How are tropical cyclones named?

Tropical cyclones are rapidly rotating storm systems characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. They form over warm tropical oceans (sea surface temperature > 26.5°C) due to the release of latent heat of condensation. The Coriolis force is essential for creating the cyclonic spin; hence, they do not form at the equator. The storm's progression in the Bay of Bengal, moving west-northwestwards and then northwestwards towards the Andhra-Odisha coast, is typical of post-monsoon cyclones in the Northern Indian Ocean, steered by upper-level atmospheric winds. Understanding the anatomy of a cyclone (the calm 'eye', the destructive 'eye wall', and the spiral bands) is crucial for UPSC Geography. Questions often focus on the conditions required for their formation and the differences between tropical and extratropical (temperate) cyclones.

The naming of tropical cyclones is a structured international process designed to facilitate effective communication and disaster management. It avoids confusion when multiple systems exist simultaneously. The World Meteorological Organisation (WMO) coordinates this globally through regional bodies. For the Northern Indian Ocean (Bay of Bengal and Arabian Sea), the Regional Specialised Meteorological Centre (RSMC) New Delhi, a part of the India Meteorological Department (IMD), is responsible for naming cyclones based on a pre-approved list. This list is generated cyclically by a panel of 13 member countries (including India, Bangladesh, Pakistan, Oman, etc.). The criteria for names—short, easy to pronounce, culturally sensitive, and unique—ensure clear messaging during emergency broadcasts. For UPSC, the institutional framework (WMO, IMD, RSMC) and the collaborative regional approach to disaster nomenclature are important, illustrating regional cooperation in meteorology.

Tropical cyclones are recognized by the WMO as the second-most dangerous natural hazard globally, trailing only earthquakes. The classification system based on maximum sustained wind speed—progressing from a tropical depression (<63 km/h) to a tropical storm (>63 km/h, at which point it is named), and finally to categories like 'severe' or 'very severe cyclonic storm' (exceeding 116 km/h)—is a critical tool for risk assessment and early warning. Cyclone 'Arnab', categorized as a 'very severe cyclonic storm' with winds gusting up to 140 kmph, poses significant threats of coastal inundation (storm surge), heavy rainfall leading to inland flooding, and destructive winds. Effective disaster management requires robust early warning systems (like those provided by the IMD), coastal evacuation plans, and long-term mitigation strategies such as building cyclone shelters and protecting natural barriers like mangroves. UPSC candidates should connect the meteorological data to the Sendai Framework for Disaster Risk Reduction and India's national disaster management policies.