No decrease of tropical convection in individual deep convective systems with global warming

According to the scientific consensus, tropical convection must decrease with global warming. This decrease is manifested by a decrease of the mass transported in the upward branch of the atmospheric overturning circulation – the convective mass flux – and a connected decrease of high clouds in the tropics, with implications for climate sensitivity. By using kilometer-scale simulations in radiative-convective equilibrium and a convective tracking algorithm, we show that no such decrease occurs in storms when taken individually and that the mass transport per storm increases instead. Storms can achieve this result by aggregating more surface of the convective cores – the inner part of the storm doing the vertical transport – so that the decrease of tropical convection is actually explained by a decrease in the total number of storms. There is little variation of the mean pressure velocity in the cores of the storms, a robust finding of this study. This remarkable invariance of the mean pressure velocity points to an emerging property of convection that should receive more attention in future studies.