Cloud Microphysics

Research group

Cloud Microphysics

Atmospheric Physics Department

Research Group Leader:

The Cloud Microphysics Research Group investigates the microphysics and dynamics of clouds across a broad range of spatial and temporal scales. The group's research encompasses processes occurring at the level of individual aerosol particles, cloud droplets, and ice crystals—including aerosol activation, condensational growth, and collision–coalescence—as well as the dynamics and evolution of entire cloud systems. Theoretical studies of turbulence and its representation in atmospheric models constitute an important component of this research.

To address these fundamental questions, the group develops and applies a Lagrangian Cloud Model (LCM), in which cloud-scale atmospheric flow computed using Large-Eddy Simulations (LES) is tightly coupled with a particle-based (Lagrangian) representation of cloud microphysical processes. This approach enables simultaneous investigation of interactions between cloud dynamics, turbulence, and microphysics across multiple scales.

Numerical Modeling and Open-Source Software

The group is internationally recognized for the development of advanced open-source software tools (https://github.com/igfuw/) designed for studying cloud microphysics and its coupling with atmospheric dynamics. These include:

libmpdata++ – a library of numerical solvers for the generalized transport equations;
libcloudph++ – a library for modeling cloud microphysics;
UWLCM (University of Warsaw Lagrangian Cloud Model) – a comprehensive LES-based cloud model built upon the capabilities of both libmpdata++ and libcloudph++.

Research Projects & Grants (Recent and Ongoing)

The group participates in numerous high-profile national and international research initiatives aimed at advancing modern atmospheric modeling methodologies. Selected examples include:

nextGEMS (Next Generation Earth Modelling Systems) – a large international project focused on developing a new generation of global Earth system models with kilometer-scale resolution capable of explicitly resolving convective and storm-related processes;
HANAMI (Horizon Europe) – a project dedicated to the development of high-performance computing (HPC) methodologies and European–Japanese collaboration in environmental and climate modeling;
National Science Centre (NCN) Grants – a series of projects investigating stochastic effects in precipitation formation, cloud dynamics and microphysics in stochastic Lagrangian models, mixed-phase cloud stability, and aerosol–cloud interactions. A suite of recent projects exploring the impact of stochastic effects on rain formation, cloud dynamics and microphysics in stochastic Lagrangian models, the stability of mixed-phase clouds, and aerosol-cloud interactions.

These projects have contributed significantly to advancing our understanding of precipitation formation, cloud evolution, and the role of clouds in weather and climate.

2026-05: Hanami blog post about our activities within the project.
2026-03: Daniel Albuquerque defends his PhD thesis Modeling particle growth by condensation and deposition in
turbulent mixed-phase cloud volumes
2025-12: Piotr Dziekan gave a talk about Adaptive condensation substepping in Lagrangian microphysics during the Hanami HLS2 in Chamonix, France.
2025-10: nextGEMS: entering the era of kilometer-scale Earth system modeling published in GMD.
2025-09: Agnieszka Makulska and Piotr Dziekan participated in the Mini-workshop on particle-based cloud modeling 2025 at the University of Hyogo, Kobe, Japan. Agnieszka gave a talk entitled "A Model Intercomparison Study of Mixed-Phase Clouds in a Laboratory Chamber" and Piotr chaired one of the sessions.
2025-09-10: Agnieszka Makulska and Piotr Dziekan visited Shima research group at the University of Hyogo, Kobe, Japan.
2025-08: A Model Intercomparison Study of Aerosol-Cloud-Turbulence Interactions in a Cloud Chamber: 1. Model Results published in JAMES.
2025-03: A First Look at the Global Climatology of Low-Level Clouds in Storm Resolving Models published in JAMES.
2025-03: Hanna Pawlowska and Piotr Dziekan participated in the nextGEMS hackathon in Stockholm, Sweden.
2025-01: Piotr Dziekan gave a talk about numerical modeling of clouds at the Fluids ZA Seminar at Faculty of Power and Aeronautical Engineering, Warsaw University of Technology.
2024-12: talk about Progress and Prospects of Lagrangian Particle-Based Cloud Modeling at the AGU Annual Meeting
2024-11: a ZFA seminar by Piotr Dziekan about modeling stratocumuli using an anisotropic turbulence model
2024-10: Piotr Dziekan participated in the nextGEMS hackathon in Wageningen, Netherlands.
2024-10: Agnieszka Makulska is enrolled for PhD studies in the Doctoral School of Exact and Natural Sciences (Physical Sciences).
2024-09: talk about Stratocumulus variability in global storm-resolving models at the EMS Annual Meeting.
2024-07: Agnieszka and Piotr participated in International Conference on Clouds and Precipitation 2024 in Jeju, South Korea. Agnieszka presented a poster about Pi chamber simulations. Piotr gave a talk about representing randomness in collision-coalescence in cloud models. Our work was also included in a poster about advances in modeling microphysics with particle-based methods.
2024-07: Agnieszka and Piotr participated in the 11th International Cloud Modeling Workshop in Seoul, South Korea. We used UWLCM to model cases C (cloud chamber simulations) and D (precipitating cumulus congestus). Agnieszka gave a talk about case C simulations.
2024-06: Agnieszka Makulska defends her MSc thesis (grade A).
2024-04: Impacts of stochastic coalescence variability on warm rain initiation using Lagrangian microphysics in box and large-eddy simulations published in JAS.
2024-04: talk about marine low-level clouds in GSRMs at EGU.
2024-01: 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 published in GMD.
2023-05: Piotr Dziekan and Jakub Nowak lead work of the SGS models group at the NextGEMS Hackathon in Madrid. A brief presentation of results can be found here.
2023-04: Piotr Dziekan's presentation at KUKDM2023 in Zakopane.
2023-01: Toward a Numerical Benchmark for Warm Rain Processes published in JAS.
2023-01: Piotr Dziekan's presentation about collision-coalescence in LES with particle microphysics at AMS2023
2022-12: Piotr Zmijewski's presentation summarizing a 2.5-month internship at RIKEN, Kobe, Japan
2022-11: Piotr Dziekan's presentation about UWLCM during NextGEMS Storms & Science hour
2022-06: University of Warsaw Lagrangian Cloud Model (UWLCM) 2.0: adaptation of a mixed Eulerian–Lagrangian numerical model for heterogeneous computing clusters published in GMD.
2022-05: our poster and short presentation won the 3rd prize at the ISC2022 conference in Hamburg
2022-04: poster about the Pi Chamber simulation intercomparison at the 16th AMS Cloud Physics conference, Madison, USA
2021-12: Impact of Giant Sea Salt Aerosol Particles on Precipitation in Marine Cumuli and Stratocumuli: Lagrangian Cloud Model Simulations published in JAS.
2021-08: Piotr Dziekan's talk about parameterization of GCCN in stratocumului at the ICCP2021 conference
2021-08: Piotr Żmijewski's poster about randomness in LES precipitation at the ICCP2021 conference
2021-07: Piotr Dziekan's talks about Pi chamber and cumulus congestus simulations at ICMW2020
2021-04: Piotr Żmijewski's presentation at the vEGU conference
2020-11: we participated in the online part of the International Cloud Modeling Workshop discussing the Pi Chamber case (recording) and the Cumulus Congestus case (recording); Piotr gave talks about modeling Cumulus Congestus with UWLCM and about giant CCN in marine clouds
2020-05: Confronting the Challenge of Modeling Cloud and Precipitation Microphysics paper published in JAMES
2020-05: Gustavo's and Piotr's talks at EGU Sharing Geosciences Online
2019-07: paper on the University of Warsaw Lagrangian Cloud Model published in GMD
2019-05: Modeling of Cloud Microphysics: Can We Do Better? paper published in BAMS
2019-04: Gustavo's and Piotr's talks at the workshop on Eulerian vs. Lagrangian methods for cloud microphysics in Kraków, Poland
2019-03: Gustavo's and Piotr's posters at the UCP2019 conference in Berlin, Germany
2019-02: defense of Maciek's PhD thesis
2019-02: paper on the University of Warsaw Lagrangian Cloud Model available for discussion in GMDD
2018-11: Gustavo's and Piotr's talks at the 2nd PBCM workshop in Kobe, Japan
2018-07: Gustavo's talk at the 15th Conference on Cloud Physics in Vancouver, Canada
2018-07: Piotr's posters (1, 2) at the 15th Conference on Cloud Physics in Vancouver, Canada
2018-06: Maciek's talk at 7th European Conference on Computational Fluid Dynamics in Glasgow, UK
2018-05: Piotr's talk at the Eulag workshop in Warsaw
2018-05: Maciek's talk at the Eulag workshop in Warsaw
2018-04: paper on third order accuracy in MPDATA published in JCP
2018-01: paper on Lagrangian condensation microphysics with Twomey CCN activation published in GMD
2017-11: paper on stochastic coalescence in Lagrangian microphysics published in ACP
2017-11: Piotr's talk at the PBCM workshop in Kobe, Japan
2017-10: Piotr's talk at the IGF seminar in Warsaw
2017-09: paper on nonlinearities in CCN activation published in NPG
2017-04: Maciek's talk at the PDEs on the sphere conference, Paris
2017-03: Ania defends her PhD thesis
2016-10: Maciek's talk at the workshop on numerical methods for geophysical flows, Reading
2016-07: Piotr's talk at the XVII ICCP in Manchester
2016-02: Hanna's talk at the UCP in Berlin
2016-01: Ania's talk at the AMS meeting on cloud chemistry in New Orleans
2015-10: group talk at the IGF seminar in Warsaw
2015-09: Sylwester's talk at a seminar at the U. of Hyogo
2015-06: libcloudph++ paper published in GMD
2015-05: Sylwester's talk at C++now
2015-05: Sylwester's talk at a seminar at the U. of Wyoming
2015-04: workshop on Eulerian vs. Lagrangian methods for cloud microphysics
2015-04: libmpdata++ paper published in GMD
2015-01: Sylwester's talk at a seminar at TUDelft
2014-10: Maciek's talk at the 4-th EULAG workshop in Mainz
2014-09: Sylwester's talk at the NCAR MMM seminar in Boulder
2014-07: Ania's poster at the AMS Cloud Physics conf. in Boston
2014-04: Dorota's talk at the UCAR Software Engineering conference in Boulder
2013-05: group talk at the IGF seminar in Warsaw

Research project

HANAMI (Hpc AlliaNce for Applications and supercoMputing Innovation: the Europe - Japan collaboration)
Source of financing: EU, HORIZON EUROPE
Realisation period: March 1, 2024–Feb. 28, 2027

Next Generation Earth Modelling Systems (NextGEMS)
Source of financing: EC, HORIZON 2020
Realisation period: Sept. 1, 2021–Aug. 31, 2025

Investigation of the stability of mixed-phase clouds based on a stochastic description of the microphysics
Source of financing: NCN, PRELUDIUM
Realisation period: Feb. 7, 2022–Aug. 6, 2024

Deterministic versus stochastic origin of warm rain
Source of financing: NCN, SONATA
Realisation period: Oct. 3, 2019–Oct. 2, 2023

Turbulent dynamics and microphysics in a Stochastic Lagrangian Cloud Model
Source of financing: NCN, OPUS
Realisation period: April 10, 2018–April 9, 2023

Untangling microphysical impacts on shallow convective clouds
Source of financing: NCN, OPUS
Realisation period: Sept. 29, 2017–Sept. 28, 2020

Numerical modeling of cloud microphysics and microphysics-dynamics interactions in shallow boundary-layer clouds
Source of financing: NCN, POLONEZ
Realisation period: Oct. 1, 2016–Sept. 30, 2017

Przetwarzanie aerozoli przez chmury - symulacje ab initio uwzględniające efekty zderzeń i reakcji chemicznych zachodzących w kropelkach chmurowych
Source of financing: NCN, PRELUDIUM
Realisation period: July 22, 2015–Jan. 21, 2017

Aerosol processing by clouds - development of a multifaceted object-oriented numerical simulation framework
Source of financing: NCN, HARMONIA
Realisation period: April 9, 2013–Jan. 8, 2017

Development of a two-dimensional kinematic numerical model of a cloud based on a precise description of microphysics of aerosol particles, clouds and rain.
Source of financing: NCN, PRELUDIUM
Realisation period: Dec. 28, 2011–June 28, 2013

prof. dr hab. Hanna Pawłowska

dr Gustavo Abade
dr Piotr Dziekan
mgr Agnieszka Makulska

Associates

prof. dr hab. Wojciech Grabowski - National Center for Atmospheric Research, Boulder, USA
prof. dr Piotr Smolarkiewicz - National Center for Atmospheric Research, Boulder, USA
dr Shin-ichiro Shima - University of Hyogo, Kobe, Japan
dr Sylwester Arabas - Akademia Górniczo-Hutnicza w Krakowie

Abade G., 2025, On Idealized Models of Turbulent Condensation in Clouds, Journal of the Atmospheric Sciences, vol. 82(8), pp. 1563-1584, 10.1175/JAS-D-24-0088.1
Chen S., Krueger S.K., Dziekan P., Enokido K., MacMillan T., Richter D., Schmalfuß S., Shima S.-I., Yang F., Anderson J.C., Cantrell W., Niedermeier D., Shaw R.A., and Stratmann F., 2025, A Model Intercomparison Study of Aerosol-Cloud-Turbulence Interactions in a Cloud Chamber: 1. Model Results, Journal of Advances in Modeling Earth Systems, vol. 17(7), art. e2024MS004562, 10.1029/2024MS004562
Grabowski W.W., Pawłowska H., 2025, Technical note: Phase space depiction of cloud condensation nuclei activation and cloud droplet diffusional growth, Atmospheric Chemistry and Physics, vol. 25(10), pp. 5273-5285, 10.5194/acp-25-5273-2025
Nowak J.L., Dragaud I.C.D.V., Lee J., Dziekan P., Mellado J.P., Stevens B., 2025, A First Look at the Global Climatology of Low‐Level Clouds in Storm Resolving Models, Journal of Advances in Modeling Earth Systems, vol. 17(3), art. e2024MS004340, 10.1029/2024MS004340
Segura H., Pedruzo-Bagazgoitia X., Weiss P., K. Müller S.K., Rackow T., ..., Dziekan P., Ekblom M., Engels J.F., Esch M., Forbes R., Frauen C., ..., Wacławczyk M., Wedi N., Wieners K.-H., Wille J., Winkler M., Wu Y., ..., Malinowski S., Martius O., Mauritsen T., Mellado J.P., Mieslinger T., Mohino E., Pawłowska H., Peters-von Gehlen K., Sarré A., Sobhani P., Stier P., Tuppi L., Vidale P.L., Sandu I., and Stevens B., 2025, nextGEMS: entering the era of kilometer-scale Earth system modeling, Geoscientific Model Development, vol. 18(20), pp. 7735–7761, 10.5194/gmd-18-7735-2025
Abade, G.C. and Albuquerque, D.G., 2024, Persistent mixed-phase states in adiabatic cloud parcels under idealised conditions, Quarterly Journal of the Royal Meteorological Society, vol. 150 (763), pp. 3450-3474, 10.1002/qj.4775
Morrison H., Chandrakar K.K., Shima S.-I., Dziekan P. and Grabowski W.W., 2024, Impacts of stochastic coalescence variability on warm rain initiation using Lagrangian microphysics in box and large-eddy simulations, Journal of the Atmospheric Sciences, vol. 81(6), 1067-1093, 10.1175/JAS-D-23-0132.1
Żmijewski P., Dziekan P., Pawłowska H., 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, Geoscientific Model Development, vol. 17(2), pp. 759-780, 10.5194/gmd-17-759-2024
Grabowski, W.W. and Pawlowska H., 2023, Adiabatic evolution of cloud droplet spectral width: A new look at an old problem, Geophysical Research Letters, vol. 50(3), art. e2022GL101917, 10.1029/2022GL101917
Hill A.A., Lebo Z.J., Andrejczuk M., Arabas S., Dziekan P., Field P., Gettelman A., Hoffmann F., Pawlowska H., Onishi R., and Vié B., 2023, Toward a Numerical Benchmark for Warm Rain Processes, Journal of the Atmospheric Sciences, vol. 80(5), pp. 1329–1359, 10.1175/JAS-D-21-0275.1
Pawlowska, H, 2023, Cloud microphysics, Postępy Fizyki, vol. 74, pp. 16-26, https://www.ptf.net.pl/sites/default/files/PF/PF_4_2023.pdf
Dziekan P., Żmijewski P., 2022, University of Warsaw Lagrangian Cloud Model (UWLCM) 2.0: adaptation of a mixed Eulerian–Lagrangian numerical model for heterogeneous computing clusters, Geoscientific Model Development, vol. 15(11), 4489–4501, 10.5194/gmd-15-4489-2022
Dziekan P., Jensen J.B., Grabowski W.W., Pawlowska H., 2021, Impact of Giant Sea Salt Aerosol Particles on Precipitation in Marine Cumuli and Stratocumuli: Lagrangian Cloud Model Simulations, Journal of the Atmospheric Sciences, vol. 78 (12), pp. 4127-4142, 10.1175/JAS-D-21-0041.1
Morrison H., van Lier‐Walqui M., Fridlind A.M., Grabowski W.W., Harrington J.Y., Hoose C., Korolev A., Kumjian M.R., Milbrandt J.A., Pawlowska H., Posselt D.J., Prat O.P., Reimel K.J., Shima S., van Diedenhoven B., and Xue L., 2020, Confronting the challenge of modeling cloud and precipitation microphysics, Journal of Advances in Modeling Earth Systems, vol. 12(8), art. e2019MS001689, 10.1029/2019MS001689
Dziekan P., Waruszewski M., Pawlowska H., 2019, University of Warsaw Lagrangian Cloud Model (UWLCM) 1.0: a modern large-eddy simulation tool for warm cloud modeling with Lagrangian microphysics, Geoscientific Model Development, vol. 12(6), 2587-2606, 10.5194/gmd-12-2587-2019
Grabowski W.W., Morrison H., Shima S., Abade G.C., Dziekan P., and Pawlowska H., 2019, Modeling of Cloud Microphysics: Can We Do Better?, Bulletin of the American Meteorological Society, vol. 100(4), 655-672, 10.1175/BAMS-D-18-0005.1
Abade, G.C., W.W. Grabowski, and H. Pawlowska, 2018, Broadening of Cloud Droplet Spectra through Eddy Hopping: Turbulent Entraining Parcel Simulations, Journal of the Atmospheric Sciences, vol. 75(10), 3365–3379, 10.1175/JAS-D-18-0078.1
Grabowski W. W., Dziekan P., and Pawlowska H., 2018, Lagrangian condensation microphysics with Twomey CCN activation, Geoscientific Model Development, vol. 11, 103-120, 10.5194/gmd-11-1-2018
Jaruga A., and Pawlowska H., 2018, ibcloudph++ 2.0: aqueous-phase chemistry extension of particle-based cloud microphysics scheme, Geoscientific Model Development, vol. 11, 3623-3645, 10.5194/gmd-11-3623-2018
Waruszewski, M., Kühnlein, C., Pawlowska, H., Smolarkiewicz, P.K., 2018, MPDATA: Third-order accuracy for variable flows, Journal of Computational Physics, vol. 359, 361-379, 10.1016/j.jcp.2018.01.005
Arabas S. and Shima S., 2017, On the CCN (de)activation nonlinearities, Nonlinear Processes in Geophysics, vol. 24, 535-542, 10.5194/npg-24-535-2017
Dziekan P. and Pawlowska H., 2017, Stochastic coalescence in Lagrangian cloud microphysics, Atmospheric Chemistry and Physics, vol. 17 (2), 13509-13520, 10.5194/acp-17-13509-2017
Grabowski W.W., Abade G.C., 2017, Broadening of Cloud Droplet Spectra through Eddy Hopping: Turbulent Adiabatic Parcel Simulations, Journal of the Atmospheric Sciences, vol. 74, 1485, 10.1175/JAS-D-17-0043.1
Arabas S., Jaruga A., Pawlowska H., and Grabowski W. W., 2015, libcloudph++ 1.0: a single-moment bulk, double-moment bulk, and particle-based warm-rain microphysics library in C++, Geoscientific Model Development, vol. 8, 1677-1707, doi: 10.5194/gmd-8-1677-2015
Jarecka D., Jaruga A., Smolarkiewicz P.K., 2015, A spreading drop of shallow water, Journal of Computational Physics, vol. 289, 53–61, 10.1016/j.jcp.2015.02.003
Jaruga A., Arabas S., Jarecka D., Pawlowska H., Smolarkiewicz P. K., Waruszewski M., 2015, libmpdata++ 1.0: a library of parallel MPDATA solvers for systems of generalised transport equations, Geoscientific Model Development, vol. 8, 1005-1032, doi:10.5194/gmd-8-1005-2015
Arabas S., Jarecka D., Jaruga A., Fijałkowski M., 2014, Formula translation in Blitz++, NumPy and modern Fortran: A case study of the language choice tradeoffs, Scientific Programming, vol. 22, 201-222, 10.3233/SPR-140379
Arabas, S., and Shima S., 2013, Large Eddy Simulations of Trade-Wind Cumuli using Particle-Based Microphysics with Monte-Carlo Coalescence, Journal of the Atmospheric Sciences, vol. 70 (9), 2768–2777, 10.1175/JAS-D-12-0295.1
Arabas S. and Pawlowska H., 2011, Adaptive method of lines for multi-component aerosol condensational growth and CCN activation, Geoscientific Model Development, vol. 4 (1), 15-31, 10.5194/gmd-4-15-2011

dr Maciej Waruszewski
dr Valerian Jewtoukoff
dr Sylwester Arabas
dr Anna Jaruga
mgr inż. Daniel Albuquerque
mgr inż. Piotr Żmijewski