Typhoon vs Hurricane vs Cyclone

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Typhoon vs Hurricane vs Cyclone
The difference between a typhoon and a hurricane and a cyclone is its location. All start out as tropical cyclones.

The difference between a typhoon, a hurricane, and a cyclone is the region where they occur. Otherwise, they are all the same type of storm — tropical cyclones. Typhoons are tropical cyclones in the Northwest Pacific, hurricanes are in the North Atlantic and Northeast Pacific, while a cyclone refers to tropical cyclones in the South Pacific and Indian Ocean.

Typhoon vs Hurricane vs Cyclone – Where and When

  • Typhoons: A typhoon is a tropical cyclone in the Northwest Pacific, west of the International Dateline. They generally form from May to October.
  • Hurricanes: Hurricanes form in the North Atlantic and Northeast Pacific, predominantly between June and November.
  • Cyclones: Cyclones form in the South Pacific and Indian Ocean. Their season varies, but for the north Indian Ocean, it’s typically April to December, while in the southern hemisphere, it’s usually between November and April.

Can a Hurricane Become a Typhoon?

As a hurricane moves west across the Pacific Ocean, it can cross the International Date Line and change status from a hurricane to a typhoon.

Can a Cyclone Cross the Equator?

A tropical cyclone in the Indian Ocean is a cyclone, regardless of which side of the equator it’s on. The conditions in the southern Atlantic are not favorable for cyclone formation. Cyclones in the Pacific have never crossed the equator and become hurricanes or typhoons. This does not meet it’s impossible, but it’s unlikely since most cyclones move away from the equator rather than toward it.

How Tropical Cyclones Form

Tropical cyclones form over warm ocean waters near the equator. Here’s a step-by-step guide to how these storms form and why they rotate:

  1. Warm Ocean Waters: A tropical cyclone needs a sea surface temperature that is approximately 26.5°C or warmer. This warm water heats the air above, so it rises and forms a low-pressure area.
  2. Evaporation and Condensation: As the warm air rises, it cools, and the moisture it carries condenses into clouds and rain. This process releases latent heat into the atmosphere, warming the surrounding air, causing it to rise as well.
  3. Earth’s Rotation: As the warm air continues to rise, the Earth’s rotation causes the rising air to spin. In the Northern Hemisphere, the rotation is counterclockwise, while in the Southern Hemisphere, it’s clockwise. This phenomenon is due to the Coriolis effect.
  4. Development of the Eye: As the cyclone grows stronger, an ‘eye’ forms at its center. This is a calm and cloud-free zone where the air is descending.

Storm Classification and Naming

But, not all tropical cyclones become typhoons, hurricanes, or cyclones. A storm’s classification depends on its sustained wind speeds:

  • Tropical Depression: Winds up to 38 mph (61 km/h).
  • Tropical Storm: Winds between 39 mph (63 km/h) and 73 mph (118 km/h). It’s at this stage that storms receive a name.
  • Hurricane/Typhoon/Cyclone: Winds 74 mph (119 km/h) and above (for the Saffir-Simpson wind scale).

The naming system is based on pre-decided lists for each region. Once a storm becomes a typhoon or hurricane, it can weaken to a tropical storm or depression and either strengthen again or else dissipate. If a storm is particularly deadly or costly, its name can be retired to avoid confusion with future storms.

Factors That Influence Tropical Cyclone Size and Intensity

Whether a tropical cyclone makes it to named storm status depends on several factors:

  1. Sea Surface Temperature: Warmer waters provide more energy, potentially increasing a storm’s intensity.
  2. Ocean Heat Content: Apart from surface temperature, the depth of warm waters fuels a storm.
  3. Atmospheric Moisture: Humid air intensifies cyclones, as it leads to more rain and latent heat release.
  4. Wind Shear: High vertical wind shear disrupts the formation and intensification of cyclones. Low wind shear is conducive to cyclone development.
  5. Land Interaction: Contact with land usually weakens a cyclone because it cuts off the warm water source.

Typhoon vs Hurricane: Interesting Facts

  • The term ‘hurricane’ comes from ‘Huracán,’ a god of wind and fire worshiped by the Mayans.
  • The word ‘typhoon’ comes from the Mandarin word ‘tau-feng,’ which means long-lasting wind.
  • Tropical cyclones in the northern hemisphere spin counterclockwise, while storms in the southern hemisphere spin clockwise.
  • The deadliest cyclone on record is the 1970 Bhola cyclone in Bangladesh, claiming over 300,000 lives.
  • Cyclones sometimes generate tornadoes within their rainbands.
  • Tropical cyclones help maintain Earth’s heat balance by redistributing heat from the equator to the poles.
  • Some storms change basins and, consequently, names. For example, Hurricane Genevieve in 2014 started as a hurricane in the Eastern Pacific and became Typhoon Genevieve in the Western Pacific.

References

  • Shi, Donglei; Ge, Xuyang; Peng, Melinda (2019). “Latitudinal dependence of the dry air effect on tropical cyclone development”. Dynamics of Atmospheres and Oceans. 87: 101102. doi:10.1016/j.dynatmoce.2019.101102
  • Tory, K. J.; Dare, R. A. (2015). “Sea Surface Temperature Thresholds for Tropical Cyclone Formation”. Journal of Climate. American Meteorological Society. 28 (20): 8171. doi:10.1175/JCLI-D-14-00637.1
  • Xu, Jing; Wang, Yuqing (2018). “Dependence of Tropical Cyclone Intensification Rate on Sea SurfaceTemperature, Storm Intensity, and Size in the Western North Pacific”. Weather and Forecasting. American Meteorological Society. 33 (2): 523–527. doi:10.1175/WAF-D-17-0095.1