The fifth OpenIFS user workshop was held from 17 to 21 June 2019 at the Department of Meteorology, University of Reading, on ‘The Impact of Moist Processes on Weather Forecasts’. The meeting attracted 60 scientists from institutes in Europe and further afield. It was organised around case-study-based exercises using OpenIFS run on ECMWF’s high-performance computing facility.
The OpenIFS activity at ECMWF (https://confluence.ecmwf.int/oifs/) provides a supported version of the operational Integrated Forecasting System (IFS) model for research and education. User workshops are an opportunity for scientists to interact, present their work with OpenIFS and learn more about ECMWF. Each meeting focuses on an active research area at ECMWF with invited and contributing presenters.
Training and research
In response to feedback from previous workshops, this year the first day of the workshop was dedicated to lectures and exercises designed to teach participants more about the model itself. Several ECMWF scientists gave lectures on the spectral method, the semi-Lagrangian dynamical core, the radiation scheme and lake modelling parametrization. The latter two talks highlighted new aspects of the new release of OpenIFS based on IFS Cycle 43r3. The practical exercises on that day were designed for participants who were new to OpenIFS or had very limited user experience.
The scientific programme began on 18 June and was opened by Paul Williams from the Department of Meteorology, University of Reading, and Andy Brown, Director of Research at ECMWF, who gave overviews of research under way at both institutes. Each morning featured a combination of invited and contributed presentations. The high-quality talks by nine invited speakers and ten contributing speakers and the 14 poster presentations provided examples of the diverse activities under way with the OpenIFS models. The launch event for the new ‘OpenIFS@Home’ facility also took place at the workshop. David Wallom, of the Oxford e-Science Centre, described how OpenIFS can now be run on volunteers’ personal computers to generate ensembles with many thousands of members for new research possibilities. As a demonstration, during the workshop a 2,000-member ensemble was distributed to public volunteers, and preliminary results were shown on the final day of the workshop.
The afternoons were devoted to running OpenIFS using a forecast case study taken from the NAWDEX field campaign (the North Atlantic Waveguide and Downstream impact Experiment, https://www.pa.op.dlr.de/nawdex/index.html). The campaign followed the development of tropical storm Karl as it transitioned to an extratropical system. To explore the role of physical processes, the model was modified to allow the definition of a three-dimensional ‘box’ in which the impact of radiation, cloud and convection processes could be increased or decreased. Participants worked in teams with guidance from experienced researchers and devised experiments to understand the role of these processes in the model forecasts of the resulting extreme precipitation over Scotland and Norway.
The workshop made the user community aware of many improvements and new features in the soon-to-be-released OpenIFS 43r3 version. The exercises provided an opportunity for training and first-hand experience with the new model. Beyond these developments within ECMWF, the workshop showcased external developments, for instance the use of OpenIFS as part of the forthcoming EC‑Earth4 community Earth system model; coupling OpenIFS to 3D ocean models such as FOCI-OpenIFS; and the generation of initial conditions using the AutoSubmit software tool. In oral and poster presentations, the role of diabatic processes in both mid-latitude and tropical forecasting errors was explored. The discussions continued during tea and lunch breaks, and the user community presented examples of how OpenIFS is applied as a research and teaching tool in idealised experiments and in forecasting case studies. Finally, it was shown that OpenIFS can run on a wide variety of platforms, including large numbers of volunteer PCs and even on four Raspberry Pi microcomputers! Early feedback suggests that participants appreciated the “good set of speakers at the workshop” and the “opportunity for interaction between ECMWF scientists and OpenIFS users”.
The workshop was organised jointly by the Department of Meteorology at the University of Reading and ECMWF. It would not have been possible without financial support from the EU ESiWACE programme, the European Geophysical Union, the Department of Meteorology at the University of Reading, the University of Reading’s Research Endowment Trust Fund, and ECMWF. The organisers would like to thank all those who helped.