Mesoscale convective systems (MCSs) downstream of the Tibetan Plateau (TP) exhibit unique precipitation features. These MCSs can have damaging impacts and there is a critical need for improving the representation of MCSs in numerical models. However, most global climate models are typically run at resolutions that are too coarse to reasonably resolve MCSs, and it is still unclear how well higher-resolution global models can reproduce the precipitation characteristics of MCSs. In this study, the sensitivity of MCSs simulated by a global high resolution (~ 10 km), atmosphere-only climate model to different treatments of convection (with and without parametrized convection, and a hybrid representation of convection) have been investigated. The results show that explicit convection (i.e., non-parameterized) can better reproduce the observed pattern of MCS precipitation over the East Asian Summer Monsoon region. In general, explicit convection better simulates the diurnal variability of MCSs over the eastern China, and is able to represent the distinctive diurnal variations of MCS precipitation over complex terrain particularly well, such as the eastern TP and the complex terrain of central-northern China. It is shown that explicit convection is better at simulating the timing of initiation and subsequent propagating features of the MCS, resulting in better diurnal variations and further a better spatial pattern of summer mean MCS precipitation. All three experiments simulate MCS rainfall areas which are notably smaller than those in observations, but with much stronger rainfall intensities, implying that these biases in simulated MCS morphological characteristics are not sensitive to the different treatment of convection.

青藏高原（TP）下游的中尺度对流系统（MCS）表现出独特的降水特征。这些 MCS 可能会产生破坏性影响，因此迫切需要改进 MCS 在数值模型中的表示。然而，大多数全球气候模型通常以过于粗糙的分辨率运行，无法合理解析 MCS，目前尚不清楚更高分辨率的全球模型在多大程度上再现了 MCS 的降水特征。在这项研究中，研究了通过全球高分辨率（约 10 公里）、仅大气气候模型模拟的 MCS 对不同对流处理（有和没有参数化对流，以及对流的混合表示）的敏感性。结果表明，显式对流（即，非参数化）可以更好地再现东亚夏季风区 MCS 降水的观测模式。总体而言，显性对流较好地模拟了华东地区MCS的日变化，尤其能够较好地反映高原东部、华中-华北复杂地形等复杂地形上MCS降水的日变化特征。结果表明，显式对流能更好地模拟 MCS 的起始时间和随后的传播特征，从而产生更好的日变化，并进一步改善夏季平均 MCS 降水的空间格局。所有三个实验都模拟了 MCS 降雨区域，这些区域明显小于观测值，但降雨强度要强得多，