CICE

CICE
Name	CICE
Developer	Los Alamos National Laboratory; Oak Ridge National Laboratory; National Center for Atmospheric Research contributors
Initial release	1990s
Repository	Community repositories and institutional archives
Platform	Linux; Unix; macOS
License	Open-source consortium licenses
Website	Community portals and institutional pages

CICE is a sea ice thermodynamics and dynamics model used in coupled climate and ocean systems to simulate the evolution of sea ice, snow, and related processes. It links with major Earth system models and regional modeling frameworks to represent ice mechanics, thermodynamics, albedo, and melt ponds for polar and subpolar simulations. The model interfaces with atmospheric, oceanic, and biogeochemical components in large-scale efforts to study past, present, and future states of the cryosphere.

Overview

CICE provides numerical representations of sea ice processes that are integrated into broader frameworks such as Community Earth System Model, Coupled Model Intercomparison Project, World Climate Research Programme activities, Intergovernmental Panel on Climate Change assessments, European Centre for Medium-Range Weather Forecasts systems. It incorporates parameterizations developed in collaboration with researchers at University of Washington, Scripps Institution of Oceanography, Columbia University (Lamont-Doherty Earth Observatory), University of Colorado Boulder (Cooperative Institute for Research in Environmental Sciences), and University of Cambridge. The codebase is used by operational centers including National Oceanic and Atmospheric Administration, Environment and Climate Change Canada, Met Office, and research institutions such as Plymouth Marine Laboratory. It supports interfaces to coupling frameworks like Earth System Modeling Framework and Open Modeling Interface implementations. CICE output fields are commonly analyzed alongside datasets from ICEsat, CryoSat-2, MODIS, AMSRE, and Arctic Regional Ocean Observing System.

History and Development

The model traces its lineage to sea ice models developed at Los Alamos National Laboratory in the 1990s and was extended through collaborations with Naval Postgraduate School, University of Washington, University of California, Santa Cruz, and Woods Hole Oceanographic Institution. Major developmental milestones correspond with participation in projects like World Climate Research Programme model intercomparisons and contributions to the Coupled Model Intercomparison Project Phase 5 and Phase 6 experiments that informed Intergovernmental Panel on Climate Change reports. Over time, enhancements were driven by observational programs such as Arctic Ocean Experiment and initiatives including National Snow and Ice Data Center campaigns, POLARCAT, and NSF Arctic Research. Funding and coordination have involved agencies like Department of Energy (United States), Natural Environment Research Council, and European Commission research calls. The community has transitioned from single-institution stewardship to distributed development with governance modeled on consortium practices used by Software Carpentry and GitHub-hosted projects.

Architecture and Modeling Components

CICE is structured into modules covering thermodynamics, dynamics, ridging, sea ice thickness distributions, melt pond schemes, albedo, and biogeochemical tracers. Thermodynamic schemes draw on parameterizations from studies at Scott Polar Research Institute, Alfred Wegener Institute, and University of Bergen. Dynamics modules implement viscous-plastic and elastic-viscous-plastic rheologies used in models by Los Alamos National Laboratory, Geophysical Fluid Dynamics Laboratory, and Princeton University. Ridging and floe fragmentation parameterizations reference laboratory and field work conducted by Scripps Institution of Oceanography and Lamont-Doherty Earth Observatory. Melt pond representation integrates approaches evaluated in studies from University of Washington and University of Alaska Fairbanks. Coupling interfaces enable exchange with ocean components such as Parallel Ocean Program, Nucleus for European Modelling of the Ocean, Regional Ocean Modeling System, and atmosphere components like Community Atmosphere Model and ECMWF Integrated Forecast System. I/O and workflow integration aligns with community tools including NetCDF, MPI, CIME, and ESMF libraries.

Applications and Use Cases

CICE is applied in global climate projections undertaken by centers contributing to Coupled Model Intercomparison Project, regional Arctic and Antarctic forecasting at European Polar Board partners, operational sea ice forecasting at National Snow and Ice Data Center and Canadian Ice Service, and paleoceanographic reconstructions tied to Paleoclimate Modelling Intercomparison Project. It supports studies of coupled feedbacks involving Atlantic Meridional Overturning Circulation, El Niño–Southern Oscillation, Arctic amplification, and interactions with ecosystems studied by Monterey Bay Aquarium Research Institute and Alaska Fisheries Science Center. Applications include search-and-rescue and navigation support using outputs similar to those produced for International Maritime Organization guidelines, assessments for United Nations Framework Convention on Climate Change reporting, and impact studies informing Coastal Zone Management and National Adaptation Plans.

Validation and Performance

Model validation uses satellite missions such as ICESat, CryoSat-2, Sentinel-1, and MODIS, in situ campaigns by Barrow (Utqiaġvik) observatories, ice-tethered profiler programs from British Antarctic Survey, and shipboard measurement programs coordinated by U.S. Coast Guard and Healy expeditions. Intercomparison studies reference protocols from Global Energy and Water Exchanges and metrics established by World Meteorological Organization panels. Performance optimization draws on high-performance computing facilities at Oak Ridge National Laboratory (Summit), National Energy Research Scientific Computing Center, Argonne National Laboratory (Aurora initiatives), and uses tools from OpenMP, CUDA research collaborations, and community benchmarking exercises like ACME.

Community and Governance

Development and user support are organized through workshops and governance structures involving stakeholders from Los Alamos National Laboratory, Oak Ridge National Laboratory, National Center for Atmospheric Research, University of Washington, Scripps Institution of Oceanography, Environment and Climate Change Canada, Met Office, and other partners. Community code sprints, tutorials, and user forums are hosted at meetings associated with American Geophysical Union, European Geosciences Union, Society of Industrial and Applied Mathematics, and project-specific symposia. Contribution practices follow open-source norms similar to those used by NumFOCUS and collaborative infrastructures like GitHub and GitLab for issue tracking, continuous integration, and release management.

Category:Sea ice models