Climate control of tropical cyclone rapid intensification frequency in the north indian ocean

Abstract Rapid intensification (RI ≥ 20 knots/24h) is essential to very severe cyclonic storm (VSCS) in the North Indian Ocean (NIO). Between 1980 and 2020, annual numbers of VSCSs were strongly correlated with RI-20 events during pre-monsoon (April-June) post-monsoon (October-December) periods Arabian Sea (ARB) Bay Bengal (BoB). Singular value decomposition (SVD) analysis was applied sea surface temperature (SST) number RI seasons. The leading SVD mode explained ∼85% (83%) total covariance (post-monsoon). With an increase SST, increased ARB BoB pre-monsoon, enhanced but reduced post-monsoon. Decreased vertical wind shear primary contributor pre-monsoon. During post-monsoon, decreased relative humidity contributed ARB, while absolute vorticity BoB. These results suggest occurrence both seasons (decreased) (post-monsoon) increasing SST.