| Wind Shear • Wind shear is defined as the change in wind speed, wind direction, or both, over some distance. • Vertical wind shear is present nearly everywhere on Earth since winds typically move faster at higher altitudes than at the surface. • Strong wind shear can offset the top of the storm. This weakens the wind circulation, as well as the transport of heat and moisture needed to fuel the storm. Result into absence of Cyclones. |
- The north Indian Ocean plays a critical role in the summer monsoon by supplying moisture through evaporation from the Arabian Sea and the Bay of Bengal.
- Despite warm tropical seas conducive to cyclone formation, this region experiences fewer cyclones due to a mix of favourable and suppressive factors.
- The Indian Ocean’s uniqueness comes from “oceanic tunnels” connecting it to the Pacific and Southern Oceans, affecting its temperatures and cyclogenesis.
- Climate change has intensified the warming of the Indian Ocean, contributing to cyclone formation during the pre- and post-monsoon seasons.
- However, the Arabian Sea remains less prone due to weaker convective activity and strong wind shear.
- The Bay of Bengal, on the other hand, sees more cyclonic systems.
- The recent rare August cyclone, Asna, emerged from a strong land-born depression transitioning to the Arabian Sea, marking the first cyclone in the north Indian Ocean in August since 1981.
- Asna caused significant damage and casualties but dissipated due to desert air.
- The event, linked to global warming and unusual weather patterns, reflects the unpredictability of the region’s climate dynamics.
Dig Deeper: Why do tropical cyclones not form over the Equator?
