Chapter 7 Global Climates Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Chapter Overview Keys to Climate Climate Classification Low-Latitude climates (Group I) Midlatitude Climates (Group II) High-Latitude Climates (Group III) Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Describe how temperature and precipitation affect climate. Objectives Describe how temperature and precipitation affect climate. Explain how climographs are related to climate groups. Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Describe the features of low, mid, and high-latitude climates. Objectives Describe the features of low, mid, and high-latitude climates. Discuss the climate groups found in low, mid, and high-latitude climates Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

What determines temperature? Keys to Climate Temperature Regimes Climate: the annual cycle of prevailing weather conditions at a given place, based on statistics taken over a long period What determines temperature? 1. LatitudeVariation in insolationTemperature 2. Location—maritime or continental—moderates that variation Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Keys to Climate Global precipitation regions: 1. Wet equatorial belt 2. Trade-wind coasts 3. Tropical deserts and steppes 4. Midlatitude deserts 5. Moist subtropical regions 6. Midlatitude west coasts 7. Arctic and polar deserts Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Seasonal precipitation patterns: Uniformly distributed Keys to Climate Global Precipitation Seasonal precipitation patterns: Uniformly distributed Summer precipitation maximum Winter precipitation maximum Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Climate Classification Air Mass Source Regions Group I: Low-Latitude Climates Group II: Midlatitude Climates Group III: High-Latitude Climates Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Climate Classification Dry and Moist Climates Dry Climates: total annual evaporation>annual precipitation Semiarid (steppe) Arid Moist Climates: enough rain to keep soil moist all year, sustain year- round flow of larger streams Support forests or prairies Wet-dry Climates: alternate wet and dry seasons Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Climate Classification Highland Climates Usually cool Temperatures decrease with altitude Usually Moist Orographic precipitation Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Climate Classification Climograph: graph on which two or more climate variables are plotted for each month of the year Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Climate Classification Seasonal Precipitation Patterns Equatorial regions: wet all year Trade winds bring rain to equatorial/tropical east coasts Tropical deserts underlie subtropical high pressure cells Eastern sides of midlatitude continents: warm moist air from western sides of subtropical highs Midlatitude west coasts: subtropical highs block rainfall in summer Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Climate Classification Temperature Patterns Latitude: temperatures drop from equator to poles Location: continental interiors have greater range in temperature than coastal regions Elevation: temperatures drop with elevation Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Low-Latitude climates (Group I) Four low-latitude climates: Wet equatorial 2. Monsoon and trade-wind coastal 3. Wet-dry tropical 4. Dry tropical Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Low-Latitude climates (Group I) 1.Wet Equatorial Climate: moist climate of the equatorial zone with a large annual water surplus and uniformly warm temperatures through the year Controlled by ITCZ Warm, moist mE and mT air masses Heavy convectional rainfall Uniform temperatures through the year Low-latitude rainforests Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Low-Latitude climates (Group I) 2. Monsoon and trade-wind coastal climate: moist climate of low latitudes showing a strong rainfall peak in summer and short period of reduced rainfall in low-sun season Abundant rainfall Strong seasonal pattern Monsoon winds bring moist air to west coasts Trade winds bring moist air to east coasts Low-latitude rainforests Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Low-Latitude climates (Group I) 3. Wet-dry tropical climate: climate of the tropical zone characterized by a very wet season alternating with a very dry season Very dry season at low sun ITCZ is far away Very wet season at high sun ITCZ is nearby Savanna vegetation Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Low-Latitude climates (Group I) 4. Dry Tropical Climate: climate of the tropical zone with high temperatures and low rainfall. Center and east sides of subtropical high pressure cells Extreme heat, large daily temperature range Generally between 15º and 25º N and S Arid deserts and semiarid steppes Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Midlatitude Climates (Group II) Six midlatitude climates: 5. Dry Subtropical 6. Moist Subtropical 7. Mediterranean 8. Marine West-coast 9. Dry midlatitude 10. Moist Continental Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Midlatitude Climates (Group II) 5. Dry Subtropical Climate: dry climate of the subtropical zone, transitional between the dry tropical climate and the dry midlatitude climate Poleward extension of dry tropical climate High annual temperature range Arid and semiarid subtypes Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Midlatitude Climates (Group II) 6. Moist Subtropical Climate: moist climate of the subtropical zone, characterized by a moderate to large annual water surplus and a strong seasonal temperature cycle Eastern sides of continents, between 20º and 35º N and S mT air from western side of subtropical high pressure cells Warm humid summers, abundant rainfall Mild winters, ample rainfall Forest vegetation Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Midlatitude Climates (Group II) 7. Mediterranean Climate: climate type of the subtropical zone, characterized by the alternation of a very dry summer and a mild, rainy winter Wet winter, dry summer West coast of continents Located between 30º and 45º N and S Vegetation: shrubs and trees with hard leaves to resist water loss (sclerophylls) Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Midlatitude Climates (Group II) 8. Marine West-Coast Climate: Cool, moist climate of west coasts in the midlatitude zone, usually with abundant precipitation and a distinct winter precipitation maximum Abundant precipitation, winter maximum Frequent cyclonic storms Mild winters, low annual temperature range West coasts, between 35º and 60º N and S Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Midlatitude Climates (Group II) 9. Dry Midlatitude Climate: dry climate of the midlatitude zone with a strong annual temperature cycle and cold winters Interior of North America and Eurasia Within the rainshadow of mountain ranges Large annual temperature range Arid and semiarid, desert and steppe Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Midlatitude Climates (Group II) 10. Moist Continental Climate: moist climate of midlatitude zone with strongly defined winter and summer seasons and adequate precipitation throughout the year Cold winters, warm summers Located in the polar-front zone Ample precipitation Forests and tall grasslands Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

High-Latitude Climates (Group III) Three high-latitude climates: 11. Boreal Forest 12. Tundra 13. Ice Sheet Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

High-Latitude Climates (Group III) 11. Boreal Forest Climate: Cold climate of the subarctic zone in the northern hemisphere with long, extremely severe winters and several consecutive months of frozen ground Long cold winters, short, cool summers Source region for cP air masses Greatest range of temperature Boreal forests--needeleaf Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

High-Latitude Climates (Group III) 12. Tundra Climate: Cold climate of the arctic zone with eight or more months of frozen ground Polar and arctic air masses Permafrost below surface Saturated soil in summer Tundra vegetation—low herbs and shrubs Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

High-Latitude Climates (Group III) 13. Ice sheet climate: Severely cold climate found on the Greenland and Antarctic ice sheets Arctic and Antarctic air masses Mean temperature below freezing all months Low precipitation, high winds Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.