Limitations of separate cloud and rain categories in parameterizing collision-coalescence for bulk microphysics schemes

Warm rain collision coalescence has been persistently difficult to parameterize in the bulk microphysics schemes used by weather forecast models, climate models, and higher resolution models of the atmosphere. The Arbitrary Moment Predictor (AMP) has been run in a variety of configurations for collision-coalescence to investigate reasons for the difficulty. The simulations suggest that the primary reason traditional bulk schemes struggle with warm rain formation is the use of separate cloud and rain categories. When the drop size distribution is represented a single bimodal distribution rather than two separate unimodal distributions, the simulation of cloud-to-rain conversion is substantially improved. This dataset contains all of the simulation output and scripts required to reproduce the results in the manuscript that support these conclusions.

Methods
This dataset was produced by running AMP. AMP is described in Igel (2019, https://dx.doi.org/10.1029/2019MS001733) and in the current manuscript.