Weather and Climate gateway 3 part 1 oops

Question 1

where are tropical cyclones found?

Answer 1

• tropical or subtropical waters
• near the equator but not at the equator
• 8-15 degrees N/S

Question 2

characteristics of tropical cyclones

4

Answer 2

1. eye-an area with low pressure, calm water and clear skies
2. centre of tropical cyclones has cool descending air in the upper atmosphere at high altitudes
3. eyewall -heaviest rainfall, greatest windspeed
4. eyewall is made up of bands of thunderstorms

Question 3

how tropical cyclones are formed

Answer 3

1. warm waters of above 26.5 degrees celcius results in an area of low pressure forming over the sea, causing the air parcel to heat up and rise.
2. an area of low pressure forms in the middle and the surrounding area with warm moist air rushes to fill the gap. winds pick up moisture as they travel towards the area of low pressure. the steep pressure gradient results in strong winds spiralling inwards and upwards at high speeds
3. air parcel cools as it rises. There is higher pressure at higher altitudes and this prevents further cloud formation. This forms a region of calm and clear skies known as the eye
4. at high altitudes upon reaching saturation, in the presence of condensation nuclei, condensation occurs. Latent heat is released resulting in a higher temperature, resulting in the area of low pressure being sustained. There is rapid cloud formation along the eyewall where there are bands of thunderstorm clouds with high of windspeeds 119km/h or more due to high pressure gradient and high precipitation
5. In the N hemisphere, the coriolis effect causes the topical cyclone to deflect to the right and move anticlockwise. In the S hemisphere, the coriolis effect causes the tropical cyclone to deflect to the left and move clockwise

Question 4

What are the hazards associated with tropical cyclones?

3

Answer 4

1. storm surges
2. strong winds
3. torrential rain

Question 5

storm surges elab (where, what it is, how it forms, hazard and eg)

Answer 5

-at coastal areas only
-sudden rise in sea level causes water to be piled up against a coastline beyond normal conditions at high tide
-causes by low air pressure and strong winds as intense low pressure in the eye causes sea levels to rise and the wind pushes the water towards the coast creating huge waves
-destroys property and causes high death toll
(eg 2008, Hurricane Ike causes a storm surge 4-6m above normal tide levels. Estimated property damage was US$24.9 billion)

Question 6

strong winds elab (where, the hazard and eg)

DUN DUN DUNNNNN cue creepy piano sounds

Answer 6

• coastal areas only
• damages or destroys infrastructure, injures people when loose debris flies and hits people or buildings (impacts a larger area than storm surges)
• eg 1992, Hurricane Andrew. Strong wind speeds of up to 177km/h caused widespread damage in USA. Damage to infrastructure disrupted power supply and 150,000 homes had no electricity

Question 7

torrential rain elab (where, what it is, hazards and eg)

Answer 7

• both coastal areas and further inland
• large amounts of rainfall causes inland flooding and adds to the flow of water in rivers and streams causing them to overflow
• destabilises slopes when there is too much water in the soil and excess water causes it to be unstable. This leads to landslides which can entirely remove or crush buildings
• places further inland are affected by heavy rainfall for several days
• eg 2003, Hurricane Isabel flooded rivers across many states in USA. Damage was more than US $2.23 billion

Question 8

impacts of tropical cyclones

3

Answer 8

1. physical
2. economic
3. social

Question 9

physical impacts of tropical cyclones

Answer 9

-damage to infrastructure makes it difficult to transport food, clean water, medicine.
-Communication networks are distrupted
(eg 2009, Hurricane Katrina in Phillipines. Damage to roads hindered rescue work and 80% of health centres were destroyed. This made it difficult to distribute food and medicine)

Question 10

economic impacts of tropical cyclones

Answer 10

-cost of repairs of damaged property and infrastructure and loss of income due to damaged crops causes the country to lose a lot of money
-expensive to repair
(eg Hurricane Katrina, New Orleans had damage that cos US$81 billion and a large portion is to repair more than 200,000 homes)
-great economic costs
(eg Cyclone Yasi, Queensland. 75% of banana crop and US$ 350 million was lost)
-There is food shortage. Food aid is provided but flooded roads make it difficult to have access to food or food aid
(eg Cyclone Nagis in Myanmar, 2004. US$4 billion was used to repair infrastructure and provide humanitarian aid)

Question 11

social impacts of tropical cyclones

Answer 11

-disruption to water supply, sanitation and hygiene facilities. Water pipes or pumps may be damaged so there is no fresh water.
-There may be flooding as sewage flows into and contaminates existing water supplies and this leads to the spread of water-borne diseases such as cholera. There is the spread of diseases transmitted by insects like dengue fever. It is difficult to provide adequate care due to large-scale flooding and the fast rate that the disease spreads
(eg 2009, Cyclone Aila, India. People drank contaminated water and this led to a cholera outbreak. 1000 infected, 14 deaths)
-displacement of people. (eg Hurricane Katrina caused hundreds of thousands of people to lose their homes so they stayed in temporary shelters)