Cyclones Flashcards
What is a tropical cyclone?
A rotating system of clouds and storms that form and develop over tropical or subtropical waters.
What speed does a cyclone have to reach to be known as a hurricane, typhoon or cyclone?
118km/hr.
Where is ‘hurricane’ used?
North Atlantic and Pacific coast of USA.
Where is ‘cyclone’ used?
Indian and South Pacific Ocean.
Where is ‘typhoon’ used?
Western North Pacific (Japan).
What scale is used in the North Atlantic and North eastern Pacific oceans?
Saffir-Simpson Hurricane Scale (from category 1 to 5).
What scale is used in Japan?
Meteorological Agency’s Scale.
What scale does Australia use?
Tropical Cyclone Intensity Scale.
What hazards do tropical cyclones bring?
Strong winds, storm surges, intense rainfall, landslides.
What is needed for a tropical cyclone to form?
A large, still, warm ocean. Strong winds high in the troposphere 10-12km above the Earth’s surface. Coriolis force between 5 and 30 degrees latitude.
What is air pressure like in tropical cyclones?
A lot lower than normal and the bigger the difference in air pressure, the stronger the winds.
What is the first stage in tropical cyclone formation?
Warm air rises and more air rushes in to replace it which then rises too.
What is the second stage in tropical cyclone formation?
Risen air contains high volumes of water vapour from the oceans which condense to form cumulonimbus clouds.
What is the third stage in tropical cyclone formation?
Coriolis force causes rising currents of air to spiral around the centre (the eye of the storm) so it resembles a whirling cylinder.
What is the fourth stage in tropical cyclone formation?
As the tropical cyclone tracks away from its source, it is fed new heat and moisture from the oceans, enlarging it.
