Modeling collision–coalescence in particle microphysics: numerical convergence of mean and variance of precipitation in cloud simulations using the University of Warsaw Lagrangian  Cloud Model (UWLCM) 2.1

Zmijewski, Piotr; Dziekan, Piotr; Pawlowska, Hanna

doi:https://doi.org/10.5194/gmd-17-759-2024

Articles | Volume 17, issue 2

https://doi.org/10.5194/gmd-17-759-2024

© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue:

Particle-based methods for simulating atmospheric aerosol...

https://doi.org/10.5194/gmd-17-759-2024

© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 17, issue 2

Model evaluation paper

|

30 Jan 2024

Model evaluation paper |

| 30 Jan 2024

Modeling collision–coalescence in particle microphysics: numerical convergence of mean and variance of precipitation in cloud simulations using the University of Warsaw Lagrangian Cloud Model (UWLCM) 2.1

Piotr Zmijewski, Piotr Dziekan, and Hanna Pawlowska

Supplement

https://doi.org/10.5194/gmd-17-759-2024-supplement

Data sets

Data and scripts accompanying the paper "Modeling Collision-Coalescence in Particle Microphysics: Numerical Convergence of Mean and Variance of Precipitation in Cloud Simulations Using University of Warsaw Lagrangian Cloud Model (UWLCM) 2.1" P. Zmijewski et al. https://doi.org/10.5281/zenodo.7685538

Model code and software

University of Warsaw Lagrangian Cloud Model v2.1 source code P. Dziekan et al. https://doi.org/10.5281/zenodo.7643309

libmpdata++ v2.1 source code S. Arabas et al. https://doi.org/10.5281/zenodo.7643674

libcloudph++ v3.1 source code S. Arabas et al. https://doi.org/10.5281/zenodo.7643319

UWLCM plotting v1.0 source code P. Dziekan and P. Zmijewski https://doi.org/10.5281/zenodo.7643747

Coal Fluctu v2.2 source code P. Dziekan https://doi.org/10.5281/zenodo.10076329

igfuw/synth\_turb: Initial release P. Dziekan https://doi.org/10.5281/zenodo.8270196

Short summary

In computer simulations of clouds it is necessary to model the myriad of droplets that constitute a cloud. A popular method for this is to use so-called super-droplets (SDs), each representing many real droplets. It has remained a challenge to model collisions of SDs. We study how precipitation in a cumulus cloud depends on the number of SDs. Surprisingly, we do not find convergence in mean precipitation even for numbers of SDs much larger than typically used in simulations.