Extreme wave height response to climate modes and its association with tropical cyclones over the Indo-Pacific Ocean

Extreme wind and wave climate in the Indo-Pacific significantly induce tropical cyclones (TCs) intensity. This investigation evaluates how extreme significant wave height (SWH) and wind speed respond to natural climate variabilities, like the El Nino-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), during June-August (JJA) and September-November (SON) in the IPO region. The analysis employs the generalised extreme value distribution to assess these associations. The hourly ERA5 wind speed and SWH reanalysis data has been utilized from 1979 to 2021. The most reliable track datasets are sourced from the China Meteorological Administration (CMA) for Western North Pacific (WNP) and the India Meteorological Department (IMD) for North Indian Ocean (NIO) are used to ascertain the intensity of TCs. Further, the inter-relationships between the extreme wind-wave climate and TCs are also investigated. Significant increase in extreme SWH and wind response to independent ENSO|IOD occurs across the Bay of Bengal (BoB) and the WNP during JJA, which subsequently spreads towards the central North Pacific during SON. Additionally, the study reveals that TCs frequency is positively correlated with extreme SWH and wind speed in WNP and in BoB during JJA, while TCs intensity is associated with the ENSO and IOD.