Fields of convective clouds exhibit coherent weather and climate variability on time and space scales that are very large with respect to individual cumulus clouds and cloud systems. In the absence of adequate observations, this study will employ cloud resolving models to explore the sensitivity of atmospheric convection to its large-scale setting. Three hypotheses will be tested: 1.) The occurrence of deep convection has a large sensitivity to humidity in the free troposphere. 2.) The occurrence of deep convection is more sensitive to temperature anomalies in the lower than the upper troposphere. 3.) Large-scale variations of convection depend importantly on large-scale variations of the statistics of small-scale fluctuations, and not just on large-scale variations of mean conditions.
It is expected that the results from this study will usefully inform cumulus parameterization efforts in atmospheric models. The project involves the participation of a post-doctoral associate.
