The North Equatorial Current and rapid intensification of super typhoons

Sok Kuh Kang; Sung-Hun Kim; I-I Lin; Young-Hyang Park; Yumi Choi; Isaac Ginis; Joseph Cione; Ji Yun Shin; Eun Jin Kim; Kyeong Ok Kim; Hyoun Woo Kang; Jae-Hyoung Park; Jean-Raymond Bidlot; Brian Ward

doi:10.1038/s41467-024-45685-2

The North Equatorial Current and rapid intensification of super typhoons

Nat Commun. 2024 Mar 7;15(1):1742. doi: 10.1038/s41467-024-45685-2.

Authors

Sok Kuh Kang¹, Sung-Hun Kim², I-I Lin³, Young-Hyang Park⁴, Yumi Choi⁵, Isaac Ginis⁶, Joseph Cione⁷, Ji Yun Shin², Eun Jin Kim², Kyeong Ok Kim², Hyoun Woo Kang², Jae-Hyoung Park⁸, Jean-Raymond Bidlot⁹, Brian Ward¹⁰

Affiliations

¹ Korea Institute of Ocean Science & Technology, Busan, Korea. skkang@kiost.ac.kr.
² Korea Institute of Ocean Science & Technology, Busan, Korea.
³ Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan.
⁴ Laboratoire LOCEAN/IPSL, Sorbonne Université-CNRS-IRD-MNHN, Paris, France. young-hyang.park@mnhn.fr.
⁵ Korea Institute of Science & Technology, Seoul, Korea.
⁶ Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, USA.
⁷ NOAA/AOML Hurricane Research Division, Miami, FL, USA.
⁸ Department of Oceanography, Pukyong National University, Busan, Korea.
⁹ European Center for Medium-Range Weather Forecasts, Reading, UK.
¹⁰ Air-Sea Laboratory and Ryan Institute, School of Natural Sciences, University of Galway, Galway, Ireland. bward@universityofgalway.ie.

Abstract

Super Typhoon Mangkhut, which traversed the North Equatorial Current (NEC; 8-17 °N) in the western North Pacific in 2018, was the most intense Category-5 tropical cyclone (TC) with the longest duration in history-3.5 days. Here we show that the combination of two factors-high ocean heat content (OHC) and increased stratification - makes the NEC region the most favored area for a rapid intensification (RI) of super typhoons, instead of the Eddy Rich Zone (17-25 °N), which was considered the most relevant for RI occurrence. The high OHC results from a northward deepening thermocline in geostrophic balance with the westward-flowing NEC. The stratification is derived from precipitation associated with the Inter-Tropical Convergence Zone in the summer peak typhoon season. These factors, which are increasingly significant over the past four decades, impede the TC-induced sea surface cooling, thus enhancing RI of TCs and simultaneously maintaining super typhoons over the NEC region.