A team of German and Swiss researchers at Empa has reached a milestone in weather and climate research: since the beginning of February, the famous ICON climate and weather model has been available to all interested parties under an open source license. This initiative aims to make science and the scientific services that go with it more transparent. At the same time, it fosters new scientific advances in a field that can be of particular benefit to society at a time of climate change.
ICON (ICOsahedral Non-hydrostatic modelling framework) is a numerical weather model that uses three-dimensional computer simulation to calculate changes in the atmosphere over the coming hours and days. Such weather models are mainly used by national meteorological services such as the Swiss Federal Office of Meteorology and Climatology (MeteoSwiss). The research institutions behind ICON and its current developers are the Center for Climate Systems Modeling (C2SM, itself made up of the Federal Office of Meteorology and Climatology MeteoSwiss, ETH Zurich, Empa and WSL), the German Center for Climate Calculations (DKRZ), the German Weather Service (DWD), the Karlsruhe Institute of Technology (KIT) and the Max Planck Institute for Meteorology (MPI-M).
ICON shows just how beneficial collaboration between research and national meteorological services can be: close cooperation enables highly accurate weather forecasts and climate projections, which benefit not only the scientific community but also the general public. The publication of the code is an important step towards strengthening confidence in science and research institutions. Oliver Fuhrer, Head of the Numerical Forecasting Department at MeteoSwiss, emphasizes: “The open availability of the ICON model marks a decisive moment in meteorological research. The ICON model is currently in the test phase at MeteoSwiss, with the aim of using it for daily weather forecasts later this year”.
ICON was initially developed jointly by the DWD and MPI-M as an atmospheric and meteorological forecasting model, and is now used in Germany and Switzerland for operational weather forecasting. With regard to climate research, MPI-M has developed models adapted to other components of the Earth system, enabling ICON to be used as a coupled climate and Earth system model. In addition to the model component for ocean circulation, others exist for marine biogeochemistry as well as for terrestrial biosphere and hydrological processes.
The specially developed Community Interface (ComIn), for example, enables scientists to extend the ICON model with their own add-on modules without having to modify the complex model code. This not only promotes flexibility in research, but also frees up the power of innovation within the scientific community.
KIT has developed a model component – ICON-ART – which enables the prediction of aerosols and atmospheric chemistry and their interaction with the physical state of the atmosphere. Aerosols and the chemical composition of the atmosphere determine air quality and influence solar radiation, clouds and precipitation. Empa also participated in the development of ICON-ART, developing a module for the efficient integration of emission data and implementing a detailed chemical reaction scheme, which is important for air quality simulations. The YAC software component needed to couple the submodels was developed jointly by DKRZ and MPI-M and released as open source from the outset.
All sub-models are included in the open source version, enabling ICON to be used in a wide range of resolutions and configurations for a multitude of applications – from global and regional weather forecasts and climate projections to very high-resolution “digital twins” of the Earth system.
The publication of the ICON model’s source code under an open source license is a decisive step towards open, transparent, high-quality and collaborative science. Researchers from all over the world will have the opportunity to draw on one of the world’s leading weather forecasting and climate simulation models, and to work together on pioneering projects. Commercial use is also possible under license. This publication comes at a time when the research landscape is changing, encouraging greater collaboration and knowledge exchange.
The open source version facilitates the integration of ICON into international research collaborations and strengthens Europe’s position in the field of climate and weather research. It also enables more effective collaboration with supercomputer manufacturers, who can test and improve the performance of their hardware using weather and climate models.
Scientific benefits and broader applications
“The open source license will simplify the exchange with our scientific partners and could support the creation of new innovative start-ups in the environmental sector,” says Dominik Brunner, head of the Atmospheric Modelling and Remote Sensing group in Empa’s Air Pollution / Environmental Technology laboratory. According to Brunner, ICON-ART, combined with ground measurements and satellite data, also enables even more reliable detection and quantification of sources of greenhouse gases and air pollutants.
Brunner’s team has just published an impressive example on the EGUsphere expert platform. The researchers used ICON-ART to estimate methane emissions across Europe and compared them with the quantities officially reported by individual countries. According to the Empa researcher, there is a very good match for many countries, some even having lower emissions than reported – while others have significantly higher emissions. The study will soon be published in the journal Atmospheric Chemistry and Physics.
Source : Press Release
