Projections of an Ice-Diminished Arctic Ocean

近年来，北极气候发生了显著变化。最显著的变化之一是海冰减少，同时大气环流发生变化，地表气温升高。 正如全球气候模型（GCM）预测的那样，这种北极变暖趋势可能会持续下去，导致北极海冰覆盖面积减少。 冰盖的减少将对区域和全球气候以及北极地区的社会经济和生态系统产生重大影响。重要的是要了解北极系统过去所经历的变化，并预测它在未来将如何演变。主要研究人员将使用海洋和海冰耦合模型对北极冰-海洋系统进行回顾性调查和未来预测。该模型是全球性的;其网格强调北冰洋及其与亚北冰洋的联系。他们将调查北冰洋和邻近海域的历史和当代变化，并预测在各种可能的变暖情景下与北极冰盖减少相关的未来变化。有两个科学目标：1）研究北极系统的历史演变，了解近几十年来海冰和上层海洋发生的变化，2）预测未来变暖情景中北极海冰覆盖的减少，并研究冰减少的北冰洋和邻近海域的大气强迫，海冰过程和海洋过程之间的关键联系。该项目将分两个阶段进行：回顾性调查和多情景未来预测。在第一阶段，主要研究人员将解释过去五十年来海冰和北冰洋上部发生的大规模变化。在第二阶段，他们将定性和定量地研究北极冰盖在未来何时、何地、在何种情况下可能减少或消失。他们还将研究冰枯竭的北冰洋海洋环流和过程的变化及其与亚北冰洋的相互作用。 回顾性调查补充和扩展了其他使用有限领域区域模型的北极气候变化调查。未来北冰洋冰减少的预测补充了GCM对可能的全球变暖的预测，并对北极产生影响。 这项工作将为多机构北极环境变化研究做出重要贡献，以了解过去几十年来发生的大规模北极环境变化，并评估未来可能发生的变化。 更广泛的影响：这项工作的性质，解释北极系统的历史和当代变化，预测未来趋势及其与世界其他海洋的关键联系，对科学，社会和政策制定至关重要。 研究人员和公众将通过档案网页获得结果。对海冰覆盖范围缩小的系统预测将有助于对北极的地球化学和生态系统变化进行科学研究。对未来冰盖的范围、厚度和持续时间的了解将对北极和亚北极地区人民的生计产生影响。 主要研究者将提供有关可航行性、运输季节长度等的信息，沿着北方航道和西北航道以及目前季节性通航并可能变得更容易通航的其他北极地区，对北极地区的经济活动产生巨大影响。

ABSTRACTOPP-2040916ZhangSignificant changes in arctic climate have been detected in recent years. One of the most striking changes is the decline of sea ice concurrent with changes in atmospheric circulation and increased surface air temperature. This arctic warming trend is likely to continue, as projected by global climate models (GCMs), leading to a diminished arctic sea-ice cover. Diminution of ice cover will have a significant impact on the regional and global climate, and on the socio-economics and ecosystems in the north polar region. It is important to understand the changes that the arctic system has undergone in the past and predict how it will evolve in the future. The Principal Investigators will use a coupled ocean and sea ice model to conduct a retrospective investigation and future projections of the arctic ice-ocean system. The model is global; its grid emphasizes the Arctic Ocean and its linkages to the subarctic oceans. They will investigate the historical and contemporary changes of the Arctic Ocean and the adjacent seas, and to project future changes that are associated with a diminished arctic ice cover under various plausible warming scenarios. There are two science goals: 1) to examine the historical evolution of the arctic system and to understand changes that have occurred in sea ice and the upper ocean in recent decades, and 2) to project a diminished arctic sea-ice cover in future warming scenarios and to examine key linkages among atmospheric forcing, sea-ice processes, and oceanic processes in an ice-diminished Arctic Ocean and the adjacent seas. The project will be done in two-stages: a retrospective investigation, and multiscenario future projections. In the first stage, the Principal Investigators will interpret the large-scale changes that have occurred in sea ice and the upper Arctic Ocean over the past five decades. In the second stage, they will qualitatively and quantitatively examine when, where, and under what circumstances the arctic ice cover is likely to diminish or disappear in the future. They will also study changes in oceanic circulation and processes in an ice-depleted Arctic Ocean and in its interactions with the subarctic oceans. The retrospective investigation complements and expands on other investigations of arctic climate change that use regional models with a limited domain. The future projections of an ice-diminished Arctic Ocean complement GCM projections of possible global warming with Arctic implications. This work will make important contributions to the multi-agency Study of Environmental Arctic Change (SEARCH) effort to understand the large-scale arctic environmental changes that have occurred in the last several decades and to assess possible future changes. Broader Impact: The nature of the work, interpreting the historical and contemporary changes and projecting future trends in the arctic system and its key linkages with the rest of the world ocean, is essential to science, society, and policy formulation. The results will be accessible to researchers and the general public through archival Web pages. The systematic predictions of a retreating sea-ice cover will facilitate scientific studies on biogeochemical and ecosystem changes in the Arctic. Knowledge of the extent, thickness, and duration of the ice cover in the future will have an impact on the livelihood of arctic and subarctic people. The Principal Investigators will provide information about navigability, length of shipping seasons, etc., along the Northern Sea Route and the Northwest Passage and in other arctic areas that are presently seasonally navigable and may become more easily navigable, with a huge impact on economic activities in the north polar region.