Atmospheric Hazards

• Low pressure


  • Air that is rising, exerting less pressure than air that is descending
  • Typically associated with cooling and condensation (cloud formation)
• High pressure


  • Air that is descending, exerting more pressure than air that is rising
  • Typically associated with warming and clear skies
• Atmospheric circulation


  Movement of air between latitudes
• Hadley cell


  • Hot air rises at the Equator and cool air sinks at the Tropics
• Ferrell cell


  • Cool air descends at the Tropics and hot air rises at 60 degrees N/S of the Equator
• Polar cell


  • Hot air rises at 60 degrees N/S Equator, sinks at the Poles
• Prediction


  Attempts to forecast when and where a natural hazard will occur based on current knowledge
• Preparedness


  Actions taken before a hazard strikes to reduce its impact, such as educating people or improving building design
• Response


  Actions taken to enable communities to respond to, and recover from, natural disasters, through measures such as emergency evacuation plans, information management, communications or warning systems
• Condensation


  Water changing state from gas to liquid form
• Precipitation


  Rain, snow, hail
• Tropic


  The area between the Tropics of Cancer and Capricorn
• Tropical storm


  Hurricane in Atlantic Ocean, cyclone in Indian Ocean, typhoon in Pacific Ocean
• Frequency


  The number that happen per a set period of time e.g. 10 per year
• Intensity


  The size or magnitude of the hazard e.g. hurricane
• Distribution


  Are things spread out/concentrated? Are there patterns/groups etc.?
• Primary effects


  The immediate impacts as a result of the hazard e.g. flooding
• Secondary effects


  The impacts that result from the primary effects e.g. homelessness
• Monitoring physical changes, such as tracking a tropical storm by satellite, to help forecast when and where a natural hazard might strike