Generally, the number of cyclones in the Bay of Bengal tends to be higher in contrast to the Arabian Sea, both of which are part of the North Indian Ocean. But a study conducted by the Indian Institute of Tropical Meteorology (IITM) in 2021 has found that the frequency and duration of tropical storms in the Arabian Sea have exponentially increased while there has been a decrease in the Bay of Bengal. The research argued that an 8% reduction has been noted in the Bay due to the decrease in humidity.
Whereas owing to the rise in sea surface temperature, global greenhouse emissions, and the weakening of wind shear have changed the dynamics of storms in the Arabian Sea. The authors state that there has been a 52% increase in the number of tropical cyclones since 2001 in the Arabian Sea while 80% increase in its duration since the 1980s.
We saw this happening since 2011
Such a conclusive argument is itself not surprising to me. As a weather enthusiast, I blogged in 2011 about the rise of major hurricanes in the Arabian Sea. A major hurricane is a tropical storm that attains category-3 or above intensity on the Saffir–Simpson hurricane.
In another post early that same year, I focused on all category-3 to above hurricanes in the Arabian Sea since meteorological record-keeping began. There were only five by then and I highlighted them to make a reason for how the Arabian Sea is changing since 1998. Before I go any further, I would like to point out that before 1998 major hurricanes were non-existent in the Arabian Sea.
Moving on, almost a decade later in 2021, I wrote another brief piece on the Arabian Sea cyclones and by this time there were 15 category-3 to above hurricanes since 1998.
To summarize my observation in a form of a chart;
(Chart by PWP)
There has been a 66.6% increase in the number of major hurricanes by 2011 since 2001. An explosive 400% uplift by 2021. If a similar trend continues, by 2031 we find that there can be a total of 45 category-3 or above hurricanes – again a 400% increase hypothetically.
This provides you with a context of how drastically the climate of the Arabian Sea has changed and all countries near the coast are in grave danger. Even if a country is not being impacted by cyclones as is the case of Pakistan, we still have seen a devastating uptick in rain intensity and duration in coastal cities.
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