*G12- Tropical Cyclones Flashcards
What is a TC
A low press cell that develops over warm oceans between the tropics
How to now about the number of TCs that occur in a year
Letter in the alphabet
Where to they form
5S and 30S, 5N and 35N
Why don’t they form by the equator
They depend on coriolis force for formation
Different names for acts in different areas *3
*NA- hurricane
*Asia- typhoon
*Australia- Willy willies
They usually occur on what side of continents
East side where seas are warmed by warm currents
TCs move from and to
A region near the equator to the coast of a country
What oceans to they form in SH *2
*southern pacific
*indian
How to spot one on a map *5
*eye in centre
*name
*low pressure cell
*whatever hpa
*latitude
How satellite images show TCs *3
*swirling cloud cover
*cloud free spot in eye
*cumulonimbus
Why would a region get TCs other than location
Sea temps- 28*+
Time occurring
Late summer
What brings flooding
Heavy rains from uplift of warm, moist air (forming cumulonimbus in eyewall)
Why do TCs start degenerating when they reach land
No longer supply of hot, humid air to supply energy
General characteristics *4
*desructive
*strong winds
*heavy rain
*steep pressure gradient and strong winds
Size
600km to 800km
Circulation
Clockwise
How long do they last
3-8 days
ITCZ
Region in tropics where two sets of tropical easterlies converge
Eye
The calm at the centre of a TC
Latent heat
Hidden heat energy that’s given when WV condenses
Adiabatic
Temps change due to change of height and pressure
Factors necessary for their formation *6
*hot moist air
*intense LP cell
*coriolis force
*energy source
*wind speeds
*wind direction
Factors necessary for formation- hot moist air *2
*develop at ITCZ
over seas 28C+ - atmosphere above water unstable
Factors necessary for formation- intense LP cell *3
*hot air rises and forms LP on surface
*tropical jet stream intensifies LP on surface
*air is sucked into cell
Factors necessary for formation- coriolis force *3
non-existent between 5N and S - winds don’t deflect into LP
*CF causes winds to spiral towards LP
*winds - 300km/h
Factors necessary for formation- energy source *3
*high humidity to feed
*draws energy from evaporation of ocean water + the storm releases latent heat which provides energy to drive it
*air more unstable, cb clouds and torrential rain
Factors necessary for formation- wind speeds *2
*Low amounts of light variable winds needed
*Strong winds prevent formation of vortex and disturb low level distribution of WV
Factors necessary for formation- wind direction *2
*east to west
*eastern side of continents
How does a TC continue to get energy *5
*large scale condensation releases latent heat
*energy is provided to sustain cyclone
*cbs form and torrential rain falls
*air pressure so low in eye that some air is sucked down
*calm and cloudless, air warmer due to Adiabatic heating
Gale force
Strong winds within a TC
Forward left hand quadrant aka
Quarter circle
Quarter circle
Area to the left of the storms forward motion
Stages of development- pressure *4
S1- low pressure intensifies, above 1000hpa
S2- below 1000hpa at centre of low and falling
S3- less that 950hpa at centre of low and falling
S4- pressure rising
Stages of development- wind strength *4
S1- starts spiral ing, already at gale force in quarter circle
S2- hurricane strength 30-50km from eye
S3- hurricane strength 300km from eye
S4- winds slowing down
Hurricane strength
150km/h
Stages of development- eye development *4
S1- no clear eye
S2- eye developing
S3- eye fully developed
S4- eye disappearing
Stages of development- clouds *4
S1- building up in quarter circle
S2- in eyewall on both sides of eye
S3- cumulonimbus clouded build up to 10km high in eyewall
S4- clouds breaking up
Stages of development- rain *4
S1- in quatar circle
S2- heavy rain in quarter circle
S3- torrential rain on both sides of eyewall
S4- steady rain, clearing
Eyewall
Walls of cumulonimbus cloud that surrounds the eye
Short term impacts *5
*homes and buildings destroyed
*infrastructure destroyed- emergency services struggle
*power lines and water supplies cut
*spread of disease from infected water
*loss of crops and livestock
Long term impacts *2
*contamination of water supplies when sewage systems are destroyed
*remove valuable topsoil, large scale soil erosion
Stages of development- prediction and warning *2
*International weather agencies should keep a close eye on satellite images
*Warn coastal areas to prepare for moving
Strategies to help prepare- Preparing the community *2
*authorities and public must be aware of specific actions to take
*info and evacuation procedures need to be planned in advance so they know how to prepare
Strategies to help prepare- Land use planning
limit development on coastal areas at risk of surges
Strategies to help prepare- managing the loss *2
*aid- countries offer aid in cash and technical help
*insurance- important management strategy in more developed areas
