Hazards- Tropical Storms Flashcards Preview

A Level Physical Geography > Hazards- Tropical Storms > Flashcards

Flashcards in Hazards- Tropical Storms Deck (12)
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1
Q

What is a tropical storm?

A
  • a violent rotating storm which occurs at mid-latitudes (the tropics)
  • they can only form in warm waters (above 27 degrees) which is why they occur close to the equator
2
Q

How are tropical storms formed?

A
  • strong upward movement of air draws water vapour up from the warm ocean surface
  • the evaporated air cools as it rises and condenses to form towering thunderstorm clouds
  • condensing air releases energy which powers the storm and draws up more water
  • several small thunderstorms combine to form a giant spinning storm (tropical storm which surface winds exceed 120km/h)
  • storm develops an eye where air rapidly descends-most intense winds found in the eyewall
  • storm carried across warm ocean gathering strength and energy
  • upon landfall the storms energy is cut off/friction with land weakens it
  • if storm reaches water again it may regain some strength
3
Q

The Coriolis Effect

A

Caused by the Coriolis force which deflects objects within a rotating system

4
Q

Storm surge

A
  • rises in sea level that occur during tropical storms
  • storm pushes water out when in open water- causing water to spin under the surface
  • when water hits shallower water it is forced upwards
  • low pressure and high winds create storm surges
  • high tides make them more dangerous
5
Q

Strong winds

A
  • caused by differences in atmospheric pressure (wind moves from high to low)
  • wind wants to reach eye of hurricane so it swirls round
  • coastal areas most affected
  • most deaths occur inland as people aren’t as prepared
  • caused by:
    • intense turbulence
    • organised convection
    • wind shear
    • steep terrain
6
Q

Convective downbursts

A

Cool air wants to move downwards- can cause airplanes to drop out of the sky

7
Q

Landslides

A
  • a collapse of a mass of earth or rock from a mountain cliff
  • steep slopes saturated by heavy rainfall makes the rocks unstable and cause a landslide
  • precipitation and surface run off increase change of landslide
8
Q

River flooding/heavy rainfall

A
-torrential rain causes flash flooding 
Factor that make it worse:
-long periods of rainfall 
-steep slopes 
-saturated soils 
-low lying flat land 
-lands surrounding rivers/low lying land/urban areas are more at risk
9
Q

Monitoring, measuring and predicting- MAPPING PAST EVENTS

A
  • by recording which areas are frequently affected by tropical storms it is easier to predict future events
  • allows you to determine which areas need to be evacuated and the necessary preparation
10
Q

Monitoring, measuring and predicting- AIRCRAFT AND DRONES

A
  • drones can record wind speed, temperature, barometric pressure, rainfall and snow
  • release sensors which fall through the storm and send back data to improve forecasting models
  • Global Hawk Drone is equipped with microwave and radar instruments
  • drones can go into parts of the storm that pains can’t
  • unmanned so no one is at risk
11
Q

Monitoring, measuring and predicting- USE OF SATELLITES

A
  • satellites can track features such as temperature, cloud heights, rain, snow and wind speed
  • geostationary operational environmental satellites (GOES) and polar orbiting operational environmental satellites (POES) are used to make long term forecasting
  • CT scan of inside the storm by TRMM satellites
  • there is zero risk with using satellites
12
Q

Saffir-Simpson Scale

A
  • category 1 are the most common as most storms weaken before they reach land (and so cause less damage)
  • using this scale means info can be passed quickly and made available to the public sooner
  • evacuations can therefore take place quicker
  • scale also allows for simple comparisons