Tropical storms 4 markers Flashcards
What are tropical storms?
Rotating spirals of clouds
What happens when storms move over land?
Storms decline when they move over land or cold water as they loose their energy source.
Can storms form over the equator?
No
Do all storms have eyes?
No only mature storms develop an eye at the centre
How can tropical storms be predicted?
Geostationary satellites as well as land and based recording centres and aircraft gather data. Information is compared to computer models so the path can be predicted, and warnings issued
How are the magnitude of tropical storms determined?
Measured using the Saffir- Simpson scale, with largest storms reaching category 5
What temperature do water need to be for tropical storms to form?
27.5°C
What hazards are associated with tropical storms?
Rainfall, storm surges and storm winds
What are tropical cyclones?
A generic term for a low pressure system of topical or sub tropical waters with organised convection (i.e thunderstorm activity) and winds at low levels circulating either anti-clockwise or clockwise
Which direction do winds circulate in the northern hemisphere?
Anti-clockwise
Which direction do winds circulate in the southern hemisphere?
Clockwise
What are the summarised 4 stages of hurricane formation?
1- Easterly wave
2- Cluster of thunderstorm
3- storm moves over the atlantic
4- Hurricane
What is a meteorological wave?
A disturbance in the atmosphere over sub Saharan Africa
What does the disturbance form?
A thunderstorm over the rainforest of western Africa, which may cause many thunderstorms to develop
What happens once the thunderstorms reach the Atlantic ocean?
They begin to group, circle each other and then combine, meaning a tropical storm has then formed
What happens after the tropical storm has formed?
The tropical storm gathers strength and when the wind speed reaches at least 74mph, a tropical revolving storm is born- hurricane
What is weather?
The day by day changes in the atmosphere, mainly based on precipitation and temperature.
What is climate?
The long term average of the weather
What are the 4 isothermal layers of the atmosphere?
Troposphere, stratosphere, mesosphere, and thermosphere
How are the four layers of the atmosphere categorised?
by uniform changes in temperature
What does the troposphere make up?
80% of the atmosphere, 16km high
What is the environmental lapse rate?
Changes in temperature caused by decrease in pressure at height
What is the Coriolis effect?
Causes fluids like water and air to curve as they travel across the earths surface
What’s the pressure like at the poles?
High
What’s the pressure like at the equator?
Low
What happens to windspeed if there is the greater difference in pressure?
It will increase
What are anticyclone winds?
Air moves from high pressure to low pressure to fill the void of low pressure. (high pressure diverging air)
What are cyclone winds?
Low pressure converging air (air rising)
How deep do oceans have to be for storms to form?
Water must be warmed to 27° to a depth of 70m
