Influence of the Madden-Julian Oscillation (MJO) on Tropical Cyclones Affecting Tonga in the Southwest Pacific
Authors:Tu'uholoaki, Moleni Espejo, Antonio Sharma, Krishneel K. Singh, Awnesh Wandres, Moritz Damlamian, Herve Chand, Savin
Volume:14
Published:2023
Document Type:Article
Abstract:The modulating influence of the Madden-Julian oscillation (MJO) on tropical cyclones (TCs) has been examined globally, regionally, and subregionally, but its impact on the island scale remains unclear. This study investigates how TC activity affecting the Tonga region is being modulated by the MJO, using the Southwest Pacific Enhanced Archive of Tropical Cyclones (SPEArTC) and the MJO index. In particular, this study investigates how the MJO modulates the frequency and intensity of TCs affecting the Tonga region relative to the entire study period (1970-2019; hereafter referred to as all years), as well as to different phases of the El Nino southern oscillation (ENSO) phenomenon. Results suggest that the MJO strongly modulates TC activity affecting the Tonga region. The frequency and intensity of TCs is enhanced during the active phases (phases six to eight) in all years, including El Nino and ENSO-neutral years. The MJO also strongly influences the climatological pattern of genesis of TCs affecting the Tonga region, where more (fewer) cyclones form in the active (inactive) phases of the MJO and more genesis points are clustered (scattered) near (away from) the Tonga region. There were three regression curves that best described the movement of TCs in the region matching the dominant steering mechanisms in the Southwest Pacific region. The findings of this study can provide climatological information for the Tonga Meteorological Service (TMS) and disaster managers to better understand the TC risk associated with the impact of the MJO on TCs affecting the Tonga region and support its TC early warning system.
Author Information
Corresponding Author:Tu'uholoaki, M (corresponding author), Univ South Pacific, Pacific Ctr Environm & Sustainable Dev, Suva, Fiji.;Tu'uholoaki, M (corresponding author), Tonga Meteorol Serv, Nukualofa, Tonga.
Reprint Address:Tu'uholoaki, M (corresponding author), Univ South Pacific, Pacific Ctr Environm & Sustainable Dev, Suva, Fiji.;Tu'uholoaki, M (corresponding author), Tonga Meteorol Serv, Nukualofa, Tonga.
Addresses:[Tu'uholoaki, Moleni; Singh, Awnesh] Univ South Pacific, Pacific Ctr Environm & Sustainable Dev, Suva, Fiji; [Tu'uholoaki, Moleni] Tonga Meteorol Serv, Nukualofa, Tonga; [Espejo, Antonio; Wandres, Moritz; Damlamian, Herve] Pacific Community, Geosci Energy & Maritime Div, Suva, Fiji; [Sharma, Krishneel K.; Chand, Savin] Federat Univ, Ctr New Energy & Transit Res, Mt Helen Campus, Mt Helen, Vic, Australia
E-mail Addresses:s11182388@student.usp.ac.fj; antonioh@spc.int; k.sharma@federation.edu.au; awnesh.singh@usp.ac.fj; moritzw@spc.int; herveda@spc.int; s.chand@federation.edu.au