15 June 2020 | Hans Hersbach, Bill Bell, Paul Berrisford, Shoji Hirahara, András Horányi, Joaquín Muñoz-Sabater, Julien Nicolas, Carole Peubey, Raluca Radu, Dinand Schepers, Adrian Simmons, Cornel Soci, Saleh Abdalla, Xavier Abellan, Gianpaolo Balsamo, Peter Bechtold, Gionata Biavati, Jean Bidlot, Massimo Bonavita, Giovanna De Chiara, Per Dahlgren, Dick Dee, Michail Diamantakis, Rossana Dragani, Johannes Flemming, Richard Forbes, Manuel Fuentes, Alan Geer, Leo Haimberger, Sean Healy, Robin J. Hogan, Elias Hólm, Marta Janisková, Sarah Keeley, Patrick Laloyaux, Philippe Lopez, Cristina Lupu, Gabor Radnoti, Patricia de Rosnay, Iryna Rozum, Freja Vamborg, Sébastien Villaume, Jean-Noël Thépaut
The paper introduces the ERA5 global reanalysis, which is being produced by the European Centre for Medium-Range Weather Forecasts (ECMWF) as part of the Copernicus Climate Change Service (C3S). ERA5, based on the Integrated Forecasting System (IFS) Cy41r2, offers significant improvements over its predecessor, ERA-Interim, with enhanced horizontal resolution (31 km vs. 80 km), hourly output, and uncertainty estimates from an ensemble system. The paper highlights the advancements in model physics, data assimilation, and observation handling, including improvements in radiation schemes, convection parametrizations, land surface processes, and ocean wave dynamics. ERA5 also introduces innovations such as a hybrid incremental 4D-Var system, advanced land data assimilation, and improved ozone chemistry. The paper provides a detailed overview of the configuration of ERA5, including the assimilation system, ensemble component, and observational data handling. It also discusses the benefits of these improvements, such as enhanced skill in re-forecasts, improved fit with radiosonde and PILOT data, and better representation of ocean wave heights. The paper concludes by emphasizing the availability of ERA5 data through the C3S Climate Data Store and the timely updates provided to users.The paper introduces the ERA5 global reanalysis, which is being produced by the European Centre for Medium-Range Weather Forecasts (ECMWF) as part of the Copernicus Climate Change Service (C3S). ERA5, based on the Integrated Forecasting System (IFS) Cy41r2, offers significant improvements over its predecessor, ERA-Interim, with enhanced horizontal resolution (31 km vs. 80 km), hourly output, and uncertainty estimates from an ensemble system. The paper highlights the advancements in model physics, data assimilation, and observation handling, including improvements in radiation schemes, convection parametrizations, land surface processes, and ocean wave dynamics. ERA5 also introduces innovations such as a hybrid incremental 4D-Var system, advanced land data assimilation, and improved ozone chemistry. The paper provides a detailed overview of the configuration of ERA5, including the assimilation system, ensemble component, and observational data handling. It also discusses the benefits of these improvements, such as enhanced skill in re-forecasts, improved fit with radiosonde and PILOT data, and better representation of ocean wave heights. The paper concludes by emphasizing the availability of ERA5 data through the C3S Climate Data Store and the timely updates provided to users.