Specq D. auteur aut IRD Bellon G. auteur aut IRD Peltier A. auteur aut IRD Lefèvre Jérôme auteur aut IRD Menkès Christophe auteur aut IRD text journalArticle eng text/pdf born digital access The relationship between the large-scale intraseasonal variability, synoptic wind regimes, and the local daily variability of precipitation over the main island of New Caledonia (southwest tropical Pacific) is investigated with a focus on the austral summer wet season (November-April). The average diurnal cycle of precipitation over the island is characterized by a sharp afternoon maximum around 1600 local time, with significant differences between the windward east coast, the leeward west coast, and the mountain range. The afternoon peak is related to the afternoon sea-breeze circulation and to the diurnal cycle of convection over land. In general, its magnitude follows the same evolution as the daily mean. In agreement with past studies, a clear modulation of the Madden-Julian oscillation (MJO) on both the diurnal cycle of precipitation and the probability of occurrence of four robust wind regimes can be identified in the New Caledonia region during the wet season. From the evidence that there is a qualitative correspondence between the effects of both the MJO phases and the wind regimes on features in the diurnal cycle of precipitation, a simple model is proposed to inspect the MJO forcing mediated by wind regimes on the diurnal variability of rain. The complete decomposition of the MJO impact shows that the modulation of diurnal cycle by the MJO relies on complex interactions between the MJO and synoptic winds that involve both large-scale MJO convective anomalies and MJO-induced modification of wind patterns. specialized CLIMAT PRECIPITATION VENT REGIME HYDROLOGIQUE RELIEF CONVECTION OSCILLATION DE MADDEN-JULIAN VARIABILITE INTRASAISONNIERE EFFET DIURNE South Pacific Ocean Madden-Julian oscillation Climate classification regimes Diurnal effects Intraseasonal variability NOUVELLE CALEDONIE PACIFIQUE 032CLIMET 148 1 333-351 2020 0027-0644 https://www.documentation.ird.fr/hor/fdi:010077770 10.1175/mwr-d-19-0177.1 0027-0644 [F B010077770] https://www.documentation.ird.fr/hor/fdi:010077770 https://www.documentation.ird.fr/intranet/publi/2020/01/010077770.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2020-02-05 2025-02-24 fdi:010077770 fre