1. Title Page Photo
“I've lived in good climate, and it bores the hell out of
me. I like weather rather than climate.”
climate.”
—John Steinbeck (Brainquote.com)
(Brainquote.com)
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 Climate Classification
• The Purpose of Classifying Climates
– To understand distribution of climates
– To compare climates of different places
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• The Early Greek Classification Schemes
– Greeks
• Temperature and latitude
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2. – Major climate zones of the Old World, as
recognized today
1) Equatorial warm wet
2) Tropical hot dry
3) Subtropical warm temperate
4) Midlatitude cool temperate
5) High-latitude cold
– Fig. 8-2
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 The Köppen Classification System
• Empirical System
– Has a numerical basis
• Temperature data
• Precipitation data
• Teaching tool
– Simple to comprehend and to use
– Shows an orderly pattern over the world
– Gives some indication of climate origin (genesis)
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• Modified Köppen System
– Five major climate groups
• Groups A, B, C, D, and E
– 14 individual climate types
• Special category of highland (H) climate
– Fig. 8-3 6
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3. – Climatic Regions of the World
• Fig. 8-4 7
 Tropical Humid Climates (Group A)
• Distribution of A Climates
– Within 0–25º of equator
• Fig. 8-6
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• Distinctive Features of A Climates
– Average daily temperature greater than annual
temperature range
• Fig. 8-8
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4. – No true winter
• “Winter” in tropics refers to the “low-sun” half of the year
“Summer” refers to the “high-sun” half of the year
– High temperatures prevail every month
• A climates are distinguished by the monthly pattern of
rainfall
– f = year-around rainfall
– m = year-round rainfall, but with a brief drier period
– w = wet summer and dry winter
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 Tropical Wet Climate (Af)
• Main locations
– Within 5–10º of equator
– Amazon basin
– Northern Congo basin
– Islands of East Indies
• Characteristics
─ Monotonous (“seasonless”)
“Night is the season of the tropics”
─ High humidity
─ Afternoon convective thundershowers
─ High annual rainfall, evenly distributed during year
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• Dominant Controls
– ITCZ influence entire year
NH summer
winter winter
SH summer
wet season
dry season dry season
Trades cT Wet season
Traddes cT
Tra
es Trad e
s Convective
precipitation
10ºN 0º 10ºS
30
N ºS
30º Af
• Animated Drawing (toggle forward-back-forward)
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5. • Climographs
– Fig. 8-7
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 Tropical Savanna (AW)
• Main locations
– 5–25º of latitude
– Most extensive of A climates
– Adjacent to Af climates
– Most widespread in Africa, South America
– South Asia and northern Southeast Asia
– Northern Australia
• Characteristics
• Clear-cut seasonal alternation of wet and dry periods
• Lower precipitation than other A climates
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• Dominant Controls
– ITCZ dominates during summer
– cT or cP air mass dominates during winter
• Fig. 8-11
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6. • Climographs
– Fig. 8-10
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 Tropical Monsoon (AM)
• Main locations
– Coastal regions
– Most prominent area is west-facing coasts of
India, southeastern Asia
– Smaller areas scattered in tropical latitudes
• Characteristics
– Very high rainfall totals in summer
– Brief (1-4 months), drier period in winter
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• Dominant Controls
– ITCZ movement
– Jet Stream fluctuation
– Continental pressure changes
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7. • Climographs
– Fig. 8-12
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 Dry Climates (Group B)
– Fig. 8-14
• Distribution of B Climates
– Subtropical Dry Climates within 20–35º of latitude
– Midlatitude Dry Climates within 35-55º of latitude
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• Distinctive Features of B climates
– Cover 30% of the total land area of the world
• More area than any other climate group
– Dry conditions prevail all year
• Potential evapotranspiration is greater than precipitation
– Two main sub-types based on precipitation
• BW is extremely arid (desert)
• BS is steppe (semi-arid)
– The two sub-types are further subdivided based
on temperature
• h is for the hot subtropical desert (BWh, BSh)
• k is for the cold midlatitude desert (BWk, BSk)
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8.  Subtropical Desert (BWh)
• Main locations
– Centered at latitudes 25–30º
– Western sides of continents,
including coasts
• Extend into continental interiors
– Northern Hemisphere
• Sonora-Colorado
• Sahara
• Arabian
– Southern Hemisphere
• Peru-Atacama
• Kalahari-Namib
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• Characteristics
– Precipitation: extremely arid
• Scarce (most nearly rainless regions on Earth)
• Unreliable (extremely long periods without rain)
• Intense (brief, but heavy convective downpours)
– Very hot summers
– Enormous daily temperature range
– Coastal equatorward extensions: advection fog
off-shore
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• Dominant Controls
– Subsidence from subtropical highs (STHs)
• Fig. 8-15
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9. – Cold ocean currents
• Equatorward extensions
– Fig. 8-17
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• Cool, foggy west coast deserts
– Fig. 8-18
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• Climographs
– Fig. 8-16
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10.  Subtropical Steppe (BSh)
• Main locations
– Fringing BWh except on west coasts
• Characteristics
– Similar to BWh but more moderate
– Precipitation: semiarid
• Dominant Controls
• Similar to BWh
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• Climographs
– Fig. 8-20
(Richard A. Crooker photos)
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 Midlatitude Desert (BWk)
• Main locations
– Central Asia
– Western interior
of United States
– Patagonia
– Fig. 8-14
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11. • Characteristics
– Precipitation meager
• Erratic, mostly showery
• Some winter snow
– Temperatures
• Hot summers, cold winters
• Very large annual temperature range
• Large daily temperature range
• Dominant Controls
– Rain shadow effects
– Distance from sources of moisture
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• Climographs
– Fig. 8-21
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 Midlatitude Steppe (BSk)
• Main locations
– Fringing BWk
• Characteristics
– Similar to BWk
(more moderate)
– Precipitation:
semiarid – Fig. 8-14
• Dominant Controls
– Similar to BWk
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12. • Climographs
Photo: U.S. Great
Plains, South Dakota
– Fig. 8-22
Photograph Sourc e: U.S. Geological Surveyhttp://www.usgs.gov/125/articles/conservation.html 34
 Mild Midlatitude Climates (Group C)
– Fig. 8-23
• Distribution of C Climates
– Equatorward margin of the middle latitudes
– Within 25-40º of latitude with some poleward
extensions
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• Distinctive Features of C climates
– Temperatures
• Long summers, usually hot
• Short winters, relatively mild
– Precipitation
• No year-round moisture deficiency
• Some climates have seasonal shortages
– Three subtypes
• Mediterranean (Csa, Csb)
• Humid subtropical (Cfa)
• Marine west coast (Cfb, Cfc)
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13.  Mediterranean Climates (Csa, Csb)
• Main locations
– Western side of continents
• 30–40º of latitude
– Mediterranean coast
– California
– Central Chile
– Southern tip of Africa (Cape Town)
– Australia (Perth & Adelaide)
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• Characteristics
– Mild, wet winters, dry summers
– Two sub-types based on summer temperatures
• a – hot summer (interior location)
• b – cool/mild summer (coastal location)
• Fig. 8-26
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– Precipitation
• Moderate annually
• Winter maximum (midlatitude cyclonic storms)
• Dominant Controls
– STH subsidence in summer (forces cyclonic
storms poleward)
– Westerly winds and cyclonic storms shift
equatorward in winter
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14. • Climographs
– Fig. 8-24
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 Humid Subtropical (Cfa, Cwa)
• Main locations
– Eastern sides of continents
• 25–30º of latitude
– Southeastern United States
– Eastern China
– Southern Brazil and Uruguay
– Small areas in Africa and Australia
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• Characteristics
– Temperatures
• Summers, warm to hot
• Winters, mild to cold
– Precipitation
• Abundant, mostly as rain
• Summer maximum
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15. • Climographs
– Fig. 8-27
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 Marine West Coast
• Main locations
– Western sides of continents, mainly
• 40–65º
– Western and central Europe
• Largest area
– North America
• Oregon to Alaska
– New Zealand and eastern Australia
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• Characteristics
– Temperature
• Very mild winters for latitude
– Precipitation
• Moderate to abundant, mostly in winter
• Many rainy days
• Much cloudiness
• Dominant Controls
– Westerly flow and oceanic influence year-round
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16. • Climographs
– Fig. 8-30
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 Severe Midlatitude Climates (Group D)
– Fig. 8-31
• Distribution of D Climates
– Only in Northern Hemisphere
– Within 35–70º of latitude
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• Distinctive Features of D climates
– Temperatures
• Large annual temperature range
– Continentality
• Cold winter, relatively short summer
– Precipitation
• Summer maxima
• Abundant to meager amounts
• Diminishes toward inland and poleward
– Two Main Subtypes
• Humid Continental
• Subarctic
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17.  Humid Continental (Dfa, Dfb, Dwa, Dwb)
• Location
– N. Hemisphere only
– 35–55º of latitude
– Eastern sides of continents
– Fig. 8-31
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• Characteristics
– Temperature
• Warm/hot summers
• Large annual temperature range
– Precipitation
• Moderate to abundant
• Summer maxima
• Dominant Controls
– Westerly winds and storms
• Midlatitude cyclones in winter in North America
• Monsoons in Asia
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• Climographs
– Fig. 8-32
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18.  Sub Arctic (Dfc, Dfd, Dwc, Dwd)
• Location
– Northern Hemisphere only
– Latitudes 50–70º
– Across North American and Eurasia
• Characteristics
– Temperature
• Long, dark, very cold winters
• Brief, mild summers
• Enormous annual temperature range
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– Precipitation
• Meager
• Summer maxima
• Light snow in winter, little melting
• Dominant Controls
– Pronounced continentality
– Alternating…
• Westerlies and cyclonic storms
• Prominent anticylcones
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• Climographs
– Fig. 8-35
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19.  Polar Climates (Group E)
• Distribution of E Climates
– Poleward of 70º of latitude
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• Distinctive Characteristics
– Temperatures
• Coldest summers
• Lowest annual average
• Large annual temperature range
• Small daily temperature range
– Extraordinarily dry
• Low precipitating, mostly snow
• Evaporation is nil
– Two subtypes
• Tundra
• Ice Cap
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 Tundra (ET)
• Main Locations
– Fringes of Arctic Ocean
– Small coastal areas in Antarctica
• Fig. 8-36
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20. • Characteristics
– Temperature
• Long, cold dark winters
• Brief, cool summers
– Precipitation
• Very sparse
• Mostly snow
• Dominant Controls
– Latitude
– Distance from sources of heat and moisture
– Extreme seasonal contrasts in sunlight/darkness
– Polar anticyclones (A and cP air masses)
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• Climographs
– Fig. 8-37
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 Ice Cape (EF)
• Location
– Antarctica
– Greenland
• Characteristics
– Temperature
• Long, cold, dark
winters
• Cold, windy
summers
– Precipitation
• Very sparse, all
snow
• Fig. 8-36
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21. • Dominant Controls
– Latitude
– Distances from sources of heat and moisture
– Extreme seasonal contrasts in sunlight/darkness
– Polar anticyclones (A and cP air masses)
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• Climographs
– Fig. 8-38
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 Highland Climate (Group H)
• Locations
– High uplands (mountains and plateaus)
– Fig. 8-40
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22. • Characteristics
– Complex local variation in small areas
– Vertical climate zonation
– Fig. 8-42
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– Changeability of weather
– Fig. 8-43
• Dominant Controls
– Altitude
– Slope aspect and slope angle
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• Climographs
– Fig. 8-41
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23.  Global Patterns Idealized
• General Models of the Climate Distribution
– Idealized seasonal
precipitation patterns
and climates along the
west coasts of
continents (Fig. 8-44).
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– Idealized Global Pattern
– Fig. 8-45
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• Climatic Distribution in Africa: A Practically
Perfect Example
– Fig. 8-45 and Fig. 8-46
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24. • The modified Köppen system recognizes six
major climatic zones:
1. Tropical humid (A)
2. Dry (B)
3. Mild midlatitude (C)
4. Severe midlatitude (D)
5. Polar (E)
6. Highland (H)
• A model of climate distribution on a
hypothetical continent helps use predict what
the climate should be like at a particular
location.
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