World Climate Regimes Geog403

Climate classifications Empirical Classification: based on the results (temperature, precipitation, vegetation, etc.) Examples: Köppen’s classification; Thornthwaite’s classification Genetic Classification: based on the causes (air masses, atmospheric circulation; geographical location, etc.) Examples: Strahler and Strahler; Mather

Köppen Climate Classification (based on vegetation distribution) A: Equatorial (tropical) Climate Af-humid, no dry season (tropical rainforest) Am- short dry season (monsoon) Aw-wet and dry seasons (Savanna)

Rainforest

Monson

Tropical Savanna

Koppen- Desert B: Dry climate Bs: semiarid Bw: arid

Low-Latitude Hot Desert

Mid-Latitude Cold Desert

Low-Latitude Hot Steppe

Köppen- Mesothermal C: Humid Temperate climate Cf-no dry season Cw-dry winter (subtropical monsoon; interior) Cs-dry summer (mediterranean)

Humid Subtropical Hot-Summer

Humid Subtropical Winter-Dry Figure 10.12

Marine West Coast

Mediterranean Climates

KÖppen-Microthermal D: Humid Cold Climate Df-no dry season Dw-dry winter (interior, high latitude, shorter, cooler summer)

Humid Continental Hot-Summer Climates

Humid Continental Mild-Summer Climates

Subarctic Cool Summer Climates

Extreme Subarctic Cold Winter

Polar and Highland climates E: Cold polar climate (too cold to support vegetation) F: High Land climate

Genetic classification Air masses: cP: continental polar (cold and dry; source: northern Canada, Siberia) mP: maritime polar (cool and moist; Source: northern Pacific and Atlantic Ocean) cT: continental tropical (hot and dry; source: desert) mT: maritime tropical (warm and moist; tropical oceans) mT cT cP mP

General Circulation patterns ITCZ: inter-tropical convergence zone (wet) NE trade wind Subtropical high (dry) Westerlies Polar front (wet) NE wind

Potential evapotranspiration Defined by Thornwaite The demand of water by a continuous vegetation cover with uniform height that never lacks of water It is determined by the latitude (solar radiation) and time of the year (solar angle) only. (or represents the air temperature)

Genetic Climate regimes Low latitudes (30ºS-30ºN) 1. Wet equatorial 10ºS-10ºN, warm to hot, abundant rain. 2. Tropical wet and dry: 5º-25º N or S, warm to hot, distinct wet and dry seasons (savanna) 3. Trade wind littoral (monsoon and trade wind), east coast 10º-25º N or S. 4. Tropical desert/steppe: 15º-35ºN or S, world’s hottest desert 5. West coast desert: 15º-30ºN or S, west coast. PE P JD P P J 1 & & 5

Middle latitudes (30º-60ºN or S) 6. Humid subtropical: 25º-40ºN or S eastern continent, hot and humid summer, mild winters, ample rain year around. 7. Mediterranean: 30º-40ºN or S west coast, hot and dry summer, and rainy winters 8. Maritime west coat (40º-60ºN or S), warm summers and cool winters with more rain in winter. 9. Middle-latitude desert and steppe: 35º-60ºN or S interior, not as hot and dry. 10. Humid continental: 35º-60ºN or S, cold winters and warm summers, ample precipitation through out the year. P PE P P P 9 P 10

High latitudes (60º-90ºN) Continental subarctic: 50º-70ºN interior, short, cool summers and long bitterly cold winters. Marine subarctic: 50º-60º west coast, cool summers, mild winters. Tundra: 50ºN, long severe winters (proximity to Arctic ocean). Ice cap: bitterly cold temperatures, temperature remains below freezing in summer.

60N 30N Tropical wet West Coat Desert Tropical wet & dry Desert and Steppe Trade wind littoral Mediterranean Humid tropical Desert Humid continental Marine west coast Marine subarctic Continental subarctic Tundra Ice cap 0N 90N