Cyclones Flashcards
Why are names attached to weather events?
It has been found to help people track it’s progress and it allows people to plan and prepare
What is a tropical cyclone?
This is a general term used to describe a rotating system of clouds and storms that form and develop over tropical and sub-tropical waters
When is a tropical cyclone a hurricane or typhoon?
When it reaches wind speeds above 118km/h
What terms under tropical cyclone are used to describe each weather event for its location on the earth?
- Hurricanes are used in the North Atlantic and Pacific coast of the USA
- cyclones are used in the Indian and South Pacific Ocean
- typhoons are used in the western North Pacific
For strong winds, what does it involve?
It can destroy buildings, lift roofs, vehicles and trees and it can destroy power lines
For storm surges, what do they involve?
High tides causing flooding which is due to low pressure as weight of air isn’t holding down the sea as much
What are the hazards that come with cyclones?
- strong winds
- intense rainfall
- storm surges
- landslides
For intense rainfall, what does it involve? Give an example
Where an Average of 1000mm of rain can fall in a single storm e.g. in 1967 typhoon Cana is China brought 2700 mm of rain (higher than annual rainfall in London)
For landslides, what does it involve? Give an example
Where rock and debris move down a slope due to saturated ground which slumps when wet e.g. in 2014, 53 people died in landslides caused by tropical storm jangmi in the Philippines
What are source regions?
The area where the cyclone forms
How big are cyclones on average
650km across
What conditions are needed for a tropical cyclone to form?
- a large still warm ocean where surface temp is over 26.5° for a long period of time
- strong winds in the troposphere that are 10-12km above the earths surface as they rapidly draw warms air up from the earth’s surface
- the Coriolis force = a strong force caused by the earth’s rotation Which is why cyclones only form between latitudes of 5°-30° away from the equator and not on it
What are the steps to a cyclone forming
- Warm air currents rise from ocean causing more air to rush in to replace it which rises as it’s drawn by the draught above
- There is alot of water vapour from up draughts of air which which condenses to produce cumulonimbus clouds
- Coriolis force causes rising currents of air to spiral around the centre of the cyclone. Air then rises and cools then some descends to form the calm eye of the storm
- The cyclone tracks away from the source and is fed new heat and moisture from the ocean causing it to grow
- Once it hits land it looses the ocean and no longer has an energy source so air pressure rises as temp falls, winds drop, rainfall decreases and it dies down to a simple storm
What are primary effects?
Events that happen immediately as a result if a hazard
What are secondary effects?
Events that happen after the hours, days and weeks after the hazard
Where was the location of hurricane Katrina?
Include the state, what it borders and use compass directions
It happened in New Orleans in Louisiana. It borders Texas, Arkansas and Mississippi in south of America
When did hurricane Katrina start and end?
From 24th August 2005 to the 30th August 2005
What category storm was hurricane Katrina
Category 4-5
What was the pressure of hurricane Katrina
902 mb of pressure which is very low making it a powerful storm
What was the wind speed of hurricane Katrina
145mph
How quickly did hurricane Katrina escalate?
By 27th of August it already became a category 3 storm
What were the social impacts of hurricane Katrina?
- 1836 people died of drowning
- 1million people got misplaced
- 100,000 temporary homes were needed