Tropical Storms Flashcards
when do tropical storms develop
- when the sea temperature is 27C or higher
- and the wind shear between higher and lower parts of the atmosphere is low
what is wind shear
the differences in wind speed
what happens when the sea is heated to temperatures of 27C and above
- the warm moist are rises and condensation occurs
- this releases huge amounts of energy which makes the storm powerful
what does the rising air from the high sea temperatures cause
- low pressure
- which increases surface winds
why do tropical storms move towards the west
because of the easterly winds near the equator
why do tropical storms spin
because the earths rotation deflects the paths of the winds
why do storms get stronger above water but weaker above land
- above water they get stronger due to the energy from the warm water
- which causes wind speeds to increase
- but above land they lose strength
- because the energy supply from the warm water of the sea is cut off
why do most tropical storms only occur 5 to 30 degrees north and south of the equator
- because this is where the temperatures of the seas are highest
- any further from the equator and the water wouldnt be warm enough to provide the energy for the storm
when are sea temperatures highest in the northern hemisphere, especially over the pacific
in late summer and autumn
what are the main properties of a tropical storm
- they are circular in shape
- hundreds of kilometres wide
- usually last 7 to 14 days
how does the direction that a tropical storm spins change depending on the hemisphere that it is in
- they spin anticlockwise in the northern hemisphere
- and clockwise in the southern hemisphere
what is the center of a storm called
the eye
what is the eye of the storm caused by and how large is it
- it is caused by descending air
- it can be up to 50km across
what is it like in the eye of the storm in terms of the conditions
- there is very low pressure
- light winds
- no clouds
- no rain
- and a high temperature
- it is very calm compared to the rest of the storm
what happens towards the edges of the storm as its intensity decreses
- the wind speeds fall
- causing clouds to become more scattered
- the rain becoming less intense
- and the temperature increasing
what is the eye of the storm surrounded by and what is it like
- the eye wall
- where there is spiralling rising air
- very strong winds of about 160km per hour
- storm clouds
- torrential rain
- and low temperatures
how does the air and its temperature determine the shape of the storm
- the warm rising air is what causes the main body of the storm to be aggressive and intense
- the air cools as it rises and begins to sink down into the center of the main body of the storm
- this descending air clears a space at the center of the storm
- creating the relatively small eye at the center with the large circular body of expanding warm air around it
what is the effect of global temperatures being expected to rise as a result of climate change regarding tropical storms
- it means that more of the worlds oceans would be above 27C
- so more places in the world would experience tropical storms
what two factors of tropical storms would increase as global temperatures begin to rise and why
- their frequency and their strength
- because oceans will stay at 27C or higher for more of the year so the number of tropical storms will increase
- while the higher temperatures also means storms will be stronger which will cause more damage