A study of upper ocean characteristics in response to the three intense re-curving tropical cyclones from the Arabian Sea using satellite and in situ measurements

• Published in: Oceanologia 2024, Vol.66 (4)
• Main Authors: Dube, Adarsh, Maurya, Ajeet Ku, Singh, Rajesh, Dharmaraj, T
• Format: Article
• Language: English
• ISSN: 0078-3234; 2300-7370
• DOI: 10.5697/VIVV8745

We present the sea surface temperature (SST), latent heat flux (LHF), and sensible heat flux (SHF) studies of three tropical cyclones in the Indian subcontinent region. These three tropical cyclones were scrutinized based on their intensity scale ranging from Category 2 (Very Severe Cyclonic Storm, VSCS) to Category 5 (Super Cyclonic Storm, SuCS) on a hurricane scale (IMD scale). VSCS Vayu, SuCS Kyarr, and ESCS (Extremely Severe Cyclonic Storm) Maha formed over the Arabian Sea in June, October, and November 2019, respectively. There is a 2∘C to 4∘C difference in the SST during the pre- and post-cyclone period along the best track. The maximum reductions in SST up to 8∘C have occurred in the region from where the cyclones have re-curved. The enthalpy fluxes (LHF and SHF) are highest at 280 W/m2 around the cyclone’s best track and follow the same direction of the cyclone development. Prior flux changes in the cyclone region may have a role in directing the cyclone’s best track. Argo floats within 1∘ from the best track revealed that pre-cyclone SST was warmer at the surface than post-cyclone SST. The sub-surface SST at a depth of 100–150 m suggests a warming of the ocean in the post-cyclone period near and adjacent to cyclone intensification regions due to the upwelling of the warm subsurface waters. The upper ocean response is crucial to studying the increasing intensity of TCs and the re-curvature of its best track over the Arabian Sea.