cyclones

A cyclone describes a weather system characterized by swirling winds around a low-pressure centre; wind direction around the low is counterclockwise in the Northern Hemisphere, clockwise in the Southern Hemisphere. Coming in a wide variety of sizes and settings, cyclones cause some of the most dramatic and outright violent weather on the planet, including the tropical cyclones known as hurricanes and typhoons. The science behind cyclones will help you understand why, where and how this weather phenomenon exists.

The National Weather Service defines a tropical cyclone as "a rotating system of clouds and thunderstorms that originated over tropical or sub-tropical areas." The major tropical-cyclone basins include the North Atlantic (including the Caribbean), Eastern Pacific, Western Pacific, North Indian Ocean, Southwest Indian Ocean, Southern Pacific and Australian region. Typically tropical cyclones develop within 5 and 30 degrees of latitude, as they require ocean waters of 80 degrees Fahrenheit or so to form. Winds funnels into a low-pressure disturbance, evaporating warm surface waters and releasing energy as rising air condenses into clouds.

The terminology associated with tropical cyclones can be confusing because people call these dangerous storms by different names in different parts of the world. In the North Atlantic and the Caribbean as well as the northeastern Pacific, they go by “hurricane.” In the Northwest Pacific – the most active tropical-cyclone basin in the world – they’re “typhoons,” while in the Indian Ocean and South Pacific they’re simply “tropical cyclones” or “cyclones.” Tornadoes – much smaller and more localized than tropical cyclones, and capable of generating even higher wind speeds – are occasionally colloquially called “cyclones,” though they’re completely different storms.

Especially strong thunderstorms called supercell thunderstorms – which generate by far most of the world’s strongest tornadoes – exhibit spinning updrafts called mesocyclones. Rotating “wall clouds” may descend from mesocyclones and ultimately form a funnel cloud, which, if it contacts the ground, becomes a tornado. The United States experiences approximately 1,700 mesocyclones a year, with roughly 50 per cent of these turning into tornadoes.

Hurricanes and typhoons may be better known to laypeople, but the cyclonic storms that develop along frontal boundaries in the middle latitudes – called “extratropical cyclones” or “midlatitude cyclones” – are just as significant.

These cyclones – which, unlike their tropical counterparts, develop where sharp temperature gradients exist between adjoining air masses – can be much larger than hurricanes, although their winds are generally weaker. A prominent example of the midlatitude cyclone is the “nor’easter” that often impacts the U.S. East Coast, particularly in winter.

Hurricane-like cyclones called “polar lows” occasionally form over Arctic and Antarctic seas, sparked by frigid air moving over somewhat warmer ocean waters. In the Northern Hemisphere, meteorologists sometimes call polar lows “Arctic hurricanes” because both their energy source – heat transfer from water to air and latent heat released by cloud condensation – as well as their spiralled cloud bands are somewhat similar to a tropical cyclone’s. Polar lows often form quickly, sometimes in less than 24 hours, and can be difficult to forecast.

WMO has applauded the India Meteorological Department’s forecast and updates on super cyclone Amphan as “best practice” as the weather office made a series of predictions that correctly anticipated the path of the cyclone and the associated wind speed.

Issues in cyclone mitigation

Post than pre-focus: Disaster management in India is largely confined to post-disaster relief works. It is more about management than loss prevention.

Population: One-third of the population in India lives in the coastal area. Most of them are marginalized people who are ill-prepared and unable to cope up with a disaster.

Poor response: The warning of a cyclone is not properly communicated between the concerned agencies. In many cases, the warning is not taken seriously by the agencies which cause delayed effort for the prevention of a disaster. This was evident in the recent Ockhi cyclone disaster.

Lack of awareness: among people about the impact and magnitude of the disaster. Also what to act during and post disasters.

Coordination Issues: There is also a lack of coordination between the local communities for search and rescue missions. Also poor coordination state and centre coordination and its agencies.

What are the Measures that need to be taken for mitigation?

Pre Disaster

Provide cyclone forecasting, tracking and warning systems. Construction of cyclone shelters, cyclone-resistant buildings, road links, bridges, canals, drains etc. Establishing Early Warning Dissemination System (EWDS) and Capacity building for coastal communities.

During disaster

Cautionary advice should be put out on social platforms urging people to stay safe. The perception of people decides the intensity of the disaster. If people take necessary proactive steps to deal with disaster then even the severe disaster can be dealt with minimum damage. Delivery of food and health care via mobile hospitals, with priorities to women child & elders. Protection of the community and their evacuation and quicker response.

Post-disaster

It is vital that the learning from each event is shared nationally, and the capacity of officials and communities to manage disasters built continuously. Among the securities available to individuals in many countries is insurance against property losses. Viable policies should be made available in India too. Providing alternative means of communication, energy and transport just after the disaster.

Odisha’s success in handling Cyclones

• In the year 1999, Odisha faced a super cyclone which took almost 15000 lives. Since then, it started to build a robust disaster management system priority basis.
• As the extremely severe cyclone Amphan inched closer, the Odisha government rolled up its sleeves and took all precautionary measures, including the evacuation of the people to meet its zero causality target.
• Just as the IMD issued the warning, the Odisha government began its cyclone preparations which included evacuation, movement of people in low-lying areas and kutcha houses to cyclone shelters, safeguarding Rabi crops in mandis, deployment of ODRAF, NDRF teams, among other measures.

Let’s learn from Odisha success Model

1. Build a relief infrastructure: Until 1999, Odisha didn’t have a well laid out plan for disaster management. Two months after the cyclone hit, the Odisha State Disaster Management Authority was set up and plans put in place. Around 900 cyclone shelters have been built in vulnerable pockets of the state, with systems in place for the evacuation of hundreds of thousands of people.

2. Accurate early warning systems: The IMD has built an effective service to predict accurate timings of cyclone formation in the Bay of Bengal and when it will make landfall along India’s coastline. This early warning system enables the state to be disaster-ready and to minimize the loss of lives. It’s then crucial that people follow the protocols in place when the warnings come in.

3. Clear communication plan: Roughly 2.6 m text messages were sent to locals in the clear language before cyclone Fani hit, keeping those potentially affected alert. Regular press briefings were made by officials to update people of the approaching cyclone. People were repeatedly advised over all forms of media not to panic and given clear “do and don’ts”. This helped in the record evacuation of 1.2 m people to safe buildings.

4. Effective co-ordination of groups

Preparations to fight the onslaught should involve a number of government agencies, as well as local community groups and volunteers working together. The government’s disaster response forces were pre-positioned in vulnerable locations, food packets for air-dropping were made ready for air force helicopters to drop to people.

5. Protecting natural defences: Mangroves as usual acted as a natural shield against the impact of cyclones and floods on the coastal areas. Activists have been fighting for the cause of natural protectors like mangroves and salt pans even as flooding incidents regularly occur in the coastal region.

Sendai Framework  (India)

Preparedness to manage disaster risks is a continuous and integrated process resulting from a wide range of risk reduction activities. The preparedness not only involves coordinated planning, and reduces duplication of disaster response efforts but also increases the overall effectiveness of such efforts. The Sendai Framework for Disaster Risk Reduction is the first major agreement of the post-2015 development agenda, with seven targets and four priorities for action. It is a 15-year; voluntary, non-binding agreement that recognizes that the state has the primary role to reduce disaster risk but that responsibility should be shared with other stakeholders including the local government, the private sector, and other stakeholders.  In cyclone disasters (like Amphan, Fani), India presented a good example of its disaster preparedness and compliance to the Sendai Framework. Zero casualty policy and the pinpoint accuracy of the IMD’s early warning system helped to reduce the possibility of deaths.

India’s improved and timely forecast for cyclones gives the government opportunity and time to prepare and manage. Better linkages between sectoral ministries and national disaster management authorities needed in countries when it comes to assessing disaster risks. It is important to acknowledge the problem beyond disaster management framing and should be framed as an adaptation need. Now the imperative for India is not only to have infrastructure that is resilient, functional and that can bounce back after a disaster, but also to have infrastructure withstand and be operational during a crisis. For this India need to employ more technology, strict following of command structure, and most importantly the participation and cooperation of local communities in the affected area.