Regional climate downscaling over Europe: perspectives from the EURO-CORDEX community

Abstract

The European CORDEX (EURO-CORDEX) initiative is a large voluntary effort that seeks to advance regional climate and Earth system science in Europe. As part of the World Climate Research Programme (WCRP)-Coordinated Regional Downscaling Experiment (CORDEX), it shares the broader goals of providing a model evaluation and climate projection framework and improving communication with both the General Circulation Model (GCM) and climate data user communities. EURO-CORDEX oversees the design and coordination of ongoing ensembles of regional climate projections of unprecedented size and resolution (0.11 • EUR-11 and 0.44 • EUR-44 domains). Additionally, the inclusion of empiricalstatistical downscaling allows investigation of much larger multi-model ensembles. These complementary approaches provide a foundation for scientific studies within the climate research community and others. The value of the EURO-CORDEX ensemble is shown via numerous peer-reviewed studies and its use in the development of climate services. Evaluations of the EUR-44 and EUR-11 ensembles also show the benefits of higher resolution. However, significant challenges remain. To further advance scientific understanding, two flagship pilot studies (FPS) were initiated. The first investigates local-regional phenomena at convection-permitting scales over central Europe and the Mediterranean in collaboration with the Med-CORDEX community. The second investigates the impacts of land cover changes on European climate across spatial and temporal scales. Over the coming years, the EURO-CORDEX community looks forward to closer collaboration with other communities, new advances, supporting international initiatives such as the IPCC reports, and continuing to provide the basis for research on regional climate impacts and adaptation in Europe.

Is interactive air sea coupling relevant for simulating the future climate of Europe?

“…Dirmeyer et al 2014;Rahman et al 2015;Knist et al 2017) which in Europe are mainly subject to land use management (Davin et al 2020) rather than the influence of climate as this is the case in less dense populated regions (Wu et al 2016). Thus, the present study can be considered an extension to the challenge "Impacts of coupled processes and land-atmosphere feedbacks in a regional context" (Jacob et al 2020) as coupled atmosphere-ocean a feedbacks are focused. Thus, the aim of the this study is to provide a coupled atmosphere-ocean RCM to downscale a multi global model-multi scenario ensemble to asses the climate change at the end of the twenty-first century.…”

“…Past trends in dynamical downscaling made use of declining computational costs and resulted in increasing model resolution and longer integration time scales. In the future these trends will lead to more realistic convection permitting models and will allow ensemble simulations at the centennial scale (Lake et al 2017;Giorgi 2019;Jacob et al 2020). With longer time scales to be addressed the greater uncertainty is associated with the slower components of the climate system such as the ocean which comprises a large part of the Euro-CORDEX domain.…”

“…This gives impetus to the development of coupled atmosphere ocean-models which replace the prescribed ocean surface (mainly sea surface temperatures (SST) and sea ice) by high resolution ocean General Circulation Models (GCMs). Jacob et al (2020) emphasized the impact of coupling processes among the current challenges for regional climate research within Euro-CORDEX. The authors focused primarily on the importance of atmosphere-land coupling effects (e.g.…”

“…The future trend of regional climate modelling will demand for higher horizontal resolution up to convection permitting scales of only a few kilometers (Giorgi 2019;Jacob et al 2020). At these resolution interactive air sea coupling can be expected to be more beneficial.…”

“…Today, such biophysical effects are mostly passively taken into account through scenarios for future land use (e.g. Jacob et al 2020) assuming that the land surface is mainly managed rather than subject to climate change. However, climate-vegetation interactions have been shown to be important in less dense populated areas (e.g.…”