Observational validation of the compensating mass flux through the shell around cumulus clouds

The existence of a subsiding shell around cumulus clouds has been observed before in several aircraft measurement campaigns. Recent results from large-eddy simulations (LES) pointed out that the downward mass flux through the shell compensates a significant fraction of the upward mass flux through the cloud. In this study, airplane measurements from the Rain In Cumulus over the Ocean (RICO) field campaign are used to verify this compensating mass flux. Just like in the LES results, the in-shell downward mass flux is found to be significant. However, a few differences were found in comparison with the LES results; most of them were explained by taking into account the difference between the 2-dimensional slabs in LES and the 1-dimensional lines from airplane observations.