Examining Convection/Large-Scale Feedbacks and Precipitation Intensification in the Tropics

It is expected that with an increasing global temperature comes an intensification of precipitation on regional scales, the so-called 'wet get wetter' phenomenon. Traditional logic would predict that this intensification scales with the Clausius Clapeyron relation of 7%K-1, however many studies have shown evidence that the extremes in precipitation can show much greater slopes. In seeking to understand this response, it is useful to examine variability on current measurable time scales. Recent work has demonstrated a regional modification of tropical convection associated with ENSO, which is observed to have a greater than Clausius-Clapeyron response to the local warming. The pattern of change follows the Gill model of heat-induced circulation and points to the importance of the interaction between convection, radiation, and dynamics in understanding climate feedbacks. To better understand these interactions, we use a cloud resolving model in radiative convective equilibrium to simulate the impact of a warm perturbation on tropical convective dynamics. The detailed model analysis will help to break apart the contributions to changes in convective precipitation, in order to help better understand the complexities in the observed super Clausius Clapeyron response to ENSO warming. This then may offer clues to help understand potential feedbacks in future large-scale warming scenarios.