Rupert Klein (Freie Universität Berlin): How Mathematics Helps Structuring Climate Discussions

Coffee and cookies at 16:45 in room 1404.

Abstract:

Mathematics in climate research is often thought to be mainly a provider of techniques for solving the continuum mechanical equations for flows of the atmosphere and oceans, for the motion and evolution of Earth’s ice masses, and the like. Three examples will elucidate that there is a much wider range of opportunities.

Climate modellers often employ reduced forms of “the continuum mechanical equations” to efficiently address their research questions of interest. The first example discusses how mathematical analysis can provide systematic guidelines for the regime of applicability of such reduced model equations.

Physics-based computational models are well established for weather forecasting,which aims at deterministic prediction, and for climate scenario simulations, which aim at generating weather statics utilizing the hypothesis of ergodicity. Intermediate time scale predictions for, e.g., the occurance of El Niño events, fit into neither of these categories. Accordingly, physics-based models have difficulties reaching the predictive horizon desirable for agricultural planning and the like.

Modern climate research has joined forces with economy and the social sciences to generate a scientific basis for informed political decisions in the face of global climate change. One major type of problems hampering progress of the related interdisciplinary research consists of often subtle language barriers. The third example describes how mathematical formalization of the notion of “vulnerability” has helped structuring related interdisciplinary research efforts.

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Rupert Klein received his doctorate in 1988 in mechanical engineering at RWTH Aachen University and then spent two years as a postdoc with Andrew Majda at the Program of Applied and Computational Mathematics of Princeton University. After his habilitation back in Aachen in 1995 he was a professor for Safety Technology at Bergische Universität Wuppertal before accepting a chair in Scientific Computing at Freie Universität Berlin in 1997, with a focus on geophysical fluid dynamics. From 1997 to 2007 he headed the Data & Computation department at the Potsdam-Institute for Climate Impact Research, where he also served as the deputy director in 2006/07.

In his research he develops and employs techniques of asymptotic analysis and numerics for multi-scale dynamics to improve our understanding of a broad range of application problems. Besides the geophysical fluid dynamics of weather and climate, these include, e.g., the reactive gas dynamics of pressure-gain combustion for gas turbines and electronic structure problems associated with solar energy conversion. His department’s research at the Potsdam Institute led to the mathematical formalization of otherwise rather ambiguous natural language concepts such as “vulnerability” or “resilience”, which are widely used in climate impact studies.

In 2003 he received the German Leibniz award and in 2005 became a member of the Berlin-Brandenburgische Akademie der Wissenschaften. Other awards Klein received include a 2x3-year fellowship of the European Centre for Medium Range Weather Forecasts (ECMWF), Reading, UK (2014, 2017).