Given vigorous mean diurnal variation (MDV) of cumulus convection and surface wind over coastal waters of the Indonesian Maritime Continent, surface sensible and latent heat fluxes (SHF and LHF) are expected to also exhibit significant MDV. However, it is difficult to grasp characteristics of MDV of these fluxes due to lack of surface observation data. Recently, two intensive observation campaigns were conducted off the west coast of Sumatra Island in austral summer, which offer us a unique opportunity to examine the characteristics of convection and the fluxes. This study analyzes these observations to reveal that the MDV of both SHF and LHF has considerable amplitude compared with the average. The MDV of SHF is primarily caused by that in surface air temperature, which is due to the MDV of convection. As for LHF, the MDV is primarily caused by that of surface wind speed, in which both the MDV of convection and sea/land breezes play roles. Furthermore, there are qualitative differences in the MDV of the fluxes between the two campaign periods, which can be explained from the viewpoint of differences in phase and intensity of MDV of convection and the sea/land breezes.

鉴于印度尼西亚海陆沿岸积水的强对流平均日变化（MDV）和地表风，预计表面感热通量和潜热通量（SHF和LHF）也将表现出显着的MDV。然而，由于缺乏表面观察数据，难以掌握这些通量的MDV特性。最近，在南方夏季，在苏门答腊岛西海岸附近进行了两次密集的观测活动，这为我们提供了一个独特的机会来检查对流和通量的特征。这项研究分析了这些观察结果，发现SHF和LHF的MDV与平均值相比具有相当大的幅度。SHF的MDV主要是由地面空气温度引起的，这是由于对流的MDV引起的。至于LHF，MDV主要是由地表风速引起的，对流和海/陆风均在其中发挥作用。此外，两个运动周期之间通量的MDV存在质的差异，这可以从对流和海陆风的MDV的相位和强度的差异来解释。