Meteorological Society of Japan Publication Award for HD(CP)2 Added Value Paper

A group of scientists at the Max Planck Institute for Meteorology (MPI-M) were recognized for their co-authorship of the paper “The added value of large-eddy and storm-resolving models for simulating clouds and precipitation”, which was awarded the 2020 Meteorological Society of Japan Publication Award. The paper demonstrates the ability of models run at hecto- and kilo-meter scales, to surmount long standing obstacles hindering more accurate climate predictions. Models run at kilometer scales are shown to improve predictions of precipitation, particularly in the tropics, including extremes. Simulations at hector-meter scales are shown not to be especially crucial for precipitation, but important for cloud prediction, particularly shallow maritime clouds. The paper thereby provides the scientific foundation for efforts to create a new class of storm-resolving (or kilometer scale) climate models as envisioned for major new European initiatives such as ‘NextGEMS’ and ‘Destination Earth’.

The “Added-value” publication was the capstone study of the BMBF-funded HD(CP)2 project, which was led by MPI-M. Fifty-seven scientists, drawn from institutes across Germany, were involved as authors. Led by Bjorn Stevens of the MPI-M department “The Atmosphere in the Earth System”, the paper featured contributions from more than a dozen MPI-M scientists, with Rieke Heinze, Wiebke Schubotz and Julia Windmiller of the MPI-M joining Claudia Acquistapace (University of Cologne), Akio Hansen (Universität Hamburg), Carolin Klinger (Ludwig-Maximilians-Universität Munich), and Daniel Klocke (DWD – German Meteorological Service) as co-leads.

“The nicest form of recognition is that given for one’s specific scientific accomplishments. Receiving this award from such an esteemed society, one which has made pioneering contributions to numerical modeling of weather and climate, is especially gratifying and helps validate the enormous efforts of the entire HD(CP)2 community in exploring the potential of hecto- and kilo-meter scale models for climate applications”, remarked Prof. Stevens upon learning of the award.

Abstract of the publication
More than one hundred days were simulated over very large domains with fine (0.156 km to 2.5 km) grid spacing for realistic conditions to test the hypothesis that storm (kilometer) and large-eddy (hectometer) resolving simulations would provide an improved representation of clouds and precipitation in atmospheric simulations. At scales that resolve convective storms (storm-resolving for short), the vertical velocity variance becomes resolved and a better physical basis is achieved for representing clouds and precipitation. Similarly, to past studies we found an improved representation of precipitation at kilometer scales, as compared to models with parameterized convection. The main precipitation features (location, diurnal cycle and spatial propagation) are well captured already at kilometer scales, and refining resolution to hectometer scales does not substantially change the simulations in these respects. It does, however, lead to a reduction in the precipitation on the time-scales considered – most notably over the ocean in the tropics. Changes in the distribution of precipitation, with less frequent extremes are also found in simulations incorporating hectometer scales. Hectometer scales appear to be more important for the representation of clouds, and make it possible to capture many important aspects of the cloud field, from the vertical distribution of cloud cover, to the distribution of cloud sizes, and to the diel (daily) cycle. Qualitative improvements, particularly in the ability to differentiate cumulus from stratiform clouds, are seen when one reduces the grid spacing from kilometer to hectometer scales. At the hectometer scale new challenges arise, but the similarity of observed and simulated scales, and the more direct connection between the circulation and the unconstrained degrees of freedom make these challenges less daunting. This quality, combined with already improved simulation as compared to more parameterized models, underpins our conviction that the use and further development of storm-resolving models offers exciting opportunities for advancing understanding of climate and climate change.

Original publication

Stevens, B., Acquistapace, C., Hansen, A., Heinze, R., Klinger, C., Klocke, D., Schubotz, W., Windmiller, J., Adamidis, P., Arka, I., Barlakas, V., Biercamp, J., Brueck, M., Brune, S., Buehler, S., Burkhardt, U., Cioni, G., Costa-Surós, M., Crewell, S., Crueger, T., Deneke, H., Friederichs, P., Henken, C., Hohenegger, C., Jacob, M., Jakub, F., Kalthoff, N., Köhler, M., van Laar, T., Li, P., Lohnert, U., Macke, A., Madenach, N., Mayer, B., Nam, C., Naumann, A., Peters, K., Poll, S., Quaas, J., Röber, N., Rochetin, N., Rybka, H., Scheck, L., Schemann, V., Schnitt, S., Seifert, A., Senf, F., Shapkalijevski, M., Simmer, C., Singh, S., Sourdeval, O., Spickermann, D., Strandgren, J., Tessiot, O., Vercauteren, N., Vial, J., Voigt, A. & Zängl, G. (2020). The added value of large-eddy and storm-resolving models for simulating clouds and precipitation. Journal of the Meteorological Society of Japan, 98, 395-435. doi:10.2151/jmsj.2020-021


Prof. Dr. Bjorn Stevens
Max Planck Institute for Meteorology
Phone: +49 (0) 40 41173 422 (Assistant Angela Gruber)
Email: bjorn.stevens@we dont want