Weather Hazards Flashcards
Economic Impact
The effect of an event on the wealth of an area or community.
Environmental Impact
The effect of an event on the landscape and ecology of the surrounding area.
Extreme Weather
This is when a weather event is significantly different from the average or usual weather pattern, and is especially severe or unseasonal. This may take place over one day or a period of time. A severe snow blizzard or heat wave are two examples of extreme weather in the UK.
Global Atmospheric Circulation
The worldwide system of winds, which transports heat from tropical to polar latitudes. In each hemisphere, air also circulates through the entire depth of the troposphere which extends up to 15km.
Immediate Responses
The reaction of people as the disaster happens and in the immediate aftermath.
Long-term Responses
Later reactions that occur in the weeks, months and years after the event.
Management Strategies
Techniques of controlling, responding to, or dealing with an event.
Monitoring
Recording physical changes, such as tracking a tropical storm by satellite, to help forecast when and where a natural hazard might strike.
Planning
Actions taken to enable communities to respond to, and recover from, natural disasters, through measures such as emergency evacuation plans, information management, communications and warning systems.
Prediction
Attempts to forecast when and where a natural hazard will strike, based on current knowledge. This can be done to some extent for tropical storms (and volcanic eruptions, but less reliably for earthquakes).
Primary Effects
The initial impact of a natural event on people and property, caused directly by it, for instance buildings being partially or wholly destroyed by a tropical storm.
Protection
Actions taken before a hazard strikes to reduce its impact, such as educating people or improving building design.
Secondary Effects
The after effects that occur as indirect impacts of a natural event, sometimes on a longer timescale, for instance impact on access to potable water can lead to the spread of disease.
Social Impact
The effect of an event on the lives of people or community.
Tropical Storm
Hurricane, Cyclone, Typhoon
An area of low pressure with winds moving in a spiral around the calm central point called the eye of the storm. Winds are powerful and rainfall is heavy.
What causes winds?
Wind is large scale movements in air caused by differnce in air pressure. Winds move from high pressure to low pressure. Warm air rises causes low pressure.
What is the weather like at the equator?
Sun warms the earth, heat rises, rising air leads to low pressure, clouds and rain.
What happens to hot air rising at the equator?
As it rises, the air cools and moves out to 30 degrees North and South of the Equator.
What happens to hot air that cools 30 degrees North and South of the Equator?
Cool air sinks, creates high pressure, no clouds and low rainfall. The high pressure then creates surface wind flowing to the Equator or towards the Poles. These winds are called Trade Winds.
How do tropical storms form over warm water?
Develop when sea temperature is greater than 27 degrees and difference in wind speed is low between lower and higher parts of the atmosphere.
Warm air rises and condensation occurs. This releases a huge amount of energy.
Where do tropical storms occur?
Between 5 and 30 degrees North and South of the Equator. The sea is warm enough. Most occur in Northern hemisphere in late Summer and Autumn.
What are the features of a tropical storm?
Circular in shape, hundreds of kilometres wide, last 7-14 days. Anticlockwise in the North. Clockwise in the South.
Features of the eye of a storm?
Centre is the eye and is caused by descending air. Low pressure, light winds, no cloud, no rain, high temperature.
Structure of a storm?
Eye surrounded by an eye wall, spiralling rising air, strong winds, storm clouds, torrential rain, low temperatures.
The edge of storm, the wind drops, clouds become smaller and rain less intense.
