An anthology of tropical convection: A survey of convective-dynamic synergies

Convection in the tropics appears on multiple time and space scales. One of the most difficult problems has been explaining why large-scale convection is sometimes directly related to regions of the warmest sea-surface temperature (SST) and minimum sea-level pressure while at other times there appears to be no significant collocation of the three variables.

We attempt to stratify convection in a different manner. Noting that SST is a poor correlate for the location, intensity and duration of convection, we choose, rather, a dynamic consequence of SST variations in space and time as the key. Specifically, we choose the large scale cross-equatorial pressure gradient as the stratifying agent. We find that depending upon the strength of the cross-0euqatorial pressure gradient, convection will either be directlty related to the SST maximum or be forced through dynamic porcesses to lie equatorward of the SST maximum. Through this analysis, it is possible to identify four convective-dynamic synergies within the tropics.