Climate ControlsWhy does temperature vary so much in the world?

PSALMON

Prevailing Winds:• Low pressure around the equator and mid-latitudes (30-60

degrees) = have much precipitation• High Pressure around sub tropical (30 N/S) and poles (90

N/S) have little rainfall.• Mid-latitudes are changeable and they have precipitation

in the winter (low pressure) and high pressure in the summer (clear-sunny skies)

https://www.youtube.com/watch?v=uBqohRu2RRk

Slope of the Land (also known as Aspect)- largely a micro-climatic controlDirection a slope facesIn the northern hemisphere:• south facing slopes are drier (more sunshine)• north facing slopes are wetter and have less sun• https://www.youtube.com/watch?v=YegLPjbMeZk

Altitude: the higher you go up, the colder it gets.

Why? Less dust, greenhouse gases, water vapour, etc. to trap heat coming up from the earth's surface. Air is thinner!

https://www.youtube.com/watch?v=cimgIhtN-AU

Latitude: the further north you go in the northern hemisphere, the colder it gets.

Why?

Sun’s Rays are more spread and earth’s tilt

https://www.youtube.com/watch?v=UQjT5uKp2hg&feature=youtu.be

Mountain Barriers: impede the movement of cold air masses. This is due to the fact that cold air is dense and generally stays near to the ground.

• Air is forced to rise on the windward side of mountain causing precipitation• Leeward side the wind falls creating clear, dry conditions=rain shadow

eg Vancouver is shielded from most Arctic air masses by the Rockies and Coast Mountains.

Mountains can also result in warm winds descending down slope

eg 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.

• https://www.youtube.com/watch?v=H9ZK1CnjCFo•

Ocean Currents: can either warm or cool a coastal area by approximately two degrees Celsius. • Warm and cold ocean currents circulate through out the world’s oceans and these have a

heating/cooling effect• Gulf Stream (warm current) warms areas in Europe (Britain) making the climate

moderate• Cold Ocean Currents will create dry regions around the globe=Atacama desert in Chile is

a result of cold ocean currents as the bring dry air from the see over land• https://www.youtube.com/watch?v=HrH5GPES4_4• Note: Winds produce currents.

eg Los Angeles: California Current (cool)Halifax: Gulf Stream Current (warm)Pages 147 to 148 in Planet Earth: A Physical Geography

Nearness to Water or Continentality: the closer a city is to a large body of water, the more moderate will be its temperatures (i.e. maritime climate), whereas the further away a city is from the water, the greater the temperature extremes (i.e. continental climate).

• Locations near water=wetter/moderate• Interior (Continental) locations are drier and have more temperature

extremes• Ex. Gobi Desert in Mongolia/China (dry interior conditions)Try to think of differences in climate between a place like Vancouver and

Winnipeg…https://www.youtube.com/watch?v=uBqohRu2RRk

Climates of the World

Introduction• Weather refers to the current state of the atmosphere. Climate involves long term averages of

temperature and precipitation. • In the previous unit, you learned about the three processes of precipitation (convectional,

orographic, and frontal) as well as factors that influence temperature (i.e. O LAMPNAS). Keep these in mind, as you progress through this unit.

http://www.classzone.com/books/earth_science/terc/content/visualizations/es2103/es2103page01.cfm?chapter_no=visualization

http://www.blueplanetbiomes.org/climate.htm (it’s the best)

http://www.uwsp.edu/geO/faculty/ritter/geog101/uwsp_lectures/lecture_climate_class.html (this is an unbelievable website

http://www.learner.org/resources/series78.html?pop=yes&vodid=482602&pid=312# (free videos)

http://www.worldbook.com/wb/Students?content_spotlight/climates/about_climates

http://www.kbears.com/climates.html (childish, but education!)

http://members.aol.com/bowermanb/weathergames.html (games) great website!

Tropical ClimatesA) Tropical Climates: Warm temperatures all

year.

1) Equatorial or Tropical WetClimate Explanation:• - low latitude: direct rays of the sun overhead

allows for maximum heating resulting in

• warm temperatures and active convectional precipitation

• - near the equatorial Low pressure zone-Prevailing Winds

Locations:

Brazilian Rainforest

Indonesia

Zaire (equatorial portion of Africa)

2) Tropical Wet and DryClimate Explanation:• - similar to Equatorial in terms of temp.

• - active convectional precipitation for part of the year and then dry for the remainder due to the influence of the subtropical High anchored at 30 N or S – Prevailing Winds and Latitude

A Baobab tree, with its thick trunk and large edible fruit, Dakar, Senegal.

Locations:

Ibadan, Nigeria

Sudan

Mexico

3) Monsoon

Climate Explanation :• - in "Summer", tremendous heat over the Indian

subcontinent forms a Low while the ocean which heats up slower maintains a High. Therefore, wind blows onshore from

High to Low bringing tremendous rainfall (Note: Notice the scale is different for the Monsoon climate graph in order to accommodate the tremendous precipitation from June to September.)

• - in "Winter", the land cools down quicker than the ocean over northern India and Nepal.

• Therefore, a High forms over the land and a Low over the ocean. The Wind blows offshore bringing much drier conditions.

Note: In order to differentiate between a Monsoon climate

and a Tropical Wet / Dry climate, look at

the precipitation amounts in the summer months. There is

considerably more for the Monsoon

climate such that the scale is changed to accommodate the

larger quantities of precipitation.

Bombay, India

Locations:

India

Thailand

B) Arid Climates: Low precipitation all year.1) Tropical Desert (Hot Desert)• Climate Explanation:• - low latitude (20 to 30 N & S), therefore

hot when sun directly overhead• i.e. June, July, and Aug. in the northern

hemisphere• - dry due to influence of subtropical High

pressure area at 30 N or Shigh pressure – Sahara Desert (Northern

Africa)cold ocean currents – Atacama Desert (Chile)• − continentality – Gobi Desert (China)• − rain shadow – Mojave Desert

(California) -

Cairo, Egypt

Locations:

Southern California

Baja, Mexico

Northern Africa

Middle East

2) Cold Desert, ArcticClimate Explanation:• - under the full influence of the

Arctic or Antarctic High Pressure Area, therefore dry

• - high latitude (i.e. > 65 N or S), therefore sun's rays spread out resulting in little heating

Scientist exploring Taylor Glacier in McMurdo Sound, Victoria Land, Antarctica

Locations:

Northernmost Portion of Russia

Greenland

Northernmost portion of Canada-Nunavut

C) Coastal Climates : Moderate temperature ranges with moderate precipitation.

1) Cool Climate - Moderate Winter or Maritime (eg Vancouver and London, England)

Climate Explanation :• - orographic precipitation caused by

coastal mountain barrier and onshore wind flow

• - frontal precipitation during Fall, Winter, and Spring due to meeting of different air masses from the north and south

• - drier in Summer due to High air pressure• - nearness to water moderates

temperatures• PSALMONS-Prevailing Winds, Nearness to

water, Mountain Barrier, Ocean Currents

Coniferous forest of western Oregon.

Locations:

You better know this one!

BC

British Isles – Northern Europe

2) MediterraneanClimate Explanation :• - 30 to 40 N or S on the west side of continents• - influence of High pressure at 30 N or S keeps conditions quite clear and dry

especially in Summer• - some frontal precipitation in Winter• - found in places such as Spain, Greece, Italy and Northern California

(Sacramento)-cold ocean current for this area• During the winter the subtropical high shifts to the south and its influence is

replaced by the Westerlies associated with the subpolar low. During this period, mT, mP, and cP air masses invade the climate. Midlatitude cyclones formed in the Westerlies bring much needed precipitation during the winter.

Locations:

Sacramento, California (Northern Cali.)

Spain

Greece

3) Warm Climate – Wet –Humid Subtropical (in Sovio)Climate Explanation :• - warm / moist tropical air brings convectional precipitation

• - frontal precipitation also possible

• - threat of hurricanes from off the ocean particularly on the coast

• - threat of tornadoes eg tornado alley USA

• - low latitude: 25 to 40 N or S on east side of continents-extreme temps and lots of ppt-similar to equatorial, but further up north

Deciduous ForestNew Orleans, USA

Locations:

New Orleans

Florida

Japan

C) Continental Climates : Extreme temperature ranges with low precipitation.

1) Humid Continental (in Sovio)—Cool Climate Severe Winter in Mleziva

Climate Explanation :• - being further inland results in greater temperature

extremes with cold winters and warm summers Recall: land heats up and cools down faster than the ocean

• - most precipitation occurs in Summer in the form of convectional precipitation

• - frontal precipitation is also possible as cold air masses from the north meet warm on from the south

• - threat of tornadoes in the southerly part of this zone particularly on the Great Plains

Coniferous Forest

Ottawa, Canada

Locations:

Prairies (Saskatchewan/Manitoba)

Ottawa

2) Warm Climate – Dry Climate Explanation :• - places lie on the leeward or

rainshadow side of mountain barriers, therefore it is clearer

• and drier

• - some convectional precipitation in the heat of summer

• - inland, therefore more extreme temperatures with warm summers and cool winters but

• not as cold as the previous zone because further south

Locations:

Prairies (Alberta)

Ukraine (in between-Cool Climate-Severe Winter and Warm Climate/Dry