The Relationship between Rain and Cloud Water as Observed from the A-train

Shallow maritime clouds are critical to regulating the climate of the Earth. Due to their warm cloud top temperatures and extensive horizontal coverage they have a larger net radiative effect at the top of the atmosphere than any other cloud type. In addition to playing a critical role in determining the radiative energy balance at the top of the atmosphere, they are also highly susceptible to environmental perturbations [1]. For example, it also proposed that their microphysics and thus albedo are highly susceptible to anthropogenic pollution [2] and observations show that their horizontal extent is largely controlled by the boundary layer inversion strength [3]. Furthermore, shallow clouds in subsidence regions also demonstrate the most uncertain response of any cloud type in their parameterization in climate models [4]. Because of the unique sensitivity and uncertainty associated with both microphysical and macrophysical processes associated with these clouds it is critical that a concerted effort be made ot enhance our current observational capabilities. In particular recent work [5] has suggested that the rainfall efficiency in these clouds is a key factor in modulating their extent and microphysics.