Frequent cyclones in the Arabian sea might be the result of a fattening cloud of pollutants hovering over the Indian subcontinent. A new study to be published in “Nature” this week explains how the recorded anthropogenic aerosol build-up is helping violent cyclones take shape in the area.
Before the aerosol cloud appeared, it was unusual for cyclones to form, thanks to a monsoon related vertical wind shear that would virtually cut the head off developing cyclones and disintegrate them.
Over the past 30 years, these tiny pollutant particles produced on burning of fossil fuels, have amassed into what is called the ABC-Aerosol Black Clouds.
Because of its thickness, the ABC cools the surface of the sea under it, which changes the direction in which the local atmosphere moves. This change has been found to reduce the power of the wind shear that was traditionally preventing cyclones. As a result, cyclones can form on a regular basis, intensifying with the thickness of the ABC above.
Area the Arabian Sea occupies is so small that any of the cyclones forming here can reach land easily. In fact, the study claims: “more than half of all cyclones that form here make landfall.”
In recent history, large devastation in the sub continent can be attributed to cyclones from the Arabian sea: the 1998 cyclone in Gujarat killed nearly 2,900 people.