meterology

• High-Level Clouds:

  • Cirrus Clouds (Ci):
  • Altitude: Above 20,000 feet
  • Appearance: Wispy, feathery clouds
  • Significance: Indicate fair weather but can signal approaching changes
  • Cirrostratus Clouds (Cs):
  • Altitude: Above 20,000 feet
  • Appearance: Thin, ice-crystal clouds covering the sky
  • Significance: Often precede storms, causing halos around the sun or moon
  • Cirrocumulus Clouds (Cc):
  • Altitude: Above 20,000 feet
  • Appearance: Small, white patches of clouds
  • Significance: Indicate atmospheric instability; may precede or accompany storms
• Middle-Level Clouds:

  • Altostratus Clouds (As):
  • Altitude: 6,500 to 20,000 feet
  • Appearance: Gray or blue-gray cloud covering the sky
  • Significance: May cover the entire sky, often preceding storms with continuous rain or snow
  • Altocumulus Clouds (Ac):
  • Altitude: 6,500 to 20,000 feet
  • Appearance: White or gray clouds, usually forming a layer
  • Significance: May indicate a change in the weather with possible precipitation
• Low-Level Clouds:

  • Stratus Clouds (St):
  • Altitude: Surface to 6,500 feet
  • Appearance: Gray, overcast clouds covering the sky
  • Significance: Often associated with overcast weather, light mist, and drizzle
  • Stratocumulus Clouds (Sc):
  • Altitude: Surface to 6,500 feet
  • Appearance: Low, lumpy clouds covering the sky
  • Significance: May bring light rain or drizzle
  • Nimbostratus Clouds (Ns):
  • Altitude: Surface to 6,500 feet
  • Appearance: Thick, dark clouds covering the sky
  • Significance: Associated with continuous, steady precipitation
• Vertical Development Clouds:

  • Cumulus Clouds (Cu):
  • Altitude: Surface to 20,000 feet
  • Appearance: White, fluffy clouds with a flat base
  • Significance: Often associated with fair weather but can develop into larger storm clouds
  • Cumulonimbus Clouds (Cb):
  • Altitude: Surface to 50,000 feet or higher
  • Appearance: Towering clouds with an anvil-shaped top
  • Significance: Associated with severe weather, including thunderstorms, hail, and tornadoes
• Special Clouds:

  • Lenticular Clouds:
  • Altitude: Varies
  • Appearance: Lens-shaped clouds often forming over mountains
  • Significance: Indicate strong winds and turbulence in the area
• Composition and Physical Properties:

  • Major Components: Nitrogen (78%), Oxygen (21%), Argon (0.93%)
  • Minor Components: Carbon Dioxide, Water Vapor, Trace Gases
• Vertical Structure:

  • Troposphere: Weather occurs, temperature decreases with altitude
  • Stratosphere: Temperature increases due to ozone layer
  • Mesosphere: Temperature decreases again
  • Thermosphere: High temperatures due to solar activity
• Standard Atmosphere:

  • International Standard Atmosphere (ISA) provides a model for atmospheric conditions
  • Standard temperature lapse rate: 2°C per 1,000 feet
• Density and Pressure:

  • Density decreases with altitude and influences aircraft performance
  • Pressure decreases with altitude and is measured using an altimeter
• Mobility:

  • Air molecules move freely, leading to atmospheric mobility
  • Influences weather patterns and air circulation
• Expansion and Compression:

  • Air expands and cools when ascending, compresses and warms when descending
  • Key factors in weather phenomena
• Atmospheric Pressure:

  • Measured using barometers and altimeters
  • Units: Inches of Mercury (inHg) or Hectopascals (hPa)
• Pressure Systems and their Variations:

  • High-pressure systems: Anticyclones, associated with fair weather
  • Low-pressure systems: Cyclones, associated with stormy weather
• Effects of Temperature:

  • Temperature influences pressure readings
  • Warm air results in lower pressure; cold air results in higher pressure
• Isobars:

  • Lines connecting points of equal pressure on weather maps
  • Closely spaced isobars indicate strong pressure gradients
• Horizontal Pressure Differences:

  • Horizontal pressure differences influence wind patterns
  • Winds flow from high to low-pressure areas
• Meteorological Aspects of Altimetry:

  • Pressure Altitude: Altitude read directly from the altimeter
  • Density Altitude: Pressure altitude corrected for non-standard temperature
  • Altimeter Settings: Set to local pressure to provide accurate altitude indications
• Stability and Instability:

  • Lapse Rate and Stability
  • Modification of Stability
  • Characteristics of Stable / Unstable Air
• Turbulence:

  • Convection -Turbulence caused by rising and falling air currents.
  • Mechanical -Turbulence due to wind passing over or around obstacles.
  • Orographic -Turbulence caused by air flowing over mountains.
  • Wind Shear -Rapid change in wind direction or speed with altitude.
• Cloud formations caused by air mass lifting, Occurs when air reaches its dewpoint
• • Stable air resists vertical motion; unstable air encourages vertical motion.
• Relative humidity: Percentage of moisture in the air relative to saturation.
• • Dewpoint: Temperature at which air becomes saturated.
• • Sublimation: Transition from solid to gas.
  • Condensation: Gas to liquid.
  • Evaporation: Liquid to gas.