Reliable modeling of cloud processes for weather predictions and climate change projections requires a sound understanding of the ice formation in mixed-phase clouds. Typically, ice particles form via heterogeneous freezing of supercooled cloud droplets containing ice nucleating particles (INPs). I ce crystal concentrations measured inside the clouds are often found to exceed the concentration of INPs by many orders of magnitude. To explain this discrepancy, the Secondary Ice Production (SIP) mechanisms, i.e., processes producing multiple ice particles upon freezing of a single cloud droplet or by fragmentation of existing ice particles, must be studied.

In a DFG-funded collaborative project between the Institute of Meteorology and Climate Research (IMK) and the Leibniz-Institute for Tropospheric Research (TROPOS) in Leipzig, we are investigating two potential SIP mechanisms: production of secondary ice particles caused by (A) droplet-ice collisions (rime-splintering) and (B) splintering of freezing droplets (see Figure 1). These two SIP mechanisms have been suggested to be of particular relevance in the mixed-phase clouds.

Organizational unit

Institute of Meteorology and Climate Research Atmospheric Aerosol Research (IMKAAF)

Job description

Our Institute IMKAAF seeks a highly motivated PhD student (f/m/d) to work on the experimental investigation of droplets splintering on freezing.

The successful candidate will:

• conduct experiments with the new experimental set-up, the Ice Droplet splintEring and Fragmentation eXperiment (IDEFIX);
• participate in experiments on identification of the physical mechanisms of rime-splintering SIP events together with the leading scientists at TROPOS;
• contribute to parameterization development for both SIP mechanisms;
• take part in the measuring campaign investigating SIP in mix-phase clouds.
• The parameterizations developed as a part of this PhD project will be applied for representation of SIP mechanisms in cloud microphysics resolving models.

Starting date

01.10.2025

You have:

• A masters degree in physics, environmental physics, geophysics or meteorology
• Experimental skills and motivation to work in the lab
• Good communication skills, fluent English language in writing and speaking