C3S Atlas Precipitation Projections

The Copernicus Interactive Climate Atlas is developed by the Copernicus Climate Change Service (C3S), operated by ECMWF on behalf of the European Commission. It provides an interactive web application and a gridded dataset for exploring observed and projected changes in a wide range of climate variables across Europe and the globe.

Dataset: Multi-origin C3S Atlas¶

Full name: Gridded dataset underpinning the Copernicus Interactive Climate Atlas
CDS identifier: multi-origin-c3s-atlas
Coverage: Global/European, multiple time periods
Source: cds.climate.copernicus.eu/datasets/multi-origin-c3s-atlas

The dataset bundles pre-processed climate indices derived from multiple sources (observations and model ensembles) and is the underlying data store for the C3S Interactive Climate Atlas web application. In this book, the EURO-CORDEX subset is used.

Data citation: Copernicus Climate Change Service, Climate Data Store (2024)

EURO-CORDEX ensemble¶

This book uses the EURO-CORDEX component of the C3S Atlas dataset (origin: cordex_eur_11, domain: euro_cordex), which is a coordinated ensemble of regional climate model (RCM) simulations dynamically downscaling ERA-Interim-driven global climate models over Europe.

Each ensemble member is identified by a unique combination of global climate model (GCM) driver and regional climate model (RCM). Downloading all available members for a given scenario and variable yields a multi-model ensemble that captures the range of plausible future climates.

Variable used in this book¶

Variable: Monthly maximum of daily precipitation (monthly_maximum_1_day_precipitation, also referred to as Rx1day)

Rx1day is the highest single-day precipitation total observed within a calendar month. Annual maxima of this quantity are the standard input for extreme-value analysis (GEV fitting and return-period estimation). Using monthly maxima rather than raw daily values reduces storage requirements while preserving the statistical information needed for block-maxima approaches.

RCP scenarios¶

Three Representative Concentration Pathways (RCPs) are used, representing a range of greenhouse-gas emission trajectories:

Using all three scenarios is essential for characterising scenario uncertainty — the spread between RCPs grows substantially in the second half of the 21st century.

How the data are used in this book¶

The downloaded NetCDF files are processed by the How-To Guide on Projections of Precipitation, which:

1. Clips the global/European grid to the bounding box of the target NUTS2 region.

2. Extracts the monthly Rx1day values for every grid point inside the region boundary.

3. Computes annual maxima (block maxima) per model–grid-point combination.

4. Saves the results to CSV files used by the tutorials.