Summary of Key Points
Typhoon “Baihaidun” made landfall in Yuhuan, Zhejiang on August 9th with winds reaching force 14, affecting multiple areas in Jiangsu, Zhejiang, and Shanghai (Shanghai issued a red rainstorm warning for the first time in 10 years). This article not only describes the intensity and actual impact of the typhoon but also uses everyday examples to explain the power of winds at force 14, teaches readers how to determine the location of a typhoon based on wind direction, reveals the origin of the name “Baihaidun,” and shares some interesting facts about typhoon naming, making it easy for non-experts to understand the logic behind these names.
Detailed Explanation
1. **How powerful is a typhoon at force 14? Understand it with real-life examples**
Winds at force 14 have speeds of 41.5–46.1 meters per second (42 meters per second when Baihaidun made landfall), which is equivalent to traveling at a speed of approximately 151 kilometers per hour. Imagine sticking your body out of a moving car on the highway and facing the wind (quite dangerous!). More importantly, the pressure exerted by the wind on objects increases in proportion to the square of the wind speed: if the wind speed doubles, the pressure quadruples. The dynamic pressure from a typhoon at force 14 can exert a force of about 70 kilograms on an adult—almost as if being weighed down by a large person.
A typhoon is not a single point but a large circular system of moving air. The radius of Baihaidun’s seventh-level wind circle was 450 kilometers, and since Shanghai is located 350 kilometers from Yuhuan, it was already within the affected area, resulting in strong winds and heavy rain even though it wasn’t directly at the center.
2. **Can you find the typhoon’s center without a weather app? Use wind direction**
Ordinary people can determine the location of a typhoon by observing the wind direction using the “Belo-Brook’s Law”: In the Northern Hemisphere, if you stand with your back to the wind, the low-pressure center (the core of the typhoon) will be to your left front. This is because the Earth’s rotation causes the typhoon to spin counterclockwise, causing the air to flow towards the center and deflecting to the left.
Here’s another tip: Observe changes in the wind direction:
- If the wind rotates clockwise (from northeast to east, then southeast to southwest), you are on the right side of the typhoon (the “dangerous half-circle”), where the combined wind speed from the typhoon and its movement is stronger.
- If the wind rotates counterclockwise, you are on the left side (the “safe half-circle”), where the wind is weaker.
- If the wind direction remains constant but the strength increases significantly, it means the typhoon is moving directly towards you.
In this case, since Baihaidun was moving westward, Shanghai and southern Jiangsu were in its “dangerous half-circle,” resulting in more severe impacts.
3. **How did the name “Baihaidun” come about?**
Typhoon names are not chosen randomly. After 2000, a system was established where 14 regions in the Northwest Pacific (including China, Japan, and Hong Kong) each contributed 10 names, creating a total of 140 names to be used in rotation. In 2005, Hong Kong held a naming competition, and the initial candidates “Taiji” and “Mukam” were rejected due to negative connotations in other languages. The final names chosen were “Baihaidun” (a large marine panda, a first-class protected animal in China) and “Shizishan.”
The name “Baihaidun” had been used previously in 2008, 2015, and 2020, but this was the first time it affected land on the Chinese mainland.
4. **Fun facts about typhoon naming**
- Origin of names: Some say they come from the Greek mythological storm monster “Typhon,” which was later adapted into English; others suggest they are transliterations of Cantonese terms for strong winds (“toi fung”).
- Ancient distinctions: In the Qing Dynasty’s “Fujian Tongzhi,” storms that came quickly and disappeared quickly were called “hurricanes,” while those that lasted for several days were called “taisuns.” Initially, the term “typhoon” emphasized the duration of the storm.
- Name rotation and removal: Names are reused, but if a typhoon causes severe damage (like Typhoons “Sangmi” and “Haiyan”), it will be permanently removed from the list, and a new name will be assigned.
Next time a typhoon comes, try standing with your back to the wind and see if the area to your left front is the center of the typhoon. It turns out that meteorological knowledge can be quite practical and interesting!