Arctic System Science: Advances in the Past Two Decades, Expectations for the Next Two Decades

It appears that the concept of the ARCSS program grew from a series of workshops convened in 1988. We can now look back with pride on the tremendous advances that have been achieved over the past two decades in our understanding of the arctic system. Much of arctic research completed before 1990 was driven by either by consideration of resource development or cold war concerns. This research was largely disciplinary in nature, focusing upon exploration and discovery, primarily through surveys and stock assessments. However, the visionary scientists who urged for a more holistic perspective recognized that the components of the arctic system are very tightly coupled, and a change in one part of the system will affect many other components. We began to understand that predictability is not possible through disciplinary studies only, and requires a system-level understanding of the Arctic.

We will examine some of the notable achievements in Arctic System Science over the past two decades and describe possible paths forward to advance the science in the coming years. Notable achievements include:

-Success of large observation and process studies, aimed at collecting atmospheric and surface flux data over annual cycles for the Arctic Ocean and terrestrial regions, which provided data leading to improved models and process understanding.

-Recognition of the complexity of coupled atmospheric and oceanic processes driving the observed sharp downward trend in summer arctic sea ice extent, and that the impending transitioning to a seasonal ice cover will have cascading impacts on climate and marine ecosystems.

-Improved numerical and conceptual models of couplings between the arctic atmosphere, sea ice cover, ocean, and land surface; leading to better appreciation and quantification of system feedbacks.

-Documentation of the sensitivity of the arctic permafrost regime to both observed and expected climate change, and the intimate connections between permafrost dynamics, ecosystem processes, local water and energy balances and the arctic carbon cycle.

-Understanding the behavior and climatic impacts of atmospheric modes, including the Arctic Oscillation, the Pacific Decadal Oscillation and Arctic Dipole anomaly.

-Increased recognition of the importance of understanding the Arctic as a coupled social-ecological system linked by human impacts on the environment and ecosystems and by ecosystem services on which society depends.