台风产生的原因 英文的

【专家解说】：The formation of tropical cyclones is the topic of extensive ongoing research and is still not fully understood.[35] While six factors appear to be generally necessary, tropical cyclones may occasionally form without meeting all of the following conditions. In most situations, water temperatures of at least 26.5 °C (79.7 °F) are needed down to a depth of at least 50 m (160 ft);[36] waters of this temperature cause the overlying atmosphere to be unstable enough to sustain convection and thunderstorms.[37] Another factor is rapid cooling with height, which allows the release of the heat of condensation that powers a tropical cyclone.[36] High humidity is needed, especially in the lower-to-mid troposphere; when there is a great deal of moisture in the atmosphere, conditions are more favorable for disturbances to develop.[36] Low amounts of wind shear are needed, as high shear is disruptive to the storm's circulation.[36] Tropical cyclones generally need to form more than 555 km (345 mi) or 5 degrees of latitude away from the equator, allowing the Coriolis effect to deflect winds blowing towards the low pressure center and creating a circulation.[36] Lastly, a formative tropical cyclone needs a pre-existing system of disturbed weather, although without a circulation no cyclonic development will take place.[36]