1. Climatic Controls Latitude Altitude Continentality Prevailing Wind
Air Mass Variability
Topography
Ocean Currents
Land Use / Land Cover Change

2. Empiric classification: Köppen and later modified by Thornthwaite and Trewartha
looked at the global distribution of different plant and animal species and attempted to see how weather variables correlated with these patterns.
Temperature and precipitation

3. Köppen climate classification
Five primary categories
A Tropical
B Dry
C Mesothermal- “moderate”
D Microthermal- “low”
E Polar

4. BASIC WORLD CLIMATES

6. A climates Mean temperature of coldest month is above 18°C (64°F)
Essentially, no freezes
Tropical Rainy: no dry season
Tropical Wet-and-Dry: short dry season
Tropical Monsoon: long dry season

7. TROPICAL RAINFOREST Annual precip > 80” No real seasons
Sticky, humid air, with little wind
High sun angle all year

8. Tropical Savanna and Monsoon
alternating 3 month wet and dry periods dominated by movement of ITCZ
Monsoon
5 - 7 month wet and dry regime
Both have 40 – 80” precip/year and average temps above 64°F every month

9. B climates
Arid and Semi-arid
P < PE
BW (Desert):
BS (Steppe):

10. Steppes Dry short grass regions surrounding deserts
There are cold and hot steppes
Hot steppes are subtropical
South Texas
Cold steppes are at mid latitudes
Montana
Both have approximately 10 – 20” annual precip

11. Deserts Hot and Cold deserts just like Steppes
Both have < 10” precip/year
Abundant sunshine
Hot desert
Sahara
Cold desert
Gobi

12. C climates
Essentially, it freezes but snow is not permanently on the ground in winter.
Mediterranean: dry summer
Wet-and-dry: dry winter
Humid: no dry season

13. Humid Subtropical
Mild winters with temperatures frequently dipping below freezing (northern limits) to infrequent freezes (southern limits)
Hot summers
Abundant precip throughout the year
SE U.S.

14. Mediterranean (dry summer subtropical)
No summer rain
Very little late spring/early fall rain
Cool moist winters and warm summers
Climate moderated by cold water
Abundant sunshine
Southern Cal

15. Marine West Coast Cool/cold and moist winters
Pleasant summers with temps generally not exceeding 85°F
Summer is drier
Persistent fog, drizzle, gray skies for the majority of the year
Seattle, London

16. D climates Coldest month is less than -3°C; warmest month above 10°C.
Essentially, where snow remains on the ground for part of the winter.
Wet-and-dry: dry winter
Humid: no dry season

17. Humid Continental Cold winters and warm summers Precip in every month
Northern U.S.
Humid Continental (cool summers)
Located farther north with colder winters
Southern canada

18. Subarctic Boreal or Taiga
Brutal winters
Coniferous forests
Short cool summer with average temps breaking 50F and frequently reaching the 70s
Not much precip 10 – 20”
Northern Hemisphere only
Most of Canada, Russia

19. E climates Warmest month below 10°C.
Essentially, where it’s too cold for trees to grow
Tundra: it thaws in summer
Ice Cap: it doesn’t

20. Tundra and Icecap Tundra is treeless Average temps do not break 50°F
Small flowering plants, lichens, mosses,
Horrible insects in summer when permafrost thaws
Icecap is frozen year round
Occasionally temperatures will rise above freezing

21. Alpine or Highland Complex climates because of altitude
Can be a little of everything depending on the elevation

23. WORLD CLIMATES

25. ANNUAL PRECIP