As part of the ongoing MOSAiC field campaign in the high Arctic (http://mosaic-expedition.org) the Polarstern Research Vessel is currently making unprecedented measurements of low level turbulence, clouds and radiation in the Arctic Mixed Layer (AML) during winter. In this PhD project, high-resolution Large-Eddy Simulations (LES) will be generated to accompany these observational datasets. The objective is i) to supplement the measurements with virtual three-dimensional fields, and ii) to use the LES as a laboratory to study interactions between turbulence, clouds, radiation, the surface and larger–scale dynamics. The simulations will be performed for each suitable day during the MOSAiC drift, yielding a library of over a 100 cases. The Lagrangian setup of these simulations follows air masses as they move towards the ship. Model results will be evaluated against independent MOSAiC measurements. Statistical interpretation of big datasets will be performed to identify controls on the evolution of the AML as embedded in warm and moist air intrusions. Hypotheses will be tested concerning the formation and maintenance of humidity layers above the thermal inversion of the AML, focusing on the role of surface heterogeneity. Obtained results will be published in high-end peer-reviewed scientific journals and presented at international conferences.

Specific requirements for this project:

• A strong interest in high-resolution numerical simulation of geophysical flows, boundary-layer meteorology, Arctic clouds and climate, and conceptual modeling
• Interest in confronting simulations with state-of-the-art MOSAiC measurements, in close collaboration with our project partners at TROPOS in Leipzig
• An investigative mindset, highly motivated to gain new scientific insights into an ongoing major shift in Earth's climate (Arctic Amplification)

According to the guidelines in the official (job posting), please send your application (as a single pdf file) and questions regarding this project to Prof. Dr. R. Neggers (neggers@meteo.uni-koeln.de). The deadline for applications is 15 February 2020