Group seminar on 24. November, 14:15 CET
Bridging the gap between theory and reality in weather and climate extremes
Weather and climate extremes pose a significant threat to societies and economies around the world. Their compound nature can also exacerbate losses when compared to univariate extremes. In recent years, new developments deriving from the combination of extreme value theory (EVT) with dynamical systems theory (DST) opened new horizons with respect to applied research on weather and climate extremes and climate science in general. However, links between these new techniques, which describe the evolution of atmospheric variables in the phase-space, and physical extremes are not always obvious as one may think.
In this presentation, I will describe the DST method for both univariate and compound Poincaré recurrences in the phase-space, along with four case studies that try to bridge the gap between dynamical metrics and physical extremes in different regions around the globe.
In the first case study, winter wet-windy and cold-wet compound extremes are quantified in Europe and Eastern North America within the observational period 1979-2018. The second work uses the same time-period, however it quantifies summer warm-dry and winter cold-wet compound extremes over the Mediterranean. Finally, the last two studies remain purely theoretical, but make use of reanalysis and large CMIP6 multi-model ensembles. One assesses summer weather persistence over the northern hemisphere mid-latitudes and the other quantifies the dynamical coupling between temperature and relative humidity across the northern and southern hemisphere mid-latitudes. Both studies investigate observational and future climate periods.
Conclusions about the case studies and future challenges/opportunities within the field of DST applications to weather and climate extremes will end the presentation.