Advanced Observation of Arctic Environmental Change
The effects of Arctic warming are not limited to the Arctic but extend across the globe. However, our understanding of the key processes remains incomplete, including the greenhouse gas emission and absorption sources, the causes of sea ice decline and its impact on marine ecosystems, the retreat of glaciers and ice sheets, sea level rise, and the thawing and degradation of permafrost. This lack of observational data and scientific knowledge also leads to uncertainties in future predictions. To address these gaps, it is crucial to gain a comprehensive understanding of the current state of the Arctic through continuous observation of the atmosphere, ocean, cryosphere and land, as well as promoting international cooperation. Strategic Goal 1 focused on accurately understanding Arctic environmental changes based on field observations by utilizing advanced observation systems.
To achieve this goal, observation systems and satellite algorithms have been developed to improve data accuracy and elucidate the actual conditions in regions and periods that were previously difficult to observe. Furthermore, research using originally developed numerical models and large-scale model simulations proved highly effective, enhancing the reproducibility of environmental changes and leading to the clarification of many important mechanisms.
Notable research achievements include the establishment of the basis for standardization of black carbon (BC) measurements in the Arctic; elucidation of the factors of the Arctic warming in the first half of the 20th century and cooling in the middle of the century; detection of unusually low dissolved oxygen and acidified water in a potentially fishable area of the Pacific-side Arctic Ocean; evaluation of the impacts of riverine heat influx on Arctic sea-ice decline and oceanic/atmospheric warming; development of a model of glacial micro-organisms causing surface darkening and red snow phenomena using a global climate model; and improvement of the prediction accuracy of future changes in permafrost distribution.
What is common among these findings is that the impact of Arctic warming is causing various environmental changes, which are interconnected and triggering new environmental changes. In the process, new feedback mechanisms and phenomena have also been identified. Meanwhile, Arctic warming is expected to persist. Future issues include understanding atmospheric changes caused by ongoing Arctic warming, changes in the marine environment such as sea ice melting, mass loss from the ice sheet and its contribution to sea level rise, and the impact of changes in ecosystems and permafrost thaw on greenhouse gas concentrations. To advance these studies, continuous monitoring and a comprehensive understanding of the current conditions are essential. It is necessary to elucidate the mechanisms within the subprocesses of the components of the Arctic system derived from various observations and incorporate these into numerical models, improving the accuracy of future projections and promoting coordination with adaptation and mitigation strategies.