PhD in Climate Science | Ελβετία

PhD in Climate Science – Understanding and quantifying low probability-high impact extremes

The overall objective is to improve our understanding and the quantification of the occurrence of low probability-high impact extremes in a changing climate. The project combines novel climate model experiments with advanced methods of extreme value analysis in order to advance research on temperature and precipitation extremes beyond the traditionally studied moderate definitions. (A) The objective of the first PhD project is to improve our understanding of the physical mechanisms driving very rare extremes with a focus on atmospheric dynamics, surface energy budget, and anomalous land surface conditions. A novel approach is introduced and tested to efficiently generate very rare extremes using the NCAR CESM global climate model. Very long control simulations and large ensembles are used as a testbed to identify physical constraints leading to potential upper bounds in extremes and how they are affected by climate change. (B) The objective of the second PhD project is to identify strengths and limitations of stationary and non-stationary extreme value analysis in estimating return levels of very rare events and to quantify temporal clustering and compound aspects of very rare extremes. Limitations of stationarity and added value of non-stationary extreme value analysis using process-based covariates will be analysed using very long climate model simulations as testbeds. Finally, the project will further explore characteristics of low-probability high-impact extremes that arise through temporal clustering and compound aspects of multivariate extremes.