SIMIP is an endorsed diagnostic MIP for CMIP6 that defines a list of variables to understand the evolution of sea ice in any experiment using the sea ice model as part of CMIP6.

SIMIP Science

The work of SIMIP is broadly divided into two phases:

Arktisches Meereis in der Framstraße, fotografiert auf der Polarstern-Expedition ARK-XXVII-1 (14. Juni - 15. Juli 2012). Foto: Sebastian Menze, Alfred-Wegener-Institut

1. In the run-up to CMIP6, we have defined a list of sea-ice related variables to be stored from CMIP6 model simulations. These variables allow researchers to analyze the three budgets that govern the evolution of sea ice and its impact on the Earth’s climate system, namely conservation of heat, the momentum balance and tracer conservation. In addition, variables are included that allow for the high frequency analysis of the sea-ice state itself. This list is now part of the official CMIP6 data request.

2. Now that CMIP6 model output  has become available, SIMIP has coordinated an overview paper documenting the Arctic sea ice simulation in CMIP6 models, published as SIMIP Community 2020. An overview paper documenting Antarctic sea ice in CMIP6 has also been published as Roach et al. 2020.

SIMIP continues to coordinate analysis using the new SIMIP requested variables through a number of dedicated sub-groups. These include:

Completed projects

  • Establish best practices for regridding sea ice model output (Nikolay Koldunov & Daniel Senftleben)
  • Develop a long time-series sea ice reanalysis dataset (Axel Schweiger)

Active sub-groups

  • Sea-ice dynamics, in particular analysis of velocity fields, strain variance and maximum shear strength (Bruno Tremblay)
  • Spatio-temporal characteristics of sea ice (Ed Blanchard and Alex Jahn).
  • Sea ice advance and retreat (Julienne Stroeve and Abigail Smith).
  • Radiative feedbacks (Cecilia Bitz and Kyle Armour)
  • Non-radiative feedbacks (François Massonnet and Martin Vancoppenolle)  .
  • Machine learning methods for sea ice analysis, prediction and projection (Neven S. Fuckar)
  • Understanding/constraining sea ice volume and surface energy budgets (Ed Blockley)
  • Snow on sea ice (Alek Petty)
  • Quantifying influence of sea ice internal variability in CMIP5 models (Dirk Olonscheck)
  • Use large ensembles to quantify the limitations and opportunities of using short observational sea ice timeseries (Alexandra Jahn)
  • Developing sea-ice satellite simulators to provide a new perspective on simulated and observed sea ice (Abigail Smith  & Clara Burgard)

If you are interested in joining any of these projects, please get in touch with the leaders of the sub groups as indicated in the brackets.

Note that the deadline for papers to be included in the AR6 report has been extended due to COVID-19. Papers now need to be accepted by January 31 2021. However, the AR6 report authors will need to know about your paper before then to incorporate it into the report if relevant. So please email Dirk a copy of any submitted AR6 relevant sea ice results you expect to be published by the January 31 2021 deadline, so he can make space for those results while revising the sea ice section. Please email all your accepted papers of possible relevance to AR6 to as soon as possible, with copy to Dirk to let him now they are now accepted. Confidentiality is ensured.

Coming soon:

  • List of reported issues related to SIMIP-CMIP6 data

Observation for sea ice model evaluation

SIMIP also works towards a common standard for sea-ice model evaluation. For the time being, we refer to the following to data sources:

  • The National Snow and Ice Data Center (NSIDC) maintains a list of sea-ice related observational records that can be used to analyse the performance of sea-ice model simulations:
  • The NCAR ClimateDataGuide also features some sea ice products (in particular sea ice concentrations), with expert guidance on their properties for some of these data records:

SIMIP Mailing List

To subscribe to the SIMIP mailing list, please send an email to the CliC Office (

SIMIP Leadership

SIMIP co-chairs

Patricia DeRepentigny portrait

Patricia DeRepentigny


Patricia is a postdoctoral researcher at the Université catholique de Louvain (UCLouvain). Her research interests broadly cover climate projections of Arctic sea ice in Earth System models, with the goal of improving our understanding of the multiple drivers of sea ice retreat on seasonal to centennial time scales in the context of forcing uncertainty and the internal variability of the climate system. Before her appointment at UCLouvain, she was an ASP postdoctoral fellow at the National Center for Atmospheric Research.

François Massonnet portrait

François Massonnet


François is a F.R.S.-FNRS Research Associate at the Université catholique de Louvain (UCLouvain). His main research interests lie in the predictability and prediction of Arctic and Antarctic sea ice at sub-seasonal to decadal time scales.  He takes active participation to climate-related dissemination activities in the media and frequently engages with the general public.

Martin Vancoppenolle portrait

Martin Vancoppenolle


Martin is a sea ice scientist at LOCEAN lab, Sorbonne Université, in Paris. His research focuses on sea ice and its interactions with climate, ocean, continental ice and marine biogeochemistry. He uses models, observations and theory. He is co-leading the development of SI3 sea ice model and participates in climate model projections by the IPSL Group. Martin is editor at Journal of Geophysical Research-Oceans and lectures on sea ice in several European universities.

SIMIP Scientific Steering Group

Clare Eayrs portrait

Clare Eayrs

Clare is a Postdoctoral Researcher at the Korea Polar Research Institute. Her research focuses on the interaction between ice, the ocean, and the atmosphere and how changes in the cryosphere affect the global climate. Focusing on West Antarctica, Clare is particularly interested in the Antarctic sea ice seasonal cycle, the marginal ice zone, and the interactions between sea ice and ice sheet margins.

Ed Blockley portrait

Ed Blockley

Ed manages the Polar Climate Group of the Met Office Hadley Centre – a group with considerable experience developing and evaluating coupled climate models and a focus on understanding climate change in polar regions. Ed has experience of ocean and sea ice modelling and assessment within the framework of the Met Office’s global climate models and operational short-range and seasonal forecasting systems. Ed is also currently co-chair of the NEMO Sea Ice Working Group and co-lead of NEMO’s SI3 “Sea Ice modelling Integrated Initiative” sea ice model.

Lettie Roach portrait

Lettie Roach

Lettie is an Associate Research Scientist at the Center for Climate Systems Research, Columbia University based at NASA Goddard Institute for Space Studies (GISS) in New York City. She is broadly interested in Earth’s climate system, with a focus on the polar regions. Her research aims to better understand the physics of coupled interactions between ice and climate. She typically works with climate models of varying levels of complexity, in combination with observations, aiming to improve climate projections.

Alexandra Jahn portrait

Alexandra Jahn

Alexandra is an Associate Professor at the University of Colorado in Boulder, studying Arctic and Paleo climate processes with a focus on the role of sea ice and the ocean in the climate system. She is especially interested in improving comparisons between climate models and observations, and was a co-chair of SIMIP between 2014-2023. In 2022/23, she was an Alexander von Humboldt Fellow in Germany.

Bruno Tremblay portrait

Bruno Tremblay

Bruno is a Professor in McGill’s Department of Atmospheric and Oceanic Sciences. His research focuses on sea-ice dynamics, short-term to seasonal forecast and decadal projection of Arctic ice. He has received several scientific awards including the Storke Doherty Lectureship from Columbia University, the National Oceanic and Atmospheric Administration Postdoctoral Fellowship in Climate and Global Change and the Landolt Chair “Innovations for a Sustainable Future”.

Dirk Notz portrait

Dirk Notz

Dirk is a Professor at Universität Hamburg, Germany. His research focuses on a broad range of topics related to sea ice, including the response of sea ice to climate change, the microstructure of sea ice, internal variability of the polar sea ice cover etc. For his research, he uses and develops a broad range of methods, ranging from in situ and remote sensing observations to conceptual model and Earth System models. Dirk is a lead author on sea ice for the recent IPCC AR6 report. He is very active in the dissemination of climate-change knowledge to the general public and stakeholders.

Alek Petty portrait

Alek Petty

Alek is a polar climate scientist based at the University of Maryland with a background in sea ice model development (e.g. CICE) and remote sensing data analysis (e.g. NASA’s Operation IceBridge and ICESat-2 missions). His current research is focused on improving future projections of polar sea ice using sea ice freeboard and thickness observations as well as data assimilation investigations for assessing current and potential observing systems.

Former SIMIP Co-Chairs and SSG Members (2014-2023)


  • Alexandra Jahn, University of Colorado Boulder
  • Dirk Notz, Universität Hamburg

SSG members:

  • Marika Holland, National Center for Atmospheric Research
  • Elizabeth Hunke, Los Alamos National Laboratory
  • François Massonnet, Université catholique de Louvain
  • Julienne Stroeve, National Snow and Ice Data Center
  • Bruno Tremblay, McGill University
  • Martin Vancoppenolle, LOCEAN Sorbonne Université