Articles | Volume 9, issue 9
Geosci. Model Dev., 9, 3427–3446, 2016

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

Geosci. Model Dev., 9, 3427–3446, 2016

Methods for assessment of models 23 Sep 2016

Methods for assessment of models | 23 Sep 2016

The CMIP6 Sea-Ice Model Intercomparison Project (SIMIP): understanding sea ice through climate-model simulations

Dirk Notz1, Alexandra Jahn2, Marika Holland3, Elizabeth Hunke4, François Massonnet5,6, Julienne Stroeve7,8, Bruno Tremblay9, and Martin Vancoppenolle10 Dirk Notz et al.
  • 1Max Planck Institute for Meteorology, Hamburg, Germany
  • 2Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado at Boulder, Boulder, Colorado, USA
  • 3Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, Colorado, USA
  • 4Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
  • 5Earth Sciences Department, Barcelona Supercomputing Center (BSC-CNS), Barcelona, Spain
  • 6Georges Lemaître Centre for Earth and Climate Research, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
  • 7National Snow and Ice Data Center, Boulder, Colorado, USA
  • 8University College London, London, UK
  • 9Department of Atmospheric and Oceanic Sciences, McGill University, Montréal, Canada
  • 10Sorbonne Universités, UPMC Paris 6, LOCEAN-IPSL, CNRS/IRD/MNHN, Paris, France

Abstract. A better understanding of the role of sea ice for the changing climate of our planet is the central aim of the diagnostic Coupled Model Intercomparison Project 6 (CMIP6)-endorsed Sea-Ice Model Intercomparison Project (SIMIP). To reach this aim, SIMIP requests sea-ice-related variables from climate-model simulations that allow for a better understanding and, ultimately, improvement of biases and errors in sea-ice simulations with large-scale climate models. This then allows us to better understand to what degree CMIP6 model simulations relate to reality, thus improving our confidence in answering sea-ice-related questions based on these simulations. Furthermore, the SIMIP protocol provides a standard for sea-ice model output that will streamline and hence simplify the analysis of the simulated sea-ice evolution in research projects independent of CMIP. To reach its aims, SIMIP provides a structured list of model output that allows for an examination of the three main budgets that govern the evolution of sea ice, namely the heat budget, the momentum budget, and the mass budget. In this contribution, we explain the aims of SIMIP in more detail and outline how its design allows us to answer some of the most pressing questions that sea ice still poses to the international climate-research community.

Short summary
The large-scale evolution of sea ice is both an indicator and a driver of climate changes. Hence, a realistic simulation of sea ice is key for a realistic simulation of the climate system of our planet. To assess and to improve the realism of sea-ice simulations, we present here a new protocol for climate-model output that allows for an in-depth analysis of the simulated evolution of sea ice.