The small Coriolis parameter and near-neutral convective stability in the tropics cause weak horizontal temperature gradients and weak vertical gradients in moist static energy. The circulation is assumed to have a horizontal length scale larger than individual convective systems, but small enough that the circulation is confined to the deep tropics. The model includes a warm region with active convection, a cooler region of suppressed convection, and an overturning circulation that connects the two regions and transports energy between them. They devised an energy-balance model to illustrate the feedback process as simply as possible. hypothesized that a cloud-circulation-SST feedback process could constrain the top-of-atmosphere net CRE to be uniform in the warm tropics. Thus, cloud albedo, atmospheric circulation, and SST regulate one another through negative feedbacks. Once the anvil dissipates, the sea surface warms from the renewed solar heating, and the process repeats. At this point convection fires, generating a bright anvil that shades and cools the sea surface. Within the region, the sea surface absorbs more solar energy than its surroundings, so it warms until it becomes unstable. For instance, consider how a particular region would respond to a sustained period without convection. Ramanathan and Collins argued that over the warm pool, cloud albedo, atmospheric circulation, and SST are tightly coupled through two-way interactions. The Cloud-Circulation-SST Feedback Hypothesis The results are consistent with the hypothesis that the cancelation in CRE is caused by feedbacks between cloud albedo, large-scale circulation, and SST.Ģ. This information is used to test hypotheses on why, over the warm pool, the average shortwave and longwave CRE are individually large but nearly cancel. Triggering of convection is more likely to follow a warm SST anomaly than a cold SST anomaly on timescales of several days. MCS often occur in clusters that are embedded within large westward-propagating disturbances, so shading from anvils can cool SSTs over regions spanning hundreds of kilometers. Shading from anvils causes cool anomalies in the underlying sea surface temperature (SST) of up to −0.6 ☌.

As MCS age, ice crystals in the anvil become larger, the cloud top lowers somewhat, and clouds with neutral and positive net CRE become more common. In their developing stages, MCS primarily consist of clouds that are optically thick and have a negative net cloud radiative effect (CRE). Observations from a geostationary satellite are used to describe the lifecycle of mesoscale convective systems (MCS), their associated anvil clouds, and their effects on the radiation balance over the warm pool of the tropical west Pacific Ocean.

Anvil cloud