Feb 15 2021
According to a new study, future climate scenarios for the Eastern Alps indicate less intense mean daily precipitation and more intense, localized extreme events.
Image Credit: CMCC Foundation.
Titled 'Evaluation and Expected Changes of Summer Precipitation at Convection Permitting Scale with COSMO-CLM over Alpine Space,' the study has been published in the Atmosphere journal by the CMCC Foundation.
The study was performed in the context of the European project H2020 EUCP (European Climate Prediction system) and adds to the research of the international scientific community in developing climate models with the potential to support decision-makers in a proper evaluation of extreme events and their evolution based on climate change.
The ultimate aim is to limit its negative effects on economies and societies.
The current climate change adaptation plans and measures across the globe are based on future scenarios presented to decision makers by the scientific community. At present, these scenarios offer an ideal representation of extreme events on a daily scale. However, they still exhibit only limited predictive capabilities at a sub-daily time scale.
In the case of certain sectors, for example, infrastructure, there is inadequate information that can be used to develop sufficient climate change adaptation policies: extremely intense and quick rainfall, concentrated in small areas and within a few hours, can have very high impacts on infrastructure, which results in the overflow of water bodies and flooding, undermining systems, and disclosing the inability of sewerage to manage huge water flows.
Certain extreme events can last for a few hours and have an impact on very small areas (in the order of a few kilometers). The need to gain insights about such phenomena is much higher in certain particular geographical contexts, like the Alpine area, where extreme rainfall events—typically occurring in the summer season—can have perilous impacts.
In recent decades there has been an ongoing debate among climatologists about the added value of very high-resolution climate simulations, representing the next generation of the regional climate-models.
Paola Mercogliano, Director, Regional Models and geo-Hydrological Impacts Division, CMCC Foundation
“These climate simulations, which are run with regional models at a very high spatial and temporal resolution, have a high computational cost and require significant investments in terms of research time. Given the high costs, the scientific community is questioning whether this is the right way to go to better support climate change adaptation policies,” added Mercogliano.
Our study demonstrates the added value of this direction and confirms that it is worth investing in it, especially in areas with complex orography or where uncertainty is still wide, such as the Alps. With these new generation models, we can not only observe what happens at very high resolutions in terms of mean daily precipitation, but we can also make statistical analyses on a sub-daily basis, looking at different hours of the same day.
Paola Mercogliano, Director, Regional Models and geo-Hydrological Impacts Division, CMCC Foundation
“These models will also be able to provide information on the effects of climate change on hourly precipitation: results that would have been unthinkable just two or three years ago,” she stated
The research offers an improved representation of precipitation intensity and frequency in extremely high resolution simulations ('convection permitting') compared to lower resolution simulations, specifically at a sub-daily scale.
In agreement with existing literature, our preliminary results for the Alpine area in the summer season show a decrease in mean daily precipitation, especially at high altitudes, and localised intensifications of extreme events along the Eastern Alps. It will rain less frequently but more intensely, both on a daily and hourly time scale.
Marianna Adinolfi, Study Lead Author and Researcher, CMCC Foundation
“Given the increased intensity of these events, it is clear that understanding the distribution of rainfall at hourly scale can bring great added value in our support for decision-makers,” added Adinolfi.
The CMCC Foundation develops and applies futuristic climate models in various international projects and contexts.
Certain examples are the investigation of urban heatwaves and the evolution of rainfall extremes in support of adaptation policies on an urban scale—all contexts that will benefit from simulations on hourly scales.
The CMCC Foundation developed products like the Climate Scenarios for Italy to support adaptation policies, which enables visualizing the predicted climate in maps until the end of the century with the help of high resolution climate models, and climate services like Dataclime, which offers tailored climate analysis on multiple spatial and temporal scales.
This research was performed within the framework of the Horizon 2020 research project EUCP, in which the CMCC Foundation participates.
The goal of the project is to support the world of research to develop high quality climate data and predictions on a European scale to be offered to stakeholders, policymakers and planners to mitigate the challenges and opportunities that climate change brings.
Journal Reference:
Adinolfi, M., et al. (2020) Evaluation and Expected Changes of Summer Precipitation at Convection Permitting Scale with COSMO-CLM over Alpine Space. Atmosphere. doi.org/10.3390/atmos12010054.