Earth's Atmosphere

  1. Troposphere - This layer reaches from sea level to about 10 000 metres above earth and contains much of the weather.
  2. Stratosphere - This stretches from 10 000 metres to 50 000 metres above earth and contains the ozone layer that absorbs much of the solar radiation to warm the planet.
  3. Mesosphere - This layer reaches from 50 000 metres to 80 000 metres and is much cooler than the lower layers.
  4. Thermosphere - This layer stretches from 80 000 metres to about 350 000 metres and contains rarefied air that is very hot (about 1000 °C).

Atmospheric Pressure

Seasonal Temperatures

Water in the Air

  1. Evaporation - the movement of ocean, river and lake water into the atmosphere
  2. Condensation - the process whereby clouds form from the evaporated water vapour
  3. Precipitation - falling rain, snow, sleet, hail, fog, mist, dew or frost


Beaufort Scale of Wind Strengths

Beaufort Number General Description Effects at Sea Effects on Land Speed in Knots
0 Calm Sea like a mirror Calm; Smoke rises vertically Less than 1
1 Light air Slight ripples Smoke drifts; Wind wanes not affected 1 to 3
2 Light breeze Small wavelets Wind felt on face; Leaves rustle; Wind vane moves 4 to 6
3 Gentle breeze Large wavelets; Scattered 'white horses' Leaves and twigs in constant motion; Flags extended 7 to 10
4 Moderate breeze Small waves become longer; Frequent 'white horses' Raises dust and loose paper; Small branches move 11 to 16
5 Fresh breeze Moderate waves; Many 'white horses' Small trees sway; Inland waters have crested wavelets 17 to 21
6 Strong breeze Large waves form; Many white foam crests Large branches in motion: Umbrellas used with difficulty 22 to 27
7 Near gale White foam from large waves blows with the wind Whole trees in motion; Inconvenience when walking against wind 28 to 33
8 Gale Moderately high waves of greater length; Edges of crests break into spindrift Twigs break trees 34 to 40
9 Strong gale High waves; Dense foam blown by wind; Crests roll over Slight structural damage (e.g. roof tiles removed) 41 to 47
10 Storm Very high waves with overhanging crests Trees uprooted; Considerable structural damage 48 to 55
11 Violent storm Exceptionally high waves; Sea completely covered with foam Very rare; Widespread damage 56 to 63
12 Cyclone (also known as a hurricane or typhoon) Air filled with foam and spray; Sea completely white Extremely rare; Widespread damage Above 63

Land & Sea Breezes


Low clouds

  1. Stratus - a thin, stretched-out layer of cloud with no rain
  2. Cumulus - lumpy white cloud with no rain
  3. Large Cumulus - large lumpy whitish cloud with some showers

Middle level clouds

  1. Altostratus - a sheet of bluish-grey cloud with light rain
  2. Altocumulus - Similar to cirrocumulus but lower in the sky and grey with no rain
  3. Nimbostratus - a very thick layer of dark grey cloud with heavy to flood rain

High clouds

  1. Cirrus - extremely high and pure white because they are made of tiny ice crystals
  2. Cirrostratus - thin, stretched-out layer of very white cloud with no rain
  3. Cirrocumulus - thin lumpy clouds in rows with no rain






Weather-Measuring Devices

Synoptic Charts or Weather Maps

Australian Weather Map