The PhD candidate will investigate precipitation formation processes in midlatitude and polar deep cloud systems, such as warm conveyor belts (WCBs) and atmospheric rivers (ARs) associated with the warm sectors of extratropical cyclones. The main objective is to assess conversion efficiency (i.e. the in-cloud component of precipitation efficiency), which is a key variable regulating surface precipitation. Conversion efficiency is a summary measure for all microphysical processes in clouds that determine how much of the condensate formed in clouds grows large enough to fall out as sedimenting hydrometeors.
Conversion efficiency will be quantified for different large-scale deep cloud systems in the Southern Hemisphere. A catalogue of WCBs and ARs from the past 5–10 years, spanning a wide range of conversion efficiencies, will be used to identify the microphysical and dynamical processes that control these differences. Water isotopes will serve as an integral tracer of in-cloud conversion efficiency. The project will combine existing ground-based in-situ water isotope measurements from the Antarctic East Coast with satellite-based observations from the IASI instrument aboard Metop satellites. Additional in-situ measurements will be carried out as part of the PhD. A particular focus will be set on cloud systems that impact snow accumulation (i.e. the surface mass balance) in Antarctica. For the interpretation of the observations a hierarchy of modelling tools will be used spanning from simple moist adiabatic air parcel ascent models widely used in isotope meteorology, over trajectory-based box models to complex high-resolution numerical weather model simulations.
The PhD student will work closely with members of the Cloud Dynamics team, who study complementary aspects of precipitation efficiency. The project is embedded in the Swiss Polar Institute Flagship project DOMINO (https://swisspolar.ch/spi-funding-instruments/spi-flagship-initiatives/), which focuses on key water-cycle processes affecting Antarctic surface mass balance. Extended field campaigns are planned at the Neumayer III station, operated by the Alfred Wegener Institute (AWI) in Antarctica, in collaboration with Swiss and international partners. Additional collaboration with AWI scientists will take place through the Antarctica InSync initiative (https://www.antarctica-insync.org/).

We are looking for a motivated, skilled, creative, committed and reliable person with a strong interest in dynamical meteorology. Motivation and interest in conducting field work in an extreme environment as well as in learning the skills necessary to conduct trajectory-based analyses using reanalysis data and analysing numerical model simulations from a regional isotope-enabled numerical model (COSMOiso) are essential. The basic principles of water isotope physics must be acquired and openness/curiosity for snow physics and ice core science is needed to be able to link to other research groups in DOMINO, who focus on the question: how water isotope signals of individual meteorological (extreme) events are archived in Antarctic snow and firn. Prior knowledge in tracer-based meteorological diagnostics is an advantage.
Basic programming skills or strong interest in learning to code in Python and Bash, as well as eagerness to learn how to work with large atmospheric datasets (ERA5 reanalysis and numerical weather prediction model output) is required. A Master's degree in Atmospheric and Climate Science or equivalent is indispensable; exceptions are possible if coming from a closely related field. Having attended courses in atmospheric dynamics is a significant advantage. Applicants should be fluent in written and oral English. The PhD candidate is expected to contribute to the co-supervision of BSc and MSc projects within the topical field of her/his research. Previous experience from working as an assistant for lectures or seminars is therefore an advantage.

In the Cloud Dynamics team, we wish to create a respectful and supportive environment that fosters creativity for young talented scientists to develop their own ideas. We value diversity of backgrounds and identities as an enriching and necessary aspect of research and it is our priority to make all group members feel welcome, respected and supported.
The PhD student will become part of the OCCR and the Graduate School of Climate Sciences and will thereby be a member of an important interdisciplinary network of climate scientists at the University of Bern.

Employment conditions follow the standards of the University of Bern and the SNSF for doctoral researchers.

For subject-specific questions and information about the position, please contact franziska.aemisegger@unibe.ch

Please submit a cover letter (max 1 page) including a personal statement summarising your Master Thesis and the motivation for doing a PhD in the advertised project, a CV, and a copy of the MSc degree certificate (if already available) as a single PDF file to In the cover letter please list at least two contacts that can provide letters of reference. Reference persons may be contacted but only for candidates who are invited for an interview.

The deadline for applications is , interviews will be conducted between the end of February and mid March with a planned start of the position on 1 May 2026.