Bay of Bengal: Urgent Warning of Catastrophic Cyclones

Bay of Bengal is the north-east part of The Indian Ocean and has been known to produce severe and deadly cyclones, It is responsible for killing people and damaging the property, livelihood in the coastal region of India, Bangladesh, Myanmar, and Sri lanka which have severe impacts on their economy. Credit: Chaitanya Mallapur/Getty Images To understand why the Bay of Bengal is more susceptible to cyclones than many, one needs to get into the nitty-gritty of meteorological, geographical and oceanographic reasons.

Bay of Bengal: Geographical and climate Background

To its east and southeast the partaitogel Bay of Bengal is bounded by the Andaman and Nicobar Islands, an archipelago of no fewer than 300 islands which historically have lost some or all of their anthropogenic forest cover because of commercial activities of controv ersial nature. That means, its geographical position that makes it prone to cyclones. Tropical cyclones often develop with warm sea surface temperatures and high humidity in the region’s tropical climate. The seasonal monsoons only exacerbate these conditions, fluctuating different atmospherical pressures between the air masses and change of wind direction.

Role of SST (Sea Surface Temperatures)

High Sea Surface Temperatures (SSTs): This is one of the main reasons for the regular cyclones over the Bay of Bengal. THE SSTs MUST BE AT LEAST 26.5 DEGREE CELCIUS, FOR A CYCLONE TO ORIGIN FORM THIS AREA. The Bay of Bengal experiences temperatures above this threshold very regularly, particularly during the pre-monsoon (April to June) and post-monsoon (October to December) seasons.

This is because warm waters add the heat and moisture needed to power the cyclone, ultimately leading to their creation of these well-defined low- pressure systems. Such local systems, powered by the rotation of the earth and the increased gravitational pull of the sea, Small Ocean basins can become rotational, and if other atmospheric conditions are favorable, even more rotation can be cyclical.

Monsoonal Influences

The Indian Ocean, especially the Bay of Bengal, is dominated by the Indian monsoon system. This is caused by the southwest monsoon, which takes place between June and September when the humid air from the Indian Ocean leads to more frequent storms and heavy monsoon rainfalls as the humidity rises. During this time, the intertropical convergence zone moves northward to the Arabian Sea and land-based temperature differences increase to their summer monsoon levels.

Even though the south-west monsoon does not typically generate cyclones, the withdrawal phase of monsoon (north-east monsoon) between October and December is more favourable for the development of cyclones. As the winds change their path and the pressure patterns change so rapidly, this changing wind then leads to the formation of cyclonic storm.

The Madden-Julian Oscillation — The Reason

Madden-Julian Oscillation (MJO) is one of the key parameters which provides significant influence on the mode of planetary-scale intraseasonal variations in the Bay of Bengal cyclone activity. It essentially is a pulse of cloudiness and rainfall floats eastward along the equator on average every 30-60 days. As it propagates across the Indian Ocean, the active phase of the MJO promotes convection, and subsequently, cyclone formation. During the post-monsoon period, the MJO can also influence the weather to a high degree, adding to the numerous cyclones in the region.

Atmospheric Conditions

Before forming, and during its presence, many atmospheric conditions need to conspire together for a cyclone to strengthen and sustain itself. Warm sea surface temperatures are not only another critical factor, but low vertical wind shear as well. Wind shear is the change in wind speed and direction with height. Strong wind shear destroys the organisation of a developing cyclone, however, so disrupts intensity.

The Southern Hemisphere and South-east Indian Ocean regions such as the Bay of Bengal, face low wind shear during the cyclone seasons providing an opportunity for these systems to develop and mature. Moreover, It requires a pre-existing disturbance for example a low-pressure system, to start off the cycle of cyclone formation.

Geography: topographical and coastal features

The topography and coastal features of the surrounding regions also adds to unique characteristics of cyclones in the Bay of Bengal. The storm surges of the northern bay side are particularly amplified due to the funnel-shaped coastline around Bangladesh.

With strong cyclones passing overhead, the shrinking coastline concentrates this water, raising the levels of the storm surges and increasing the amount of destruction. Furthermore, its coastal regions (where over half the population lives) are highly impacted by both flooding and wind, creating significant potential for humanitarian disasters with these storms.

Patterns Over Time and the Year

The Bay of Bengal is famous for the worst cyclones in world history. Its history is one of the most storm-scarred parts of the world, with some of the most violent, killer cyclones in history hitting here. For example, one of the deadliest natural disaster still to this day is the 1970 Bhola cyclone in Bangladesh, which is believed to have killed 300, 000- 500, 000 people.

This disastrous event underscored just how exposed this population was to the range of hazards cyclones could induce in the region. While scientific advances and better early warning systems have significantly minimised the dangers posed by cyclones over the decades, the inherent risk from these storms is still huge.

Climate change and its consequences

Cyclones from over the Bay of Bengal, forecast to increase in both number and intensity with climate change. Global Warming, may be able to promote an increase in sea surface temperature and consequently an intensification and a higher frequencx of ocurrences of cyclonic activities. Sea-level rise also poses a major threat to coastal communities, making storm surges and flooding even worse. While the specific regional influences of climate change on cyclone patterns are still being studied, it is certain that the Bay of Bengal will continue to face vulnerabilities to these disasters into the foreseeable future.

Methods for Mitigation and Adaptation

As cyclones have a high probability of occurrence in the Bay of Bengal, effective mitigation and adaptation strategies become key in reducing its footprint. A good way to mitigate the effects of loss is to have an early warning system, improved forecasting techniques and a well thought out disaster preparedness systems, as part of a multi pronged approach to deal with the unexpectedness of natural disasters.

Coastal cities should invest more in cyclone shelters, embankments, and resilient housing, which will drastically decrease loss of life and property and subsequently allow for quick and more effective rehabilitation phases. Furthermore, Community based disaster preparedness programs on cyclone threat mitigation help in strengthening community resilience and timely and effective responses.

Conclusion

The Bay of Bengal, known for its periodic susceptibility to cyclones, involves a complex interaction of geographical, meteorological, and oceanographic conditions. These are just a few of the reasons why there is such high cyclone activity in this region, as it all helps in creating the warm SSTs, perfect atmospheric environment, monsoonal impacts, and the MJO that lead to highly conducive areas for their formation.

These trends, when taken with the evidence of climate change, in addition to trends that are certain to continue, demand that we conduct further careful research in combination with a move towards better forecasting tools and more effective mitigation strategies to reduce heat-related mortality in this at-risk population of one of the most vulnerable regions in the world.

The lives of future generations can be saved, and their livelihood assured, by managing these root causes and developing strong adaptation coping strategies to fight the destruction caused by the Cyclones of the Bay of Bengal. If you like reading this article, please consider reading our article about Bento.

About The Author

Benjamin Smith