Climate Controls and Classifications Lecture

Overview

• Discussion on climate controls forming different climate classes.
• Focus on the climates of the Northern Hemisphere, particularly extra-tropical climates.

Extra-Tropical Climates

• Northern Hemisphere

  • Diverse climates from tropics poleward.
  • Influenced by local factors (e.g., lakes, topography changes in North America).
  • Europe: More poleward latitudes, significant land mass into Russia, extreme pressure cells.
  • Asia: Extreme topography, monsoonal flows.

• Southern Hemisphere

  • Includes Oceania and Antarctica.
  • Oceania: Australia, New Zealand, Indonesia, small island nations.
  • South America and Africa predominantly tropical.
  • Water significantly influences oceanic climates.
  • Australia: Predominantly dry (B climates) with coastal moist flow (C climates).
  • Influenced by El Niño Southern Oscillation.
  • Antarctica: Extreme climates due to lack of insulation.

Desert Climates

• Defined by less than 10 inches of precipitation annually.
• Variable precipitation, can occur in hot and cold regions.
• Antarctica as an example of a cold desert.

Desert Formation Controls

• Lack of storm activity, descending air under high pressure.
• Types of deserts:
  • Rain Shadow Deserts: Leeward side of mountains.
  • Continental Deserts: Far from moisture sources.
  • Coastal Deserts: Influenced by cold ocean currents.

Sea Climates (C Climates)

• Modified by water, found under on-land flow influence.
• Located near warm ocean currents or subtropical high pressure cells.
• Associated with mid-latitude cyclones in North America and Australia.
• Characteristics:
  • Moderate climates with even precipitation distribution.
  • Rare freezing days, occasional snow events can disrupt urban areas.

D Climates

• Location: Poleward of C climates, found only in Northern Hemisphere.
• Characteristics:
  • Receive less radiation, lower sun angles.
  • Continentality influences greater temperature ranges.
  • Even precipitation distribution, slight summer increase.
  • Includes sub-Arctic climates with boreal forests.

E Climates

• Influenced by latitude and water.
• Characteristics:
  • High altitudes, low sun angles, variable day lengths.
  • Extremely low winter temperatures, high albedo in snow-covered areas.
  • Low precipitation, resembling cold deserts.
  • Limited heat transfer from ocean due to sea ice in winter.