Weather Hazards Flashcards
1
Q
high pressure
A
- sinking air
- calm clear or sunny
- sometimes trapped cloud or fog
- DRY
2
Q
low pressure
A
- rising air
- as air rises and cools clouds and rain form
- BAD WEATHER
- storms are areas of low pressure that bring strong winds and heavy rain
3
Q
what is the coriolis effect
A
tropical storms ROTATE anti-clockwise in the northern hemisphere and clockwise in southern
4
Q
what is the ITCZ?
A
2 warm air masses that meet at the equator
5
Q
what are jet streams
A
strong, high altitude currents of air
6
Q
HADLEY CELL
A
equator, low pressure
7
Q
FERRELL CELL
A
- 30° N/S, high pressure
8
Q
POLAR CELL
A
- 60° N/S, low pressure
9
Q
what factors are necessary for a tropical storm to form?
A
- sea temp ABOVE 27°C to a depth of 60 metres
- earth rotating generates spin = coriolis effect
- light winds, carries storm but doesn’t break up clouds
- thunderstorms clustered
- only occur late summer/early autumn
- LOW air pressure
- between 8-20° latitude (tropical)
- over large body of water
10
Q
how do tropical storms form?
A
- need lots of heat, form over seas
- sun is close to equator, providing energy to heat ocean
- warm ocean heats air above it causing it to rise rapidly
- water evaporates quickly from hot surface of ocean = rising air contains lots of water vapour
- rising air starts to spin (coriolis effect) = eye of storm is calm
- as the air rises it cools, condenses + forms clouds
- rapidly rising air creates areas of low pressure
- low pressure sucks in air, causing strong winds
- once the storm moves over land it loses energy and fades
11
Q
where are the strongest winds!
A
eye wall
12
Q
how will climate change affect tropical storms
A
- temp increased = sea is warmer
- tropical storms will happen more as sea is warmer for longer
- happens in more new places as sea will be warmer
- stronger as sea levels rise so flood small/low lying islands. storms can be powerful for longer
13
Q
what were the PRIMARY IMPACTS of Typhoon Haiyan?
A
- 5metre high storm surge with 314km/h winds
- killed 6190
- power interrupted, 4.1 mill homeless, 1.1 homes damaged
- rice + seed sticks damaged. cost $53 mil. 1.1 mil crops damaged
- 75% of fishermen + farmers lost income
- airport destroyed (no aid or evacuation)
- 90% of tacloban destroyed
14
Q
what were the SECONDARY IMPACTS of Typhoon Haiyan?
A
- oil barge ran aground = 800,000l oil spill
- contaminated 10 hectares of mangroves
- looting - survivors fought for food and supplies
- price of rice increases by 11%
- 8 deaths in rice stampedes
- diseases and infections spread
- homelessness + begging = more deaths
15
Q
what was the RESPONSE of Typhoon Haiyan?
A
- president televised a warning
- 800000 evacuated before storm
- supplies arrived soon after airport reopened
- large companies donated $1.5 bil
- Build Back Better
- no build zone along coast
- storm surge warning system
- mangroves