Understanding clouds and precipitation over the Mount Qomolangma: how does the aerosol activation effect exist?

Can the "Roof of the world" Mount Qomolangma (MQ) serve as a "natural laboratory" for the activation effect of aerosols on the cloud-precipitation process? Here, we carried out the vertical observations of aerosols, clouds, and precipitation at the MQ, where the dual-radar active remote sensing technique is integrated with precipitation observation for the first time. It is found from the observational study that during the Indian summer monsoon, aerosols from South Asia have a distinct activation effect on the cloud-precipitation process over the MQ. Under dynamic lifting, the increase in aerosols, which inhibits and delays weak precipitation over the MQ, instead intensifies the development of clouds over the MQ, leading to heavy precipitation on the north slope. The synergy of the MQ thermal-dynamic driving mechanism and the aerosol activation effect can trigger the deep convection in the precipitation process on the north slope of the MQ. Cloud development is more intense with the aerosol activation effect, and the diurnal cycle of convective clouds in the vertical change over the MQ presents a lag response to changing aerosols. From the perspective of climate impact on interannual variations, it can also be found that the frequency of light rain over the MQ present the significantly decreased trend, while the frequency of moderate to heavy precipitation on the north slope has a significantly increased trend, revealing the differentiated changes in the precipitation on the south and north slopes of the MQ under the influence of the aerosol activation effect on the cloud-precipitation process.