Typhoon Koppu recently garnered global attention after causing at least four deaths in the northern Philippines and affecting more than 200,000 people across the country. This event underscores the importance of understanding this devastating weather phenomenon and the process by which typhoons form. In this article, we will explore all aspects related to typhoons in detail.
What is a typhoon?
A typhoon is essentially a tropical cyclone that develops in the western Pacific Ocean. Like a hurricane, its formation is associated with areas of low pressure; however, the term 'typhoon' is specifically used to refer to these systems in the western Pacific region. If such a phenomenon occurs in the eastern Pacific, it is called a hurricane. This indicates that both typhoons and hurricanes are the same meteorological phenomenon, but named differently depending on their geographic location.
How does a typhoon form?
The formation of a typhoon is a complex process involving several atmospheric factors . Generally, it occurs when an atmospheric wave in the Pacific Ocean begins to rotate in the same direction as the Earth's rotation. This results in high pressure at the outer edge of the wave and low pressure at its core. Such a phenomenon can be classified as a typhoon if its rotational speed reaches 120 km/h.
The following describes the factors necessary for the formation of a typhoon:
- Water temperature: It is crucial that the ocean surface temperature is higher than the 26°CThis favors a high evaporation that generates water vapor, which contributes to the formation of clouds by convection.
- Low wind shear: Wind shear refers to the change in wind speed and direction at different altitudes. It is essential that this shear be low to prevent decoupling between the upper and lower parts of the convective system.
- High levels of relative humidity: High relative humidity is required from the surface to high levels of the troposphere for a typhoon to form and persist, as detailed in the article on how a cyclone forms.
- Presence of a wave at height: These atmospheric waves moving across the tropics can be amplified and, along with the other factors mentioned above, lead to the formation of a tropical cyclone.
Furthermore, the Coriolis force is an essential element in the formation of typhoons; it is zero at the equator and increases towards the poles. Therefore, typhoons cannot form at latitudes near the equator, although they are common within the tropical region.
Typhoon season
The peak season for typhoon formation runs from late June to early September . During these months, rising ocean temperatures contribute to the development of various spirals that can become typhoons. It's important to note that, as a result of global warming , an increase in the frequency of these natural phenomena has been observed.
Impact of typhoons and climate change
While typhoons are naturally occurring phenomena, evidence suggests that climate change is intensifying their frequency and impact. As ocean temperatures rise, the energy available to fuel these cyclones increases, which can lead to stronger and more destructive typhoons. The combination of intense winds, heavy rainfall, and storm surges causes devastating flooding and infrastructure destruction, especially in coastal areas where many communities are vulnerable, as discussed in the article on hurricane names.
Typhoon Classification
Typhoons are classified into different categories depending on their wind speed, following the RSMC Tokyo intensity scale:
- Tropical depression: Sustained winds less than 61 km/h.
- Tropical storm: Sustained winds between 62 and 88 km/h.
- Severe tropical storm: Sustained winds between 89 and 117 km/h.
- Typhoon: Sustained winds between 118 and 156 km/h.
- Very strong typhoon: Sustained winds between 157 and 193 km/h.
- Violent typhoon: Sustained winds exceeding 193 km/h.
Differences between typhoons and hurricanes
The main distinction between the terms 'typhoon' and 'hurricane' lies in the geographical location of the phenomenon. Both terms refer to a tropical cyclone, but their usage depends on the region of the world where they occur. While they are called typhoons in the western Pacific, they are called hurricanes when they form in the Atlantic, the Caribbean, or the eastern Pacific. To better understand these differences, it is recommended to consult the article on hurricanes and typhoons.
Typhoons are complex meteorological phenomena that require specific conditions for their formation and have become increasingly destructive as the climate changes. As we continue to confront global warming, it is crucial to understand their nature and the impact they can have on our lives. Safety and preparedness are essential to mitigate the devastating effects these tropical cyclones can cause.
