DOI: 10.25338/b8sk8h
title: Data from: Limitations of separate cloud and rain categories in parameterizing collision-coalescence for bulk microphysics schemes

description: 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.
description: 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.
description: output_2M_gamma: AMP with separate cloud and rain categories, two
 moments predicted for each category output_3M_gamma:
 AMP with separate cloud and rain categories, three moments predicted for
 each category output_4M_gamma: AMP with a single liquid
 category with an assumed bimodal gamma DSD, four moments predicted for the
 category output_4M-v7: AMP with a single liquid
 category with nonparametric distributions, four moments predicted for the
 category output_6M_gamma: AMP with a single liquid
 category with an assumed bimodal gamma DSD, six moments predicted for the
 category ..._t12: Same as above except with the
 threshold bin between cloud and rain set to bin 12 (25 micron
 radius) bin_rates_cc2: contains the bin DSD library
 used to construct AMP-NP look up tables. Also contains the process rates
 (see below) corresponding to each DSD. Final Scripts:
 Contains all Matlab scripts needed to make Figures 1-9 in the
 manuscript. Folder names indicate the initial
 conditions of the unimodal gamma DSD. nu: shape parameter, N: number
 concentration, M: mass concentration. The number is an index into the
 array of values used. These arrays are nu: [1, 3, 5, 7, 9, 11, 13, 15]; N:
 [50, 100, 200, 400, 800, 1600] /cm<sup>3</sup>. M: [1, 2, 3,
 4, 5] g/kg.  cXXXXtypeX.txt files: Each line is the
 -3rd - 12th moments of the cloud and rain categories. This is diagnostic
 and available regardless of the AMP configuration. One line for each
 second of the simulation. bin.txt files: Same as above
 except for the corresponding BIN simulation.
 cparamsXXXXtypeX.txt files: Distribution parameters for each
 second. cpdfXXXXtypeX.txt files: Explicit DSD at the
 end of the timestep. Dimensions are d(mass mixing ratio)/d log diameter.
 Bin width is log(2)/3. Bin radii (cm) and masses (g) are given in
 masses_radii.mat binpdf.txt files: Same as above except
 for the corresponding BIN simulation. procrates.txt
 files: moment tendencies for moments -3rd to 9th (columns) for
 self-collection of cloud, self-collection of rain, autoconversion cloud,
 autoconversion rain, accretion cloud, accretion rain (rows). Rows repeat
 for each time step.