what causes hurricanes to increase strength
Hurricanes increase in strength primarily due to the following factors:
1. Warm ocean waters: Hurricanes draw their energy from warm ocean waters. As the warm water evaporates, it provides heat and moisture to the air, fueling the storm. The temperature of the water must be at least 26.5°C (80°F) for a hurricane to form and maintain its strength. The warmer the water, the stronger the hurricane can become.
2. Low vertical wind shear: Vertical wind shear is the change in wind speed or direction with height in the atmosphere. Low vertical wind shear allows the hurricane to develop and maintain a well-organized structure, which is essential for a hurricane to increase in strength. High wind shear can disrupt the storm's circulation, limiting its growth or even tearing it apart.
3. Humidity: A moist atmosphere provides the fuel required for a hurricane to grow and intensify. High humidity levels in the mid and upper troposphere help to create and sustain the thunderstorms associated with hurricanes. Dry air can weaken a storm by preventing the development of thunderstorms and disrupting the storm's circulation.
4. Favorable upper-level atmospheric conditions: An area of high pressure aloft or an upper-level anticyclone can help a hurricane strengthen by providing good outflow conditions at the top of the storm. This allows the air to rise more efficiently within the storm, intensifying the hurricane.
5. Coriolis effect: The Coriolis effect, due to Earth's rotation, helps a hurricane's circulation develop and maintain its structure. Tropical cyclones need the Coriolis effect to form the characteristic counterclockwise (in the Northern Hemisphere) or clockwise (in the Southern Hemisphere) spiral shape. Hurricanes tend to intensify when the Coriolis effect is stronger, which occurs at higher latitudes away from the Equator.
When all these conditions occur simultaneously, they provide the ideal environment for a hurricane to strengthen and become more powerful.