Arbeitsgruppe Klimadynamik und Statistik

ClimXtreme investigates how climate change alters extreme weather events. We aim at creating a knowledge base that users, decision-makers and society can use to plan their response to changing impacts.

Module B is concerned with the statistical description of extreme events, their probability of occurrence and their development over time.

Our focus is on the detection and attribution of changes in weather extremes, on Bayesian extreme event attribution and on the compact description of spatio-temporal extremes.

Members

Petra Friederichs, Sebastian Buschow, Svenja Szemkus, Magdalena Kracheletz, Pascal Meurer

Friederichs et al. (2024): Ergiebige Dauerniederschläge und Hochwasser in Süddeutschland im Mai und Juni 2024. Bericht des Forschungsnetzwerkes ClimXtreme, doi: 10.17169/refubium-44009

Buschow, S., P. Friederichs and A. Hense (2024): Reconciling risk-based and storyline attribution with Bayes theorem. Advances in Statistical Climatology, Meteorology and Oceanography (submitted, arXiv:2407.10776)

Szemkus, S., and P. Friederichs (2024): Spatial patterns and indices for heatwave and droughts over Europe using a decomposition of extremal dependency. Adv. Stat. Clim. Meteorol. Oceanogr. 10, 29-49, doi: 10.5194/ascmo-10-29-2024.

Meuer, P., S. Buschow, S. Szemkus and P. Friederichs (2024): Non-stationary attribution of heatwaves over Europe. (in preparation)

DETECT aims at improving our understanding of regional climate change beyond greenhouse gas (GHG) forcing. We focus on disentangling the role that changes in land use and water management as drivers of climate change can play via modifying the water cycle.

Aim of D04 is to investigate to what extent this improves the representation of extreme events. Our focus here is on meteorological droughts and heat waves. We compare the characteristics of extremes in the integrated modeling system with observations and reanalyses. Additionally, the impacts of different scenarios on simulation results will be addressed to attribute the extreme behavior to different forcings. Using the comprehensive representation of the water and energy cycle in the modeling system, we are especially interested in human influence, specifically changes in human land and water use.

Members

Till Fohrmann, Petra Friederichs, Oliver Heuser

"Coming Decade" aims to significantly improve climate predictions for Europe for decadal time scales and to develop climate services to support decision making for the coming years.
We will update the decadal climate prediction system by using ICON-Seamless and use the given opportunity of a higher resolution sub-area within the global grid of ICON to get a higher resolution for Europe. We will also implement a model-consistent initialization in atmosphere and ocean, which will technically raise the forecast system to a new level compared to other international forecast systems.

We contribute to the development of user-specific products for sectoral applications with statistical adjustment for reliable probabilistic predictions, and to the verification of extremes and multivariable indices.

Members

Philipp Ertz, Petra Friederichs

For generating monthly level-2 gravity fields from GRACE and GRACE-FO satellinges, it is mandatory to remove sub-monthly non-tidal atmospheric and ocean mass variability during level-1 processing.

The IP3 group of Uni Bonn focus on improving our understanding of atmospheric mass redistribution and the errors in atmospheric simulations. We investigate sub-monthly variability in the coupled atmospheric-terrestrial hydrological cycle, and we assess the potential of hydrology model simulations to improve the de-aliasing. This project has al-ready generated a consistent global data set of atmospheric-hydrological mass variation with improved spatio-temporal resolution over Europe, and it will continue to serve the RU through validation experiments. Finally, with a view on the current ~20 year data record that NGGMs will be able to extend to climate timescales, we suggest to shift the focus on the possibility of detecting hydrometeorological extremes and their statistics in a warming climate.

Members

Ziyu Liu, Christian Mielke, Anne Springer, Petra Friederichs, Jürgen Kusche

Kracheletz, M., Z. Liu, A. Springer, J. Kusche, and P. Friederichs (2024): Water mass variations during severe flooding in Western Europe July 2021 and their influence on gravity field measurements by satellite missions. J. Geophys. Res. (submitted)

Springer, A., C. Mielke, Z. Liu, S. Dixit, P. Friederichs, and J. Kusche (2024): A regionally refined and mass-consistent atmospheric and hydrological de-aliasing product for GRACE, GRACE-FO and future gravity missions. Journal of Geophysical Research - Solid Earth, doi: 10.1029/2023JB027883

The project HIRES-APP (2024–2027) of the Hans-Ertel-Centre for Weather Research (HErZ) is a joint research group of the Universities of Bonn, Cologne and Tübingen. Our research aims at providing basic research for the German Meteorological Service (Deutscher Wetterdienst, DWD) and to initiate and support new developments within DWD. We contribute primarily to the HErZ competence areas Climate monitoring and Earth system forecasting with contributions to Data assimilation and predictability as well as Optimal use of weather and climate information.

Members

Leonie Esthers, Yann Büchau, Petra Friederichs