Clara Bayley

Postdoctoral Researcher, Climate Physics Department
Max Planck Institute for Meteorology (MPI-M), Hamburg
cloud microphysics — superdroplet modelling — warm-rain processes

About

My research

I'm investigating (warm-)cloud microphysics and its implementation in climate models. In particular, I'm finding out what we can learn from the Superdroplet Method (SDM; Shima et al. 2009) about rain formation in tropical shallow cumulus.

My focus is on deciphering if our fundamental theories of cloud microphysics, as modelled by SDM, can explain the macrophysical properties of precipitation and shallow cumulus cloud patterns — i.e. properties which we can actually observe "in the field". To do this I created a SDM called Cleo, which I am currently using in idealised simulations to test the convergence properties of SDM (with increasing number of superdroplets, for example), as well as Cleo's computational efficiency.

If you are interested in my research, want to conduct a project, or collaborate with me, please feel free to contact me!

Cleo

Cleo — new superdroplet model for high computational performance

Cleo is an open-source superdroplet model in C++/Kokkos designed to run efficiently on high-performance computers. It's flexibly designed to model all the major warm-cloud microphysical processes — condensation/evaporation, droplet collisions and their motion — and is easily extendable beyond warm clouds.

You can find out more about Cleo from its website and model description papers.

yoctoyotta1024 / CLEO

github.com/yoctoyotta1024/CLEO →

Lagrangian super-droplet model for warm-cloud microphysics, written in C++ with Kokkos for performance-portable HPC. Open source under BSD-3-Clause; documentation and build instructions at yoctoyotta1024.github.io/CLEO.

C++ / Kokkos Python bindings BSD-3-Clause HPC-ready Lead developer

Bayley, C. J. A., Naumann, A. K., Poydenot, F., Vogel, R., Stevens, B., Shima, S.-I. — Cleo: the numerical methods of a new superdroplet model including a droplet breakup algorithm (v0.52.0)

GMDGeosci. Model Dev., 19, 6121–6142 · doi:10.5194/gmd-19-6121-2026

Bayley, C. J. A., Kölling, T., Naumann, A. K., Vogel, R., Stevens, B. — Cleo: the fundamental design of a new superdroplet model for high computational performance (v0.39.0)

GMDGeosci. Model Dev., 19, 6099–6120 · doi:10.5194/gmd-19-6099-2026

Publications

Selected papers & preprints

  • In prep.
    Bayley, C. J. A., Ware, E., Arabas, S. — SDM as a Numerical Benchmark for Warm-Rain Processes?
  • In prep.
    Windmiller, J., Groß, S., Stevens, B., Ament, F., Mayer, B., Wendisch, M., Wu, Y., et al. incl. Bayley, C. J. A.PERCUSION's contribution to ORCESTRA
  • 2026
    Bayley, C. J. A. & Niebaum, N. (equal contribution), Poydenot, F., Naumann, A. K., Sarkar, M., Vogel, R. — Constraining Rain Evaporation from Shallow Clouds in the Trades using an Observation-Based Superdroplet Model
    PreprintEGUsphere · doi:10.5194/egusphere-2025-5551
  • 2026
    Bayley, C. J. A., Naumann, A. K., Poydenot, F., Vogel, R., Stevens, B., Shima, S.-I. — Cleo: the numerical methods of a new superdroplet model including a droplet breakup algorithm (v0.52.0)
    GMDGeosci. Model Dev., 19, 6121–6142 · doi:10.5194/gmd-19-6121-2026
  • 2026
    Bayley, C. J. A., Kölling, T., Naumann, A. K., Vogel, R., Stevens, B. — Cleo: the fundamental design of a new superdroplet model for high computational performance (v0.39.0)
    GMDGeosci. Model Dev., 19, 6099–6120 · doi:10.5194/gmd-19-6099-2026
  • 2026
    Bayley, C. J. A.Design and First Applications of Cleo, a Flexible Superdroplet Model for Warm-Cloud Physics on High-Performance Computers
    PhD ThesisMax Planck Institute for Meteorology, Hamburg · doi:10.17617/2.3717814
  • 2025
    Segura, H., Bayley, C. J. A., et al. — A single tropical rainbelt in global storm-resolving models: the role of surface heat fluxes over the warm pool
    JAMESJ. Adv. Model. Earth Syst., 17, e2024MS004897 · doi:10.1029/2024MS004897
  • 2023
    Kasoar, M., Bayley, C. J. A., Wells, C., Voulgarakis, A. — A Negative Feedback on El Niño Events Caused by Extreme Fire Activity in Equatorial Asia
    PreprintResearch Square · doi:10.21203/rs.3.rs-2770952/v1

Full list and citation metrics on Google Scholar · verified record on ORCID 0000-0002-4540-9382

Academic Record

Positions & education

Download full CV (PDF)

Resources

Tools & tutorials I've found useful

An eclectic selection of references for new students and research software engineers

Coding resources
Climate research tools

Contact

Get in touch

Happy to hear from prospective collaborators, students, or others generally interested!

Pronouns: she/her