Chapter_13_audio

Climate Classification Overview

• The climate classification system is based on mean monthly and annual temperature and precipitation data.
• Data used does not rely on humidity, wind speed, or pressure, making it widely applicable across various weather stations.
• The major climate types include:
  • A type: Tropical climates
  • B type: Dry or semi-arid climates
  • C type: Mesothermal climates (middle latitude)
  • D type: Microthermal climates (cold climates)
  • E type: Polar climates
  • H type: Highland climates (not officially part of original classification)

A Type Climates - Tropical Climates

• Shown in orange on climate maps.
• Found between 30° N to 30° S latitude.
• Characteristics:
  • Hot and consistently warm temperatures throughout the year.
  • Wet year-round in some areas; some exhibit seasonal wetness.
  • Types:
    • Tropical rainforest
    • Monsoon
    • Tropical savanna

B Type Climates - Dry Climates

• Represented in light yellow.
• Includes hot deserts and cold deserts (defined based on precipitation rather than temperature).
• Main criteria:
  • Receives an average of less than 76 cm of precipitation per year.
  • Cold deserts: Mean temperature below 10°C at times.
• Subtypes based on moisture availability:
  • BW: Semi-arid
  • BS: True arid desert

C Type Climates - Mesothermal Climates

• Middle latitude climates that receive adequate rainfall.
• Found between 30° and 60° latitude; includes Mediterranean-type climates.
• Characteristics:
  • Humid subtropical, characterized by hot summers and cool, dry winters.
  • Generally experience a seasonal climate cycle.

D Type Climates - Microthermal Climates

• Primarily found only in the Northern Hemisphere.
• Defined by:
  • Cold temperatures; certain months experience a mean temperature below 10°C.
  • Subcategories:
    • Df: No dry season
    • Dw: Dry winters
    • Seasonal variations in temperature.

E Type Climates - Polar Climates

• Found predominantly above 80° N and S latitude; includes Antarctica and parts of the Arctic.
• Main subtypes:
  • Polar tundra: No month above 10°C.
  • Polar ice cap: All months below 0°C.

H Type Climates - Highland Climates

• Not part of the original classification but important due to altitude effects.
• Defined by:
  • Occur at any latitude; generally above 4,000 meters (13,123 ft).
  • Climate types can resemble polar climates but are linked to elevation rather than geographical latitude.

Letter Designations in Climate Classification

• Primary climate types categorized by a letter (A, B, C, D, E).
• Secondary designations (when applicable):
  • Precipitation patterns (i.e., dry in winter - W, dry in summer - S).
  • Third letter designation often reflects temperature characteristics (i.e., warm versus cold summer).
• Example transitions based on temperature and precipitation:
  • DFB (warm summer, no dry season)
  • DFC (cool summer, no dry season)
  • DWD (dry winter, warm summer)

Climate Data Analysis

• Use empirical data for classification.
• The World Meteorological Organization and Environment Canada provide data for climate normals.
• Important to analyze both temperature and precipitation over a standard period (typically 30 years) to ascertain climate classifications.