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Climatic Zones & TypesClimatic Zones & Types
Part IIPart II
I've lived in good climate, and it bores the hell I've lived in good climate, and it bores the hell
out of me. I like weather rather than climate.out of me. I like weather rather than climate.
——John SteinbeckJohn Steinbeck
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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)
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Dominant Controls
– STH subsidence in summer (forces cyclonic
storms pole-ward)
– Westerly winds and cyclonic storms shift
equator-ward in winter
– Precipitation
• Moderate annually
• Winter maximum (midlatitude cyclonic storms)
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Climographs
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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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Climographs
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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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Climographs
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Severe Midlatitude Climates (Group D)
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 pole-ward
– Two Main Subtypes
• Humid Continental
• Subarctic
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Humid Continental (Dfa, Dfb, Dwa, Dwb) Location
– N. Hemisphere only
– 35–55º of latitude
– Eastern sides of continents
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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
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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
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Polar Climates (Group E)
Distribution of E Climates
– Pole-ward 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
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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
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Ice Cape (EF) Location
– Antarctica
– Greenland
Characteristics
– Temperature
• Long, cold, dark winters
• Cold, windy summers
– Precipitation
Very sparse, all snow
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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
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Highland Climate (Group H)
Locations High uplands (mountains and plateaus)
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Characteristics – Complex local variation in small areas
– Vertical climate zonation
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Changeability of weather
Dominant Controls
– Altitude
– Slope aspect and slope angle
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Climographs
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Global Patterns Idealized
General Models of Climate Distribution
• Idealized seasonal
precipitation patterns and
climates along the west
coasts of continents.
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Idealized Global Pattern
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Climatic Distribution in Africa:
A Practically Perfect Example
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Global Climate Change
• Time scale of observations determine what
patterns of change stand out in the record
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Determining Climates of the Past
Animation (End of the Last Ice Age)
– Dendrochronology
– Oxygen isotope analysis of oceanic sediments
– Ice cores
– Pollen analysis
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Causes of Long-Term Climate Change
Animation (Orbital Variations and Climate Change)
– Volcanic activity and meteor impacts
– Fluctuations in orbital output
– Variations in Earth-Sun relations
– Greenhouse gas concentrations
– Feedback mechanisms
– The roles of the ocean
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Climate Models
– Climate prediction
– Global Circulation Models (GCMs)
• Mathematical models of Earth’s climate system
• Computer simulation models of future climates (3)
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• The fundamental geographic aspect of
climate is its global distribution.
• The modified Köppen classification system
is widely used for its pedagogic value.
• The basis of the Köppen system is
temperatures and precipitation amounts and
patterns.
Summary
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• 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 us predict what the climate should be like at a particular location.
