s Winter Monsoons Winter Monsoon Continental Asia cools & high atmospheric pressure Continental Asia cools & high atmospheric pressure

results; results; Wind blows southward towards the low pressure over Wind blows southward towards the low pressure over

Indian ocean; Indian ocean; Very little rain or dry season results because the wind is Very little rain or dry season results because the wind is

blowing over dry land and does not pick up moisture. blowing over dry land and does not pick up moisture. IndiaIndia’’s Summer Monsoons Summer Monsoon Continental Asia heats up & low atmospheric pressure Continental Asia heats up & low atmospheric pressure

results; results; Wind blows northward towards the low pressure over Wind blows northward towards the low pressure over

India; India; Tremendous rains result because the wind is blowing Tremendous rains result because the wind is blowing

over the warm Indian Ocean.over the warm Indian Ocean.

India’s MonsoonsIndia’s Monsoons

Affect on PeopleAffect on People Tourism Tourism in the tropics is very important. During monsoons, travel in the tropics is very important. During monsoons, travel

is not safe, even prohibited in some cases (Malaysiais not safe, even prohibited in some cases (Malaysia’’s East Coast)s East Coast) Severe floodingSevere flooding Economy suffers Economy suffers (fishing, tourism, etc.)(fishing, tourism, etc.)