Typhoon Yagi

Source- This post on Typhoon Yagi is based on the article “Behind Typhoon Yagi becoming the most powerful storm in Asia this year” published in Indian Express on 16th September 2024.

Why in News?

Typhoon Yagi, has emerged as the strongest tropical cyclone in Asia this year and the second most powerful globally after Hurricane Beryl. The typhoon has affected multiple countries, including the Philippines, China, Laos, Myanmar, and Thailand. Vietnam in particular has been hit hardest, with a death toll of around 233.

Typhoon Yagi’s Development and Impact

Typhoon Yagi initially developed as a tropical storm in the western Philippine Sea on September 1. It Intensified to Category 5 cyclone with peak winds of 260 kmph. It is one of only four Category 5 storms ever recorded in the South China Sea.

On September 6, Yagi made landfall in China’s Hainan province with 223 km/h winds and then hit northern Vietnam, and became one of the strongest storms in over a decade for the region. Though it later weakened into a tropical depression, it continued to cause heavy rainfall and flooding, particularly in Myanmar.

Formation of Tropical Cyclones

Tropical cyclones develop over warm ocean waters near the equator. Warm, moist air rises from the ocean surface, creating a low-pressure area. Surrounding higher-pressure air rushes into this low-pressure zone, warming and rising in turn. As the warm air cools, it forms clouds and thunderstorms. The cyclone system strengthens by drawing heat and moisture from the ocean’s surface.

Classification of Tropical Cyclones

The Saffir-Simpson Hurricane Wind Scale categorizes cyclones from Category 1 (119-153 km/h) to Category 5 (252 km/h or higher).

Storms reaching Category 3 or higher are considered major tropical cyclones due to their potential for widespread destruction.

What is the relation between Climate Change and Tropical Cyclones?

There is no complete agreement on how climate change impacts tropical cyclones, as multiple factors influence storm formation and development. However, scientists do agree that rising global temperatures are making tropical cyclones more intense.

A recent study from July 2023 found that cyclones in Southeast Asia are forming closer to coastlines, intensifying rapidly, and staying longer over land. This is linked to higher sea surface temperatures, which have increased by 0.9°C since 1850 and 0.6°C in the last 40 years.

Effect of Warmer Oceans on Cyclones- Warmer ocean temperatures increase evaporation and heat transfer to the air, fuelling storms as they cross hot waters. As a result, tropical cyclones like Typhoon Yagi gather more water vapour and heat, leading to stronger winds, heavier rainfall, and increased flooding when they reach land.

UPSC Syllabus- Environment and Disaster Management