Cyclone

According to WMO (World Meteorological Organization)- “Cyclone is a low pressure system with sustained winds of atleast 34 knots (63 km/h) and a closed circulation pattern.”

Favourable conditions for the formation of Tropical Cyclones-

1. High Humidity i.e around 60-80%.
2. Vertical Wind Shear should be low (< 10 m/s).
3. Warm Ocean waters with temperature ≥ 26.5 °C .
4. Low pressure area.
5. Convergence of winds with the upper level of divergence.
6. Presence of Coriolis Force.

Differences between Tropical and Temperate Cyclones –

1. Origin – Tropical cyclones form only on seas with temperature more than 26.5 °C in between 10° to 30° N and S of the equator ex-Hurricanes whereas Temperate cyclones can be formed both on land as well as seas in between 35° to 65° N and S of equator ex- European Windstorms .
2. Shape – Tropical cyclones are elliptical in shape where as Temperate cyclones are in shape of of inverted V .
3. Lifespan – Tropical cyclones doesn’t last for more than 1 week whereas Temperate cyclones may last for 2 to 3 weeks .
4. Movement – Tropical cyclones move westward then poleward whereas Temperate cyclones move eastward then northeastward.
5. Intensity – Tropical cyclones are more intense(Category 1 to 5) as compared to the Temperate cyclones.

Understanding these favourable conditions and differences will help us to predict,prepare and track the movements of cyclones by using effective mitigation strategies like – early warning system,storm shelters, evacuation drills,remote sensing etc .

Early warning systems alert communities of impending cyclones through timely and reliable forecasts , enabling evacuations and preparations to minimize damage.India’s early warning systems for cyclones include IMD’s Doppler Radar, Satellite Imagery, and Mobile Alerts. Examples – Cyclone Phailin (2013) and Fani (2019) saw timely evacuations, minimizing casualties. India’s National Disaster Management Authority’s (NDMA) mobile app and SMS alerts also enhance preparedness.

Effectiveness of Early Warning System –

1. Timely alerts from early warning systems enable swift evacuations, preparations and safety measures, minimizing cyclone related casualties and damage through precise forecasts and urgent notifications.
2. Reduce cyclone related casualties by providing critical lead time for evacuations, shelter seeking and safety measures, saving thousands of lives annually.
3. Enhance preparedness by triggering proactive measures through evacuations, emergency resource deployment, infrastructure protection and public education, ensuring communities are ready to respond effectively.
4. Yield economic benefits by minimizing damage to infrastructure, agriculture, and property, reducing loss of livelihoods and lowering post-disaster rehabilitation costs and economic downtime.

Limitations of Early Warning Systems (EWS) in cyclone prone areas include forecasting errors, communication gaps and infrastructure constraints. Technological advancements address these by improved satellite imaging, AI enhanced forecasting, mobile apps, IoT sensors and drone based monitoring enhance accuracy, speed and reach, optimizing cyclone preparedness and response.

Cyclones devastate communities by causing loss of life, infrastructure damage, economic disruption, environmental degradation and displacement with long term effects on ecosystems, biodiversity and psychological well being of affected populations.

Impacts of Cyclones on ecosystems and biodiversity – 

1. Cyclones alter species composition by disrupting food chains, favoring invasive species and reducing native populations, leading to changes in ecosystem structure, function and biodiversity, potentially extirpating vulnerable species locally.
2. Cyclones trigger biodiversity loss through habitat destruction, population decline and local extinctions, eroding genetic diversity, disrupting species interactions and altering ecosystem processes, compromising ecosystem resilience and ecological integrity.
3. Cyclones cause ecosystem degradation through habitat destruction, soil erosion, water pollution and disruption of nutrient cycles, weakening ecosystem resilience, altering ecosystem services and reducing ecological function and biodiversity.
4. Cyclones increase ecosystem vulnerability by weakening natural barriers, altering coastal geomorphology and disrupting ecosystem processes, making communities more susceptible to future storms, flooding and climate change impacts.
5. Cyclones displace species, altering habitats and populations, forcing migrations and disrupting delicate ecosystem balances suddenly.

Cyclone recovery efforts offer opportunities for ecological renewal through habitat restoration, reforestation, species reintroduction, and ecosystem-based adaptation, enhancing resilience, promoting biodiversity, and supporting sustainable ecosystem services and community livelihoods.