B0243
Title: Spatial modeling and future projection of extreme precipitation extents
Authors: Peng Zhong - University of New South Wales (Australia) [presenting]
Manuela Brunner - ETH Zurich (Switzerland)
Thomas Opitz - BioSP-INRAE (France)
Raphael Huser - King Abdullah University of Science and Technology (Saudi Arabia)
Abstract: Extreme precipitation events with large spatial extents may have more severe impacts than localized events as they can lead to widespread flooding. It is debated how climate change may affect the spatial extent of precipitation extremes, whose investigation often directly relies on simulations from climate models. A different strategy is used to investigate how future changes in spatial extents of precipitation extremes differ across climate zones and seasons in two river basins (Danube and Mississippi). Observed precipitation extremes are relied on while exploiting a physics-based mean temperature covariate, which enables to projection of future precipitation extents. The covariate is included in newly developed time-varying r-Pareto processes using a suitably chosen spatial aggregation functional r. This model captures temporal non-stationarity in the spatial dependence structure of precipitation extremes by linking it to the temperature covariate, which is derived from observations for model calibration and from bias-corrected climate simulations (CMIP6) for projections. For both river basins, the results show a negative correlation between the spatial extent and the temperature covariate for most of the rain season and an increasing trend in the margins, indicating a decrease in spatial precipitation extent in a warming climate during rain seasons as precipitation intensity increases locally.
