Weather and Climate Geography Y8

• Weather recording


  Using certain equipment to analyse the weather
• Key elements of weather


  • Temperature (C)
  • Precipitation (mm)
  • Wind direction (N,S,E,W)
  • Wind speed (km/h or knots)
  • Cloud cover (oktas)
• Measuring and recording weather

  1. Using instruments

  2. Thermometer for temperature

  3. Rain gauge for precipitation

  4. Anemometer for wind direction and speed

  5. Satellite for cloud cover
• Atmosphere


  The layer of air around Earth
• Weather


  The day to day condition of the atmosphere
• Climate

  The average weather of a long period of time e.g. 30 years
• Precipitation


  Water falling from the atmosphere to the Earth's surface
• Wind direction


  Where the wind comes from
• Wind speed


  Measured in knots, 1 knot = 1.85 km/h
• Cloud cover


  Measured in oktas, 0 oktas = no cover, 8 oktas = full cover
• The Sun is the main driver of weather
• How the Sun drives weather


  1. The Sun heats the Earth unevenly

  2. Warm air rises, colder air flows in to replace it as wind

  3. The Sun warms the oceans, causing water evaporation and water vapour in the air
• What happens when air rises

  1. It cools

  2. Water vapour condenses into clouds

  3. Water droplets join to form rain
• Convection rainfall


  Warm air rises, cools and water vapour condenses to form clouds and rain
• Relief rainfall


  Warm, moist air is forced to rise over a mountain, cools and condenses to form clouds and rain on the windward side
• Frontal rainfall


  Warm air mass meets a cold air mass, the warm air is forced to rise over the cold air, cools and condenses to form clouds and rain
• Cumulus clouds


  Small, puffy clouds that form when warm air rises quickly
• Stratus clouds


  Blankets of dull cloud that form when air rises slowly over a wide area
• Air pressure


  The force pressing down on us due to the weight of the atmosphere
• When air is rising

  Air pressure falls
• When air is sinking

  Air pressure rises
• Low pressure weather


  Cloudy, windy, rainy
• High pressure weather


  Clear skies, no rain, possible drought
• Microclimate


  Weather and climate conditions in a small area such as a city or forest
• Smog


  A combination of smoke (pollution) and fog
• Pollution


  Harmful substances entering the environment
• Choropleth map


  A map that shows different colours or shading to show the distribution of information
• Isotherm


  A line on a map joining points with the same temperature
• Urban heat island


  Concentration of high temperatures recorded in a city
• Causes of urban heat islands


  • Dark tarmac surfaces absorb heat
  • Buildings reflect sun's rays
  • Heat generated by industry, people and vehicles
  • Lack of vegetation reduces cooling from transpiration and evaporation
• Effects of urban heat islands


  • Variable and gusty winds
  • Fewer winter frosts and snow
  • Higher night-time temperatures
  • Increased chance of fog and smog
• Actions to reduce urban heat islands


  1. Lighten streets and surfaces

  2. Plant greenery on rooftops and buildings

  3. Plant more trees

  4. Encourage flowing water