On uncommon cyclones in the Arabian Sea
Context:
Recently, there has been an excitement about a rare August cyclone — named ‘Asna’ — born from the transition of a strong land-born depression onto the warm Arabian Sea.
- Unlike the common cyclones, the North Indian Ocean, especially the Bay of Bengal and Arabian Sea exhibits a unique a unique behavior.
- It experiences two cyclone seasons.
Relevance:
GS-01 (Physical Geography)
Dimensions of the Article
- What is a Cyclone?
- Why Does the North Indian Ocean Have Two Cyclone Seasons?
- Why is the Indian Ocean Unique?
- The Role of Climate Change
- About Asna, a Rare August Cyclone
- Implications for India
What is a Cyclone?
- A cyclone is a large air mass that rotates around a strong centre of low atmospheric pressure.
- It is characterized by rapid inward air circulation around a low-pressure area that brings violent storms and adverse weather conditions.
- It is generally originated in warm tropical or subtropical waters.
- And, they are classified into tropical cyclones and extratropical cyclones.
- The North Indian Ocean that covers the Arabian Sea and the Bay of Bengal is a key area where cyclones form.
Why Does the North Indian Ocean Have Two Cyclone Seasons?
- Due to the monsoonal wind patterns that dominate the North Indian Ocean region, the area experiences two cyclones, namely: Before the monsoon (April-June) and after (October-December).
- Before the monsoon (April-June):
- As the sun crosses over the Northern Hemisphere, it heats up the Arabian Sea rapidly.
- However, Bay of Bengal is relatively warmer than the Arabian Sea but warms further and begins to produce atmospheric convection and rainfall.
- The trough that brings rainfall in Kerala arrives in Mid-May itself over the Bay of Bengal.
- The post-monsoon season:
- The post-monsoon season is the northeast monsoon season for India that brings significant amounts of rain over several States.
Why is the Indian Ocean Unique?
- Connections through ‘Oceanic Tunnels’: The Indian Ocean has connections to both Pacific and Southern Ocean through oceanic tunnels. Warm water from the Pacific flows into the Indian Ocean, while cooler water from the Southern Ocean enters at deeper levels.
- Seasonal changes in wind: The unique double cyclone is attributed by the influence of Arabian Sea and Bay of Bengal to seasonal changes in wind patterns.
The Role of Climate Change
- Warming of Indian Ocean: Due to the inflow of heat from both the pacific ocean region and the southern regions, it is affecting the cyclogenesis (the formation of cyclones). The north Indian Ocean and the monsoon are now responding to related climate change drivers from tropical oceans as well as from pole-to-pole influences.
- Affecting global weather patterns: The Ocean’s rapid warming is affecting the heat uptake by the Pacific Ocean and the sinking of heavy waters in the north Atlantic Ocean. This is acting like a clearinghouse for ocean warming during climate change which affects cyclogenesis, cyclone numbers, and their responses to climate change over the Indian Ocean.
About Asna, a Rare August Cyclone
- Cyclone Asna was formed in August 2023 in the Arabian Sea. It is known to be an unusual event in the region as cyclones are not known to be forming in this region during August.
- This is the first north Indian ocean cyclone in August since 1981.
- Cyclone Asna, which formed in August 2023, was an unusual event for the Arabian Sea.
- One unique aspect of Asna is that, it developed from a strong land-born depression rather than forming directly over the ocean. This depression, which had already caused heavy rains in western India, intensified over the warm waters of the northern Arabian Sea, eventually becoming a full-fledged cyclone.
Implications for India
- The sudden change in the pattern and the unexpected nature of the climate poses a significant challenge for the country.
- The coastal regions are most vulnerable as the region should bare the impacts on the agriculture, infrastructure, and livelihoods.
- After the recent Heatwave in its extreme form during summers, the sudden change in rain pattern inducing heavy rainfall causing floods and inundation in most of the places, and now, the unpredictable cyclone, is a wake up call to India to be prepared for more such extreme weather events in the future.
Way Forward
- According to the World Meteorological Organization (WMO)- Early warnings, issued within 24 hours of a hazard, can reduce the damage of that event by 30%.
- In-order to cater early warning systems around the world, in line with the UN’s goal of protecting everyone on Earth in five years, the Climate Risk and Early Warnings Systems (CREWS) has been initiated.
- Under CREWS, it has invested over US $100 million in the world’s most vulnerable Small Island Developing States (SIDS), and Least Developed Countries (LDCs).
- Meanwhile, India can utilize Artificial intelligence to improve weather forecasting and early warning systems to reduce the impact alongside investing in infrastructure to withstand extreme weather events.
