Climate Change and Shifting Cyclone Dynamics in the North Indian Ocean

Context

Cyclonic disturbances over the North Indian Ocean, including the Arabian Sea, Bay of Bengal and adjoining land areas, have undergone significant changes over the past one century, indicating the influence of climate variability and ocean warming.

Shift in Frequency of Cyclones

Frequency Trend
. Analysis from 1900–2025 using a 10-year rolling average
. Clear inverted U-shaped pattern over the last century
. Recent decades show a decline in total disturbances

Regional Variation in Cyclonic Activity

Bay of Bengal
. Sharp decline in cyclonic disturbances in recent years
. Major contributor to overall reduction in North Indian Ocean activity

Arabian Sea
. Increasing trend in cyclonic disturbances
. Frequency still lower than Bay of Bengal, but intensity rising

Increasing Severity of Cyclones

Intensity Pattern
. Higher proportion of systems intensifying into severe cyclonic storms and above
. Reduction in numbers but increase in destructive potential

Role of Ocean Warming
. Warmer sea surface temperatures provide more energy to storms
. Arabian Sea warming faster than average, leading to stronger and less predictable cyclones

Shift in Seasonality of Cyclones

Seasonal Change
. Increasing cyclone formation during October–December
. Declining dominance of the July–September period in the Bay of Bengal

Conclusion

The North Indian Ocean is witnessing fewer but more intense cyclones, along with regional and seasonal shifts, posing enhanced challenges for disaster management, coastal planning and climate adaptation

Source : The Hindu