Question

What causes cyclone?

Answer 1

Water in oceans heats due to sunlight. This produce warm and moistureous air above it. The air rises due to its higher temperature producing an area of low pressure.
Air form other places rushes to fill the warm airs' place. the risen air drops in temperature and form clouds. these block the incoming cool air and thus deflects it. If this effect continuous for long period of time the low pressure falls heavily. thus a rotating mass of air is produced to sustain the low pressure. the energy for this rotatio is supplied by the warm ocean. There are many other factors that effect the speed of a cyclone.