Lecture Notes: The Power of Air and Meteorological Phenomena

Introduction

• Air, though seemingly powerless, significantly influences weather and natural phenomena.
• Meteorological phenomena like snow, rain, and wind are influenced by air pressure.

Air Masses

• Air Mass: Large body of air with uniform temperature and humidity.
• Temperature influenced by latitude:
  • Low latitudes: Close to the Equator, warm/hot air masses.
  • High latitudes: Cold air masses.
• Humidity influenced by formation location:
  • Sea: Humid air masses.
  • Land: Dry air masses.

Air Masses Affecting Korea

1. Siberian Express
   • Origin: Siberia
   • Weather Influence: Cold and dry winters in Korea.
2. Northern Pacific High
   • Origin: Ocean, south of Japan
   • Weather Influence: Hot and humid summers in Korea, causing rainy season.
3. Okhotsk High
   • Origin: Sea of Okhotsk
   • Weather Influence: Cold, humid; affects Korea with Foehn effect winds.
4. Yangtze River Air Mass
   • Origin: Mainland China
   • Weather Influence: Warm and dry, causes Yellow Dust and cold spells in spring and fall.

Fronts

• Front: Boundary where two different air masses meet the ground.
• Types of Fronts:
  1. Cold Fronts: Quick movement, leads to showers and drop in temperature.
  2. Warm Fronts: Slow movement, results in light rain and rise in temperature.
  3. Occluded Fronts: Formed when fast-moving cold front overtakes a warm front.
  4. Stationary Fronts: Little to no movement, prolonged weather pattern.

Air Pressure Zones

• High Pressure Zones:
  • Clear weather due to descending air currents.
  • Types:
    • Stationary (e.g., Siberian and North Pacific zones).
    • Migratory (move with westerly winds).
• Low Pressure Zones:
  • Cloudy, rainy or snowy weather from rising moist air.
  • Types:
    • Temperate (e.g., cold fronts at 60° latitude).
    • Tropical (e.g., typhoons, hurricanes).

Typhoons

• Typhoons: Tropical depressions with wind speeds ≥ 17 m/s.
• Characteristics:
  • Diameters: 200 km to 1,500 km.
  • Height: 15 km.
  • Move from NW to NE upon meeting westerly winds.
  • Die out due to cooler waters or landfall.
• Typhoon Surge: Sea level rise (1 cm per 1hPa air pressure drop), intensified during high tide.

Conclusion

• Air powerfully affects everyday weather and natural disasters.
• Upcoming topic: Global atmospheric circulation.