Global hazards notes

global pattern of air circulation

Atmosphere circulation is the large movement of air by which heat is distributed on the surface of the Earth

hadley cell - largest cell which forms the equator to between 30° to 40° north and south

ferrel cell - middle where air flows poleward between 60° and 70° latitude

polar cell - Smallest and Weakest cell that occurs from the polls to the ferrel cell

formation of tropical storms

• The Sun heat large areas of the ocean in the summer and autumn. This causes warm, moist air to rise over particular spots.

• Once the temperature is 27°, the rising warm moist air lead is low pressure this eventually turns into a thunderstorm. This causes air to be sucked in from the trade winds.

• With trade winds blowing in the opposite direction and the rotation of the earth involved (Coriolis effect) , the thunderstorms eventually start to spin.

• When the storms begin to spin faster than 74 mph, a tropical storm(such as a hurricane) is officially born.

• With the tropical storm growing in power, more cool air is in the centre of the storm, creating calm, clear conditions called the eye of the storm.

• When tropical storms hit land, it loses its energy source warm oceans and it begins to lose strength. Eventually, it will tire itself out.