Los Alamos Sea Ice Model

Los Alamos Sea Ice Model. It is a sophisticated, high-resolution numerical model developed to simulate the complex physical processes of sea ice within the global climate system. As a key component of major Earth system models, including the Community Earth System Model, it provides critical data for understanding polar climate dynamics and projecting future changes in the Arctic and Antarctic. The model's development is led by scientists at the Los Alamos National Laboratory, leveraging the institution's expertise in computational physics and applied mathematics.

● Overview

The Los Alamos Sea Ice Model represents a state-of-the-art tool for simulating the thermodynamics and dynamics of sea ice cover. It is designed to operate within coupled ocean-atmosphere model frameworks, exchanging data with components like the Parallel Ocean Program and the Community Atmosphere Model. Its primary function is to calculate the evolution of ice thickness, concentration, and movement in response to atmospheric forcing and oceanic heat flux. The model's algorithms account for complex interactions, such as brine rejection during ice formation and the role of snow cover in modulating surface albedo.

● Model components

The model's architecture is built around several core modules that simulate distinct physical processes. The thermodynamic module solves energy balance equations to predict ice growth and melt, incorporating effects from solar radiation and longwave radiation. The dynamic module calculates ice velocity and deformation using a viscous-plastic rheology, which describes the ice as a continuous material that can flow and fracture. Another critical component is the ridging parameterization, which estimates the formation of pressure ridges when ice floes converge. The model also includes a detailed treatment of the ice-ocean boundary layer, simulating the exchange of salt, heat, and momentum.

● Development and history

Initial development began in the late 1990s, building upon earlier concepts from the Cavitating Fluid model. Key figures in its creation include Elizabeth Hunke and William Lipscomb, who published foundational papers in the Journal of Geophysical Research. The model was integrated into the National Center for Atmospheric Research's Climate System Model in the early 2000s, marking its entry into mainstream climate science. Subsequent versions, often referred to by their release tags like CICE4 and CICE5, have introduced major advancements such as improved melt pond physics and a more sophisticated elastic-viscous-plastic dynamics solver. Development is supported by agencies including the U.S. Department of Energy and the National Science Foundation.

● Applications and impact

The model is extensively used for projecting future sea ice extent under scenarios from the Intergovernmental Panel on Climate Change. Its simulations inform major assessments like the Arctic Climate Impact Assessment and are cited in reports from the World Climate Research Programme. Operational applications include providing boundary conditions for weather forecasting models used by the National Oceanic and Atmospheric Administration and the European Centre for Medium-Range Weather Forecasts. Research using the model has been pivotal in studies of the Arctic amplification phenomenon and the potential for increased maritime traffic through the Northern Sea Route. It also supports planning for scientific expeditions, such as those conducted during the International Polar Year.

● Model evaluation and validation

The model's performance is rigorously tested against a wide array of observational data. This includes satellite measurements from missions like ICESat and CryoSat-2, which provide data on ice thickness, and sensors on the Terra satellite that monitor ice concentration. Validation also utilizes in-situ data from field campaigns such as the Surface Heat Budget of the Arctic Ocean project and autonomous platforms like Ice-Tethered Profilers. Model intercomparison projects, notably the Sea Ice Model Intercomparison Project organized under the Climate and Cryosphere project, benchmark its output against other leading models like those from the Max Planck Institute for Meteorology and the Met Office. These evaluations are published in journals including The Cryosphere and Geophysical Research Letters.

Category:Climate modeling Category:Scientific simulation software Category:Los Alamos National Laboratory