The intrusion of spicy water favours the intensification of Arabian Sea cyclones

Abstract

The intensity of the cyclones in the Arabian Sea has been increasing in recent years. Approximately ten storms were intensified into severe cyclones over spicy waters of the northern Arabian Sea during 1998-2019. Reduction in upwelling was observed due to decreasing wind speed, which raised the sea surface temperature (SST) and the intrusion of spicy waters from the Red Sea and the Persian Gulf acted as a barrier to mixing in the top layers, especially in May. Consequently, there was a noticeable increase in the heat content of the 50 m surface layer. This research presents two main rationales that explain the intensification of these cyclones. The first rationale explores the increasing trends in SST and ocean internal energy, while the second investigates the influence of the intrusion of spicy Persian Gulf waters into the Oman coast. The results showed that spicy water from the north suppressed the upwelling in the cold core eddy off the Oman coast and that higher SSTs and high latent heat flux almost double the climatological values off the Oman coast in May.