1

Climate

Earth ScienceChapter 20

Pages 560-573

Elements of weather and climate• Temperature

– Range of temperature– Seasonal temperature pattern

• Rainfall– Overall rainfallOverall rainfall – Seasonal distribution of rainfall– Compared to evaporation potential

• Pressure– Predominant pressure– Seasonal fluctuation of pressure

Weather vs. Climate

• Climate is the weather you expect• Weather is what you get, whether you

expect it or not

• (Note: if you spell it ‘whether’ it has a different meaning)

Atmospheric Circulation Ocean circulation Jan and July temps

Values used for Koppen System

• Overall temperature• Evaporation compared to precipitation• Absolute rainfall• Rainfall distribution• Extreme temperature

World climate map Koppen Climate System

• A tropical: wet, monsoon, dry w/s• B dry: desert/steppe, low/mid latitude• C humid mid-latitude, mild winter:

t d ‘ t t’wet summer, dry summer ‘west coast’• D humid mid-latitude severe winter• E polar: tundra, ice cap• H highland: modified version of local

lowland area—cooler, moister

2

Af Tropical rainforest A Tropical climates

• NEVER COLD• Rain forest—always wet• Monsoon—extreme seasonal rainfall• Savannah—very dry months

A Climatic diagrams

Monsoon Climate

http://www.freewebs.com/scienceandsociety/summermonsoonpdem2.gif

Tropical Monsoon

• Due to arrival of ITCZ in a local area at a certain season

• ITCZ migrates out of area, leaving a distinct dry seasondistinct dry season

• Southern Asia, Sothwestern Pacific islands, Western Equatorial Africa, Northeastern South America,

Aw Tropical Savannah

Tropical Savanna

• Never cold• Pronounced dry season: lasts longer than

wet seasonW t i ’t t• Wet season isn’t as wet as monsoon climate

Subtropical desert

http://www.gerber-travel.ch/Tours/libya_1999_5.htm

B Dry climates

• EVAPORATION POTENTIAL EXCEEDS PRECIPITATION

• Low latitude deserts always warmS bt i l hi h– Subtropical high pressure

– 20°-30° N and S of equator• Mid latitude deserts can be quite cold

– Further poleward than low latitude deserts– Rain shadow effect

3

Cold desert

http://www.asphalto.org/?user_id=907&PHPSESSID=a55...

B Cilmate Diagrams Steppe Climate

• Transition from desert climate to another climate next to the desert

• Not as dry as desertD t h ti d t• Desert has more evaporation compared to rainfall than steppe

• Dessert: mmm….cake (Do you see they are spelled differently?)

Sub-tropical Steppe

http://os.inf.tu-dresden.de/~nf2/nz_farewell/

Mid latitude steppe

http://61966.rapidforum.com/topic=101082217975

Worldwide arid zones

C Mild mid-latitude climate

• Humid• MILD WINTER• Divisions:

– Hot summer: dry or wet– Warm summer: dry or wet– Marine west coastal climate

• unique subdivision of dry summer that extends far poleward of other mild climates

• Moderated by the ocean and the westerlies

Mild Humid wet all year

http://www.us-parks.com/images/everglades-national-park/plantlife-of-everglades-p-3629-m.jpg

Mild, Dry summer climate

http://usparks.about.com/od/nationalparksus/ig/santamonicaphotos/Scenery11.htm

4

C Climate Diagrams Marine west coast

http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/climate_systems/marine_west_coast.html

Coastal Alaska

• Northern mild climate due to incoming moist air from ocean by westerlies

http://thewondersofnature.com/bears/co_scenery_01.html

D Severe mid latitude

• SEVERE WINTERS• Humid continental

– Cold winterW t– Wet summer

– Hardwood forests• Subarctic

– Not warm in summer– Needle-leaf evergreens– ‘Taiga’

D Climate Diagrams Humid continental severe winter

http://www.public.iastate.edu/~glh/NATREGION/FRONTIMAGES/front6.jpg

Midlatitude humid continental

http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/biogeography/biomes_midlatitude_forests_page_1.html

Midlatitude humid continental

http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/biogeography/biomes_midlatitude_forests_page_1.html

Taiga

5

E Polar climate

• TOO COLD FOR TREES• Tundra some month is above freezing• Ice cap no months are above freezing

Tundra E Climate Diagrams

Ice cap climate

http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/climate_systems/icecap.html

World climate map Highland

• Modified version of local climate• Cooler, moister

Lowland adjacent to H Highland differenceH compared to

adjacent climate