D3.2 Report on the dynamical downscaling of climate and atmospheric impacts 1st version

This report, titled “D3.2 -- Report on the dynamical downscaling of climate and atmospheric impacts 1st version”, presents the downscaling approaches and methods developed and employed for large-scale climatological and meteorological data in the PLOTO project Task 3.3. The large-scale data originates from Regional Climate Model (RCM) predictions for the future climate scenarios and from Numerical Weather Prediction (NWP) model data for short term forecasts. The selection of the climatological data from the EURO-CORDEX database has been reported in the deliverable report D3.1. The short-term data to be downscaled is obtained from the ICON-EU NWP system. Downscaling of the future climate projections addresses the STO 2 of PLOTO “Reliable quantification of climatic, hydrological and atmospheric stressors”, and the short-term downscaled forecasting addresses the STO 3 “Development of a forecasting module to provide high-resolution tailored weather and precipitation forecasts”.
We describe also the PLOTO use cases and their relevant weather vulnerabilities and hazards as a basis for selecting the data to be downscaled and designing the sets of resulting downscaled data.
As the resolutions of the RCM and NWP models are relatively low, they cannot capture any effects of local small-scale features of specific sites of interest like fine-grained terrain shape, buildings and trees. Therefore, the data must be downscaled to local scale and high resolution so that the effects of the local features are properly captured.
We apply two downscaling approaches. For wind data, we apply an approach based on precomputed very high resolution Large-Eddy Simulation (LES) data and data fusion. For other meteorological variables of interest: temperature, relative humidity, cloud cover and precipitation we apply high-resolution meso-scale modelling. We also present two examples of downscaling. All the downscaling tasks for all use cases, their specific features and the results will be presented in the report D3.3.
The downscaled RCM data for future-climate scenarios will be used as input to Task 3.6 for the assessment of the site-specific climate risk parameters and stressor indicators. In WP4, downscaled climatic projections will be used for infrastructure resilience assessment. The short-term downscaled forecasting systems developed here will be used in Task 3.4 to obtain tailored forecasts for the use case sites for the needs of dynamical data assimilation in Task 3.5 and in WP6 to support IWAT, Decision support system and Enhanced Visualization Interface.