Climate Change

What is a ‘bomb cyclone’?

Bomb cyclones could become much more frequent in the near future due to human-emitted greenhouse gases

By DTE Staff
Published: Wednesday 28 December 2022

A storm named Elliot has taken the lives of more than 30 people and affected around 250 million people across the US and Canada. But this is not an ordinary storm. It’s a ‘bomb cyclone’.

Normally, in a storm wind flows from high pressure areas into low pressure areas. But, when the pressure drops in the low pressure areas by ‘24 millibars’ in 24 hours, then it rapidly intensifies the difference between the two air masses strengthening the winds that flow — this process is called ‘bombogenesis’.

Elliot has wreaked havoc over 3,000 kilometres right from Mexico to Canada. It began as a low-pressure system close to the Rocky Mountains in North America, around December 21, 2022.

It intensified rapidly and turned into a bomb cyclone within 24 hours. The rapid intensification was caused by a polar jet stream across the Arctic region which brought the cold air to the far south to interact with the low pressure area formation.

On December 23, Buffalo city in New York state recorded 566.4 millimetres of snowfall. The previous record of highest daily snowfall was 320 mm in 1976. The city also recorded 50.2 mm of rainfall, the highest daily rainfall in Buffalo in 144 years. The previous record was 43.9 mm in 1878.

The Arctic region is warming much faster than the rest of the world. This is ‘lowering’ the ‘albedo effect’ such that sunlight is being absorbed into the Earth’s surface rather than being reflected back.

This is weakening the polar jet stream, which is undulating much more than before creating conditions that are more favourable for the formation of bomb cyclones.

Additionally, with human-emitted greenhouse gases, such events could become much more frequent in the near future. Conditions are likely to improve in eastern and mid-western United States and southern Canada from December 26.

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