Topic of the Day – Bomb Cyclones

Bomb cyclone is a concept in Geography that was recently seen in the news. Hence, it is important to know what it means for the IAS exam. In this article, you can read about bomb cyclones for the UPSC geography section.

Bomb cyclone is actually used by meteorologists to indicate a mid-latitude cyclone that intensifies rapidly. It is a massive winter storm hammering the coast, bringing strong winds, flooding, ice and snow. It is a combination of rapidly declining pressure and extreme cold. This particular storm is the most explosive ever, observed on the east coast. It is called bomb cyclone, a dramatic name for what happens when the storm explosively strengthens while the pressure plummets.

Bombing out, “bombogenesis” or “explosive cyclogenesis” is a phenomenon when a cyclone’s central pressure drops 24 millibars or more in 24 hours time. Cold arctic air colliding with warm ocean water is a common source of this collision. Thus, it is a midlatitude cyclone which gains strength from an extreme drop in atmospheric pressure. This brings out furious winds that can quickly create blizzard conditions and coastal flooding. The lower the pressure is, the stronger the storm. They are also popularly called by other names, such as the Nor’easter cyclone and the mid-latitude cyclone.

This sort of winter hurricane gets formed because of the occurrence of events by chance, like the convergence of several factors, including a blast of freezing air from the North Pole that, right off the southeast coast of the United States, that comes into contact with warm ocean waters carried by the Gulf Stream. When the pressure of the storm rapidly falls down, it drives stronger winds as the winds try and blow in order to equalize the differences in the pressure. Due to the difference in pressure and unstable atmosphere, the wind starts to flow from the high pressure to the low pressure. This balances out the difference or instability in the atmosphere. The direction is counterclockwise in the Northern hemisphere leading to winds that come out of the northeast. The other unusual thing about this bomb cyclone is that it’s farther south than normal.

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