1. Climate Classifications October 28, 2014

2. Weather vs. Climate Weather – state of the atmosphere at a specific place and time on Earth’s surface. Climate – average values of weather elements, such as temp and precipitation, over an extended period of time “Climate is what you expect, weather is what you get.” –Mark Twain

3. Variables that Influence Climate Latitude – intensity of radiation, length of day Seasonality – annual variation of sun angle Air Circulation – predictable – weather systems Maritime/Continental – proximity to water can increase precip. and reduce temp range Topography – local topography can impact climate, e.g. windward vs. leeward side of mts.

4. Köppen Climate Classification System Describes world climates based on: – Avg monthly temp – Avg monthly precip – Total annual precip 6 major climate groups based on latitude: A-E & H Further subdivided by temp and precip.

6. Primary Letter – based on latitude – Exceptions: B and H climate types Secondary letter – based on seasonal changes in precipitation Tertiary letter – based on seasonal changes in temperature – Exceptions: A and E climate types have no tertiary letter Köppen Climate Classification System

7. Köppen’s Climate Classifications Tropical Climates (A) – Average temp of every month > 18ºC Mesothermal Climates (C) – Coldest month average temperature -3ºC – At least 1 month average temperature > 10ºC Microthermal Climates (D) – Average temperature of warmest month >10ºC – Average temperature of coldest month < -3ºC Primary Letters

8. Köppen’s Climate Classifications Polar Climates (E) – Average temperature of all months < 10ºC Dry Arid and Semiarid Climates (B) – Evaporation > precipitation Highland (H) Primary Letters

9. Köppen’s Climate Classifications Secondary Letters These letters are based primarily on seasonal precipitation: –f = adequate rainfall all through the year, no distinct dry season –w = winter dry (keep in mind the hemisphere), if 70% or more of annual rainfall occurs in summer –s = summer dry, if 70% or more of annual rainfall occurs in winter –m = extremely wet summer = monsoon. A climate only.

10. Köppen’s Climate Classifications Secondary Letters For B climate only: –S = semiarid = steppe –W = arid = desert –which results in either BS or BW. For E climate only: –T = tundra –F = perpetual frost = permanent ice –which results in either ET or EF.

11. Köppen’s Climate Classifications Tertiary Letters The third letters in the system are based exclusively on seasonal and annual temperature: –a = hot summer, warmest month > 22°C; C and D only –b = warm summer, warmest month < 22°C; C and D only –c = cool summer, < 4 months over 10°C; C and D only –d = very cold winter, coldest month < -38°C; D only –h = dry-hot, annual temperature > 18°C; B only –k = dry-cold, annual temperature < 18°C; B only

13. Köppen’s Climate Classifications Examples of Combinations Af = Tropical Rainforest climate type Am = Tropical Monsoon climate type BWh = Low-Latitude Hot Desert climate type Cfa = Humid Subtropical climate type Csa = Mediterranean climate type Dfb = Humid Continental climate type ET = Tundra climate type

15. Tropical Climates (A) Straddle Equator from 25º N to 25º S Avg. Monthly temp. exceeds 18ºC (64ºF) Subdivided by precipitation: Af – tropical rainforest – wettest Am – tropical monsoon Aw – tropical savanna - drier

17. AfAf

18. Hawaii Tropical Rainforest - Af Northern Australia Tropical Savanna - Aw India Tropical Savanna - Am

19. Arid/Semi-Arid Climates (B) Poleward of A climates on all continents Subsiding air from STHs - Moister on fringes Subdivided by temp & moisture: – BWh – 15-30º N & S – hot - little precip – BWk - <15 cm precip/yr – high temp range – BSh – more temp range & precip than BWh – BSk – rainshadow – convectional precip – high temp range

20. Arid Climates (BWh)

21. Semiarid Climates (BWk)

22. BWh

23. BWk

24. Semiarid Climates (BS)

25. BSh

26. BSk

27. Jordan – Hot, Low-latitude Desert - BWh Northcentral China – Cold, mid latitude Desert - BWk Eastern Colorado, USA Cold, mid latitude Steppe - BSk California, USA - Hot, low latitude Steppe - BSh

29. Mesothermal Climates (C) 20º- 60º N & S – where most people live A warm and a cool season Cfa, Cwa – Humid Subtropical - hot, humid summer – east side of continents – 20-35º N & S Csa, Csb – Maritime - near 35º N & S – winter wet season, dry summer Cfb, Cfc – Mediterranean - west coast of continents – 35-60º N & S – mP air & orographic processes

30. Humid Subtropical

31. Cfa

32. Maritime

33. Mediterranean

34. Csa

35. Southern California – Mediterranean Dry-Summer Climate - Csa Western Washington – Marine West-Coast Climate - Cfc

36. Microthermal Climates (D) Poleward of C climates, 35º- 60º N & S Long winters, limited summer warmth, continental climates Dfa, Dwa – large annual temp range – jet stream & cyclonic precip, most in summer Dfb, Dwb – very large annual temp range – mild summer, harsh, dry winter Dfc, Dwc, Dwd – long, bitter winters - short, cool summers – little precip – highest annual temp range on Earth

37. Microthermal Climates (D)

38. Dfa

39. Dwa

40. Eastern US – Humid Continental Hot-Summer Climate - Dfa Northern Michigan – Humid Continental Mild-Summer Climate - Dfb Central Canada - Subarctic Climate – Dfc

41. Polar Climates (E) Latitudes >70º N & S Long, cold winters w/little precip. 2 Subcategories: – ET – temp moderated by ocean – precip mostly June-Oct.- polar high dominates – EF – interior Greenland and Antarctica – always brutally cold – polar desert

42. Polar Climates (E)

43. ET

44. EF

45. Highland Climates (H) Associated with large mtn ranges, e.g. Andes, Rockies, Alps, etc. Cooler/colder than surrounding lowlands, even in tropical or equatorial regions Often wetter than surroundings due to orographic precip.

46. North American Climates