Origins and Nature of Tropical Storms
Tropical Storm: An area of intense low pressure which produces violent weather with high winds and torrential rain.
Tropical storms happen most commonly between the two tropics. The tropic of CANCER and tropic of CAPRICORN.
A tropical storm will occur if the ocean it travels over is more than 27 degrees celcius so they more commonly occur in late summer to early autumn.
How tropical storms occur
1. Several thunderstorms drift over warm seas.
2. The thunderstorms combine with warm air from the sea's surface that has started to rise.
3. More warm air rises and starts to spiral due to the Earth's rotation.
4. More warm air rises and cooler air is sucked downwards into the eye of the storm. Wind speeds begin to increase.
5. The tropical storm moves over the ocean reaching more than 120km/h in wind speeds as it picks up more warm air and more cold air is sucked into the middle.
When a tropical storm gets to land, it loses its source of energy from the warm air from the sea causing it become less powerful as it moves over the land.
Tropical Storms: Impacts and Reduction
ENVIRONMENTAL SOCIAL ECONOMIC
Structural damage to building caused by high winds and torrential rain like roofs being blown off making them uninhabitable so people are left homeless. Animal habitats are lost due to high winds uprooting trees for instance leaving them with no choice but to leave or die. Torrential rain flushes out sewers and causes flooding causing people to catch water-borne diseases making people ill. People lose their jobs so they have no money to buy food or pay bills so they starve or end up homeless. There are high repair and insurace costs in the aftermath of a tropical storm as peoples' property has been destroyed. Crops are destroyed as they are flooded so there is no food for people to eat and there is nothing to sell foodwise in order to be more interdependent.
Reducing Impacts: Short Term Long Term
Send out search and rescue teams. Clear roads and route ways. Provide clean water from stand pipes. Set up tents to house the homeless and feeding stations to feed them. Rebuild roads and infrastructure. Introduce tough building regulations. Produce a TV programme about the disaster.
Prediction and Preparation
- Radiosonde- it is a weather balloon that is a package of meteorological instruments that measure temperature, pressure, humidity. It is small and leightweight but can pop easily and can't be controlled.
- Doppler Radar- it is very specialised to measure rainfall. Colours show amounts of rainfall.
- Satellite tracking- satellite images can use visible and infrared images to show how a storm grows and tracking can show the path of a tropical storm.
- Window shutters- it ensures windows don't smash in high winds and cause injury.
- Stilts- Building on stilts means flood water flows beneath buildings instead of into them reducing insurance costs and damage to property.
- Hurricane shelter- Limits damage to property and keeps the homeless safer.
- Evacuation routes- signs show routes to safe places and the routes finish at emergency evacuation points.
- Emergency kit- contains a torch, medication, water and food. It contains essentials needed if an evacuation has called.
Katrina struck in 2005 and hit three main states in the USA. These are Mississippi, Louisiana and Alabama.
Impacts: ECONOMIC SOCIAL ENVIRONMENTAL POLITICAL
Louisiana: Widespread looting occurs. Levees were overwhelmed so the city of New Orleans flooded.
New Orleans: 80% of New Orleans was submerged under water. One million people were evacuated.
Mississippi: 100 people died. 110 people were reported to have drowned. 100,000 people made homeless in Gulfport.
Alabama: The poultry industry lost 100,000 chicks.
Wider impacts: A total of 1836 people were confirmed dead. Pelicans and turtles' habitats were destroyed. Bush (president) was criticised for responding too late to the disaster.