Meteorology Class 16: Climatology

Introduction to Climatology

• Climatology: Study of why weather patterns are the way they are in various geographic locations.
• Focus on typical climates around the world.

Key Concepts

Air Movement and Hadley Cells

• Hadley Cells: Drive predictable weather patterns and climate.
• Surface Heating at Equator: Causes air to rise → Low pressure.
• Tropopause: Air spreads out, cools, descends in subtropical regions → High pressure.
• Poles: Surface cooling creates high pressure, pulling air from mid-latitudes.
• Geographical Impact: 3 Hadley cells per hemisphere.

Winds

• High to Low Pressure: Air flows from high to low pressure and feels effects of the geostrophic/Coriolis force.
• Trade Winds: Air flowing towards the equator from subtropical highs; deflected by Coriolis force (right in N. Hemisphere, left in S. Hemisphere).
• Inter-Tropical Convergence Zone (ITCZ): Convergence of trade winds; fluctuates with seasons.
• Mid-Latitudes Winds: Generally westerly due to Coriolis effect.
• Southern Ocean Winds: High-speed winds due to lack of land.

Climate Zones by Latitude

Equatorial/Tropical Zone

• Rainforest: Near equator, high precipitation, convective weather year-round.
• Savannah: Slightly cooler, distinct dry and wet seasons.

Arid/Dry Zone

• Desert: High daily temperature variation, low precipitation.
• Steppe: Slightly more precipitation than deserts.

Temperate Zone

• Cool: High seasonal variation, four distinct seasons (Winter, Spring, Summer, Autumn).
• Warm/Mediterranean: Hot dry summers, warm wet winters, moderate seasonal variation.

Snow/Sub-Arctic Zone

• Regions: Predominantly Russia and Canada.
• Characteristics: Large seasonal variation due to vast land, hot summers, long cold winters.

Polar Zone

• Characteristics: Extreme seasonal variations, very cold winters, continuous daylight in summer and night in winter.

Local and Seasonal Factors

Monsoon

• Mechanism: Surface heating differences between land and ocean cause seasonal winds.
• Summer: Low pressure on land, moist air flows inland → Heavy precipitation.
• Winter: High pressure on land, dry air flows to the ocean.
• Regions: India, North Australia, West Africa, East Asia.

Local Winds

• Shirocco: Hot, dry wind from the Sahara.
• Mistral: Northerly breeze down the Rhone Valley.
• Bora: Katabatic wind over Balkan mountains.
• Foehn Winds: Warm wind formed by adiabatic warming after crossing a mountain peak.

Summary

• Hadley Cells: Low pressure at equator, high pressure in subtropical, reversed at poles.
• Trade Winds: Created by Coriolis force, affect climate patterns.
• Climate Zones: Defined by latitude:
  • Equatorial: Rainforest, Savannah
  • Arid: Desert, Steppe
  • Temperate: Cool, Warm
  • Sub-Arctic: Large land masses, high variation
  • Polar: Extreme variations
• Monsoon and Local Winds: Impact local climates and weather patterns.