The radiative forcing associated with aerosol-cloud interactions, traditionally referred to as aerosol indirect effects, indirectly by modifying the microphysical properties of clouds, affecting their reflectivity and persistence, contributes the largest uncertainty to total radiative forcing estimates (Boucher et al., 2013). For liquid clouds, reducing droplet size and increasing reflectance of clouds due to increased droplet number for a constant liquid water path, namely the "Twomey" effect (Twomey, 1977), is relatively well understood (Christensen et al., 2020; Diamond et al., 2020; Liu & Li, 2019). However, aerosol effects on the amount of boundary layer clouds that cover large areas of the oceans and strongly reflect incoming solar radiation are still not well-documented (Bellouin et al., 2020), especially the magnitude of the aerosol influence on cloud fraction (CF) (Ghan et al., 2016; Gryspeerdt et al., 2016). Understanding how aerosols affect cloud cover helps to reduce the considerable uncertainty of the radiative forcing associated with aerosol-cloud interactions (Fan et al., 2016) because of the strong correlation of CF to other cloud properties and their large impact on radiation. The long-term satellite observations provide excellent opportunities for quantifying cloud-mediated aerosol radiative effects (