Relationship between diurnal convection and the intraseasonal oscillation (ISO) over the western Maritime Continent (MC) was investigated by a case study of an ISO event that occurred during the Years of the Maritime Continent (YMC)-Sumatra 2017 campaign. Two sets of global cloud-permitting simulations using cloud microphysics settings for ISO prediction (CTL) and for climate simulation (MOD) were performed to clarify their impacts. CTL had biases of weaker diurnal variation and smaller precipitation amounts over land than in observations; these were reduced in MOD by higher probabilities of local intense convection in the middle troposphere and higher precipitation efficiency. The enhanced convection over land coincided with suppressed convection over the surrounding ocean, especially at the diurnal peak time of land convection. Exception is the onset period of the ISO convection, when upward moisture advection and precipitation increased also over ocean in MOD than in CTL at the diurnal peak time of oceanic convection. These results suggest that the enhancement of local convection over the MC by the cloud microphysical processes basically hinder the ISO convection by the activation of land convection, but it also favors the ISO convection development over ocean during the onset period.

通过对海事年（YMC）-苏门答腊2017年运动期间发生的一次ISO事件进行案例研究，调查了西部海事大陆（MC）的昼夜对流与季节内振荡（ISO）之间的关系。为了阐明它们的影响，进行了两组使用云微物理设置的全球云许可模拟，用于ISO预测（CTL）和气候模拟（MOD）。与观测值相比，CTL的日变化偏弱，降水量较小。由于对流层中部局部强烈对流的可能性较高，降水效率较高，因此降低了这些。陆地对流的增强与周围海洋对流的抑制同时发生，特别是在陆地对流的昼夜高峰期。ISO对流的开始期是例外，在海洋对流的每日高峰期，MOD中海洋向上的水分对流和降水也比CTL中的向上增加。这些结果表明，云微物理过程对MC的局部对流的增强基本上通过陆地对流的激活而阻碍了ISO对流，但也有利于在发病期间海洋上的ISO对流发展。