Hazards- Tropical Storms

Question 1

What is a tropical storm?

Answer 1

• 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

Question 2

How are tropical storms formed?

Answer 2

• 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

Question 3

The Coriolis Effect

Answer 3

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

Question 4

Storm surge

Answer 4

• 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

Question 5

Strong winds

Answer 5

• 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

Question 6

Convective downbursts

Answer 6

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

Question 7

Landslides

Answer 7

• 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

Question 8

River flooding/heavy rainfall

Answer 8

-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

Question 9

Monitoring, measuring and predicting- MAPPING PAST EVENTS

Answer 9

• 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

Question 10

Monitoring, measuring and predicting- AIRCRAFT AND DRONES

Answer 10

• 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

Question 11

Monitoring, measuring and predicting- USE OF SATELLITES

Answer 11

• 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

Question 12

Saffir-Simpson Scale

Answer 12

• 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