Weather And Climate Flashcards
What is a tropical cyclone?
Tropical cyclones are areas of extreme low pressure. This means air is rising, causing “low pressure’ on the earth’s surface. The maximum sustained surface wind speed (using the U.S. 1-minute average) ranges from 34 knots (39 mph or 63 kph) to 63 knots (73 mph or 118 kph).
Where are the source areas for tropical cyclones found? Why are they found here?
5-15* north and south of the equator, because this is where the ocean is warmest
• What are tropical cyclones known as when they occur:
• in the Atlantic Ocean
• in the Indian Ocean
• in the north west Pacific
• close to Australia
• Hurricanes
• Cyclones
• Typhoons
• Willy willies
Identify three physical hazards that can occur when cyclones make landfall.
Strong winds - destroy properties,infrastructure and crops
Storm surges - cause flooding of property and farm lands
Landslides - caused by heavy rain
Tornadoes - formed during tropical storms can cause devastation to property and infrastructure
Aid - hampered due to communications being destroyed
Give two economic, social and environmental impacts of tropical storms.
Economic:
Loss of business and closure
during evacuations | loss of crops i repairs to infrastructure | damage to buildings
Social:
Deaths and injuries | psychological trauma | homelessness | families split during evacuation
Environmental:
Damage to coastal ecosystems such as mangrove swamos and coral reets i farmland polluted by saltwater from storm surges | coastal erosion
How do countries prepare for tropical storms?
• Monitoring - use of satellites and aeroplanes to monitor weather systems
• Prediction - monitoring changes in the formation and path of the tropical storm
• Protection - constructing buildings that can withstand the impact of tropical storms
- Planning - evacuation plans, education and creatins exclusion zones.
Describe the formation of a tropical storm.
Ocean temperatures are 26.5 or higher.
Warm air above the ocean rises, creating strong convection and the formation of
thick clouds. As more water evaporates from the ocean it rises, condenses forming clouds and releases latent energy. The system then begins to rotate. rastery trade winds push tropical storms.
If they move over warm water the cyclone can intensify increasing its size and wind speed.
Why don’t tropical cyclones occur on the equator or between o and 5’ north and south?
The Coriolis force is too weak here.
Where does the energy from a tropical cyclone come from?
Oceans warmed by the sun.
Identify three characteristics of tropical cyclones.
• Circular in shape, between 100 and 1500 km wide
• Rotate anti-clockwise in the northern hemisphere and clockwise in the southern hemisphere
• A central eye 30-50km wide, with almost no wind and clear skies
• Low air pressure (870-900 millibars)
• Very strong winds around the eye (from 120 to over 200 km.h
