Opposite but comparable effects of fine and coarse aerosols on lifecycle properties of deep convective clouds

Deep convective clouds (DCCs) are crucial in the hydrological cycle and Earth’s energy budget. However, even with same meteorological conditions, continental DCC remains more, higher, and stronger than that over ocean. Here, through nine years of full-cycle tracking on tropical DCCs, the land-ocean different effect of aerosols on DCC is quantified. our observations discovered that both fine aerosols (FA, radius<1 μm) and coarse sea salt aerosols (CSA, radius>1 μm) play significant but opposing roles in the DCC development. Adding fine aerosols significantly invigorate the DCC through delaying the rain formation, increasing in total area and rainfall amount of DCC by up to 5 times at the optimal concentration of 5 µg/cm³. The fine aerosol effect contributes to the intensive DCC, frequent lightning and heavy rain event over land. In contrast, adding coarse sea salt aerosol weakens the cloud vigor and lightning by producing fewer but larger cloud drops, which accelerate warm rain at the expense of mixed-phase precipitation. Adding CSS weaken the DCC, but expanded its area by 4 times. Corresponsdingly, the lightning density is reduced by up to 90% due to the additional CSS-enhanced warm rain process. The CSS effect contributes the moderate DCC, few lightning and expansive rain event over ocean. These findings indicate that the different aerosol effects on DCC explain the land-ocean contrast on intensity and frequency of DCC.