James Hickey answered on 17 Nov 2013:
Hey jade021199! Really good and topical question – the devastation in the Philippines was horrible!
I’ll start by saying that a typhoon is the same thing as a hurricane or tropical cyclone. They just have different names depending on where they form. If they form in the North Atlantic Ocean we call them hurricanes. If they form in the north-west of the Pacific Ocean we call them typhoons.
A typhoon (or hurricane) then forms like this:
1. You need warm ocean water that is 27 degrees C or more, and a calm atmosphere (too much wind to start with will prevent a typhoon from forming).
2. The air above the warm ocean is heated up.
3. The hot air rises and takes some moisture with it from the ocean. As it rises it starts to cool down and eventually condenses to form clouds.
4. Because air has risen up from the ocean surface, more air flows in to the ‘gap’ that is left behind. This air then heats up and rises too, meaning more and more air has to fill the ‘gaps’.
5. All the rising air creates huge clouds (called cumulonimbus clouds).
6. The air rushing to fill the ‘gap’ (or low pressure region) creates high winds. But because the Earth is spinning the winds circle towards the centre of the typhoon giving them their famous spinning shape.
7. The typhoon ‘feeds’ itself because the rising air brings heat and energy. This is what ‘drives’ the typhoon.
8. This is the point the typhoon moves towards land (like the Philippines) and can cause lots of destruction.
9. Once over land, there is no rising air and moisture to ‘feed’ the typhoon so they eventually lose power and die out.
I hope that answers your question. There is more information here: http://www.bbc.co.uk/schools/gcsebitesize/geography/weather_climate/weather_human_activity_rev2.shtml and here: http://www.coolgeography.co.uk/GCSE/Year11/Managing%20Hazards/Tropical%20storms/tropical_storms.htm#How_Tropical_storms_form;_. Or if you want to know more feel free to ASK us some more questions.
Julie Speakman answered on 18 Nov 2013:
Thanks to James for his great description of how typhoons get going.
I think the other thing to mention is whether global warming has played a part in this and other similar disasters.
People including the head of the United Nations have warned that typhoons like this have been caused by global warming but this is one of the those subjects where there is lots of debate about how much impact global warming has had. To be honest, it will be very difficult to prove either way.
What is clearer, though, is that the fact that sea levels are rising (which are often also said to be due to global warming) mean populations of people in coastal areas like the Philipines are more at risk when these typhoons do happen.
Saima Rehman answered on 18 Nov 2013:
This question is pretty much covered by James and Julie. I am afraid, I don’t have any extra information to add. I recommend you to look at the figure (link in James answer), and you will learn it so easily.