The Arctic is experiencing changes never before seen in historic times. The physical, chemical, biological, and social components of the Arctic System are interrelated, and therefore a holistic perspective is needed to understand and quantify their connections and predict future system changes. A regional Arctic System Model (ASM) will strengthen our understanding of these components. It will advance scientific investigations and provide a framework for improving predictive capabilities, thereby helping society to prepare for environmental change and its impacts on humans, ecosystems, and the global climate system. It will be a vehicle for harnessing the resources of the many sub-disciplines of Arctic research for the benefit of planners and policymakers.

An ASM will build on previous modeling and observations, and it will benefit from ongoing studies of component models that are in varying stages of development. The initial core model will include atmosphere, ocean, sea ice, and selected land components and will be constructed in a manner that allows investigators to add or exchange components as the ASM project progresses. These will include ice sheets, mountain glaciers, dynamic vegetation, biogeochemistry, terrestrial and marine ecosystems, coastal systems, atmospheric chemistry, and human and social dimension modules.

The core focus of the proposed ASM program will be to understand complexity and adaptation in the Arctic System as well as society’s role and response in the evolution of that system. The program is designed to complement and work with global Earth System Modeling programs to create reliable probabilistic forecasts of the state of the Arctic on seasonal to decadal timescales. Therefore, the modeling program must work toward quantifying and reducing uncertainties related to variability of the Arctic System, uncertainty in the models themselves, and uncertainty in society’s response and adaptation to Arctic change. Basic model development within the ASM program should be focused on improving simulations of the Arctic biosphere and anthroposphere.

The ASM program will require coordination of diverse segments of the research community and support for computing infrastructure and software. The coordination function should be guided by a number of working groups and a scientific steering committee. A central facility will fulfill the functions of a project office, data center, and point of international liaison to be shaped and overseen by the steering committee. Dedicated personnel at this facility should provide documentation, testing, and support for the ASM. Proposals for providing these core functions should be sought at the outset of the program.

The program should be approached in stages to make sure it is meeting the overarching goals mentioned above. Stage One will be to fund small pilot projects that allow researchers to demonstrate the capacity of limited-area coupled models to improve understanding of the role of the Arctic in global environmental change. These projects would use high-resolution, Arctic-focused simulations to understand the physics, chemistry, and biology of the Arctic as it undergoes rapid change. If successful, this stage will be expanded to construct a basic regional ASM climate model core. Stage Two incorporates coupled biogeochemical and ecological components into the ASM. Stage Three targets the coupling of those components least ready for integration into the ASM; these include components related to human interaction with the environment. Each stage requires close interaction between ASM model developers and the global modeling and observation communities, and each should be focused on understanding the Arctic as a complex adaptive system.