Articles | Volume 9, issue 11
Geosci. Model Dev., 9, 4185–4208, 2016

Special issue: Coupled Model Intercomparison Project Phase 6 (CMIP6) Experimental...

Geosci. Model Dev., 9, 4185–4208, 2016

Model experiment description paper 22 Nov 2016

Model experiment description paper | 22 Nov 2016

High Resolution Model Intercomparison Project (HighResMIP v1.0) for CMIP6

Reindert J. Haarsma1, Malcolm J. Roberts2, Pier Luigi Vidale3, Catherine A. Senior2, Alessio Bellucci4, Qing Bao5, Ping Chang6, Susanna Corti7, Neven S. Fučkar8, Virginie Guemas8,23, Jost von Hardenberg7, Wilco Hazeleger1,9,10, Chihiro Kodama11, Torben Koenigk12, L. Ruby Leung13, Jian Lu13, Jing-Jia Luo14, Jiafu Mao15, Matthew S. Mizielinski2, Ryo Mizuta16, Paulo Nobre17, Masaki Satoh18, Enrico Scoccimarro4,22, Tido Semmler19, Justin Small20, and Jin-Song von Storch21 Reindert J. Haarsma et al.
  • 1Weather and Climate modeling, Royal Netherlands Meteorological Institute, De Bilt, the Netherlands
  • 2Met Office Hadley Centre, Exeter, UK
  • 3NCAS-Climate, University of Reading, Reading, UK
  • 4Climate Simulation and Prediction Divsion, Centro Euro-Mediterraneo per i Cambiamenti Climatici, Bologna, Italy
  • 5Institute of Atmospheric Physics, Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Chinese Academy of Sciences, Beijing, China P. R.
  • 6Department of Oceanography, Texas A&M University, College Station, Texas, USA
  • 7Institute of Atmospheric Sciences and Climate, National Research Council, Bologna, Italy
  • 8Earth Sciences, Barcelona Supercomputing Center, Barcelona, Spain
  • 9Netherlands eScience Center, Amsterdam, the Netherlands
  • 10Meteorology and Air Quality, Wageningen University, Wageningen, the Netherlands
  • 11Atmospheric Science, Japan Agency for Marine-Earth Science and Technology, Tokyo, Japan
  • 12Climate Research, Swedish Meteorological and Hydrological Institute, Norrköping, Sweden
  • 13Earth System Analysis and Modeling, Pacific Northwest National Laboratory, Richland, USA
  • 14Climate Dynamics, Bureau of Meteorology, Melbourne, Australia
  • 15Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge,Tennessee, USA
  • 16Climate Research Department, Meteorological Research Institute, Tsukuba, Japan
  • 17Climate Modeling, Instituto Nacional de Pesquisas Espaciais, São José dos Campos, Brazil
  • 18Atmosphere and Ocean Research Institute, The University of Tokyo, Tokyo, Japan
  • 19Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
  • 20Climate and Global Dynamics Divsion, National Center for Atmospheric Research, Boulder, Colorado, USA
  • 21The Ocean in the Earth System, Max-Planck-Institute for Meteorology, Hamburg, Germany
  • 22Sezione di Bologna, Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy
  • 23Meteo-France, Centre National de Recherches Meteorologiques, Toulouse, France

Abstract. Robust projections and predictions of climate variability and change, particularly at regional scales, rely on the driving processes being represented with fidelity in model simulations. The role of enhanced horizontal resolution in improved process representation in all components of the climate system is of growing interest, particularly as some recent simulations suggest both the possibility of significant changes in large-scale aspects of circulation as well as improvements in small-scale processes and extremes.

However, such high-resolution global simulations at climate timescales, with resolutions of at least 50 km in the atmosphere and 0.25° in the ocean, have been performed at relatively few research centres and generally without overall coordination, primarily due to their computational cost. Assessing the robustness of the response of simulated climate to model resolution requires a large multi-model ensemble using a coordinated set of experiments. The Coupled Model Intercomparison Project 6 (CMIP6) is the ideal framework within which to conduct such a study, due to the strong link to models being developed for the CMIP DECK experiments and other model intercomparison projects (MIPs).

Increases in high-performance computing (HPC) resources, as well as the revised experimental design for CMIP6, now enable a detailed investigation of the impact of increased resolution up to synoptic weather scales on the simulated mean climate and its variability.

The High Resolution Model Intercomparison Project (HighResMIP) presented in this paper applies, for the first time, a multi-model approach to the systematic investigation of the impact of horizontal resolution. A coordinated set of experiments has been designed to assess both a standard and an enhanced horizontal-resolution simulation in the atmosphere and ocean. The set of HighResMIP experiments is divided into three tiers consisting of atmosphere-only and coupled runs and spanning the period 1950–2050, with the possibility of extending to 2100, together with some additional targeted experiments. This paper describes the experimental set-up of HighResMIP, the analysis plan, the connection with the other CMIP6 endorsed MIPs, as well as the DECK and CMIP6 historical simulations. HighResMIP thereby focuses on one of the CMIP6 broad questions, “what are the origins and consequences of systematic model biases?”, but we also discuss how it addresses the World Climate Research Program (WCRP) grand challenges.

Short summary
Recent progress in computing power has enabled climate models to simulate more processes in detail and on a smaller scale. Here we present a common protocol for these high-resolution runs that will foster the analysis and understanding of the impact of model resolution on the simulated climate. These runs will also serve as a more reliable source for assessing climate risks that are associated with small-scale weather phenomena such as tropical cyclones.