Atmospheric Circulation Patterns

Atmospheric Circulation

• Global Wind Patterns:
  • Trade winds: blow from high to low pressure near the equator
  • Wasterlies: blow from high to low pressure in mid-latitudes
  • Jet stream: fast-moving wind current in the upper atmosphere
• Global Pressure Belts:
  • High-pressure belts near 30°N and 30°S latitude
  • Low-pressure belts near the equator and 60°N and 60°S latitude
• Cellular Circulation:
  • Hadley cells: near the equator, warm air rises, cools, and sinks
  • Ferrel cells: in mid-latitudes, air sinks, warms, and rises
  • Polar cells: near the poles, cold air sinks, warms, and rises

Climate Zones

• Tropical Climate Zone:
  • High temperatures and high humidity near the equator
  • Little seasonal variation in temperature
• Temperate Climate Zone:
  • Moderate temperatures and rainfall in mid-latitudes
  • Distinct seasonal variations
• Polar Climate Zone:
  • Extremely cold temperatures and low humidity near the poles
  • Limited seasonal variation

Weather Forecasting

• Observation:
  • Surface weather stations: measure temperature, humidity, wind, and pressure
  • Radar: uses radio waves to detect precipitation
  • Satellites: observe cloud patterns and atmospheric conditions from space
• Numerical Weather Prediction (NWP):
  • Uses computer models to forecast weather patterns
  • Solves equations governing atmospheric behavior
• Nowcasting:
  • Uses current weather conditions to predict immediate future weather
  • Focuses on short-term, local forecasts

Natural Disasters

• Types of Disasters:
  • Hurricanes/Typhoons: intense tropical cyclones
  • Tornadoes: rotating columns of air that touch the ground
  • Floods: excessive water in a normally dry area
  • Droughts: prolonged periods of abnormally low rainfall
• Causes and Effects:
  • Natural factors: weather patterns, climate change, and geological processes
  • Human factors: deforestation, urbanization, and climate change
  • Impacts: loss of life, property damage, and environmental degradation

Atmospheric Circulation

• Global Wind Patterns:
  • Trade winds blow from high to low pressure near the equator, resulting in a northeast direction in the Northern Hemisphere and a southeast direction in the Southern Hemisphere.
  • Wasterlies blow from high to low pressure in mid-latitudes, resulting in a southwest direction in the Northern Hemisphere and a northwest direction in the Southern Hemisphere.
  • The jet stream is a fast-moving wind current in the upper atmosphere, playing a crucial role in shaping global weather patterns.
• Global Pressure Belts:
  • High-pressure belts form near 30°N and 30°S latitude due to the sinking of air, resulting in clear skies and fair weather.
  • Low-pressure belts form near the equator and 60°N and 60°S latitude due to the rising of air, resulting in cloudy skies and precipitation.
• Cellular Circulation:
  • Hadley cells near the equator: warm air rises, cools, and sinks, creating a circulation pattern that drives the trade winds.
  • Ferrel cells in mid-latitudes: air sinks, warms, and rises, creating a circulation pattern that drives the wasterlies.
  • Polar cells near the poles: cold air sinks, warms, and rises, creating a circulation pattern that drives the polar easterlies.

Climate Zones

• Tropical Climate Zone:
  • High temperatures and high humidity near the equator, resulting in a relatively constant temperature throughout the year.
  • Little seasonal variation in temperature, with minimal changes in temperature between summer and winter.
• Temperate Climate Zone:
  • Moderate temperatures and rainfall in mid-latitudes, resulting in a distinct seasonal variation.
  • Distinct seasonal variations, with warm summers and cold winters.
• Polar Climate Zone:
  • Extremely cold temperatures and low humidity near the poles, resulting in a harsh climate.
  • Limited seasonal variation, with long, cold winters and short, cool summers.

Weather Forecasting

• Observation:
  • Surface weather stations measure temperature, humidity, wind, and pressure to provide accurate weather data.
  • Radar uses radio waves to detect precipitation, allowing for accurate forecasting of rain and storms.
  • Satellites observe cloud patterns and atmospheric conditions from space, providing a global view of weather patterns.
• Numerical Weather Prediction (NWP):
  • Uses computer models to forecast weather patterns by solving equations governing atmospheric behavior.
  • Computer models consider atmospheric conditions, wind patterns, and other factors to predict future weather.
• Nowcasting:
  • Uses current weather conditions to predict immediate future weather, focusing on short-term, local forecasts.
  • Nowcasting is essential for predicting severe weather events, such as tornadoes and hurricanes.

Natural Disasters

• Types of Disasters:
  • Hurricanes/Typhoons: intense tropical cyclones with strong winds and heavy rainfall.
  • Tornadoes: rotating columns of air that touch the ground, causing damage and destruction.
  • Floods: excessive water in a normally dry area, resulting from heavy rainfall, storm surge, or dam failure.
  • Droughts: prolonged periods of abnormally low rainfall, resulting in water scarcity and crop failure.
• Causes and Effects:
  • Natural factors: weather patterns, climate change, and geological processes contribute to the occurrence of natural disasters.
  • Human factors: deforestation, urbanization, and climate change can exacerbate the impact of natural disasters.
  • Impacts: loss of life, property damage, and environmental degradation are the devastating consequences of natural disasters.