Modeling the response of the physical and biological systems of the Arctic to climate change

2007年是北极夏季海冰面积的最低记录，比2005年的历史最低记录减少了20%，面积比安大略还大。这是自70年代末以来每十年冰面积减少8%以上的长期趋势的一部分。PI及其同事参加了最新的政府间气候变化专门委员会（IPCC），对全球气候模型的模拟结果进行了分析，结果表明，北极可能在2040年左右没有冰，并且向夏季无冰北极的过渡可能会迅速发生，即，在几年的时间里。IPCC中60%的全球气候模型也显示了北极向无冰的突然转变。虽然它们大多显示了突然的转变，但与卫星记录（1979 - 2006年）相比，所有这些模型仍然低估了海冰范围的减少。事实上，许多与观测到的海冰减少有关的过程都发生在小的空间尺度上--目前的气候模型还没有解决。拟议研究计划的主要目标是开发一个高分辨率冰海洋模型1-改善对北极和加拿大北极群岛（CAA）未来海冰状况的预测，2-使用该模型来研究高纬度生态系统对气候条件变化的响应。该研究计划将直接建立在PI参与的现有现场计划的基础上，即，南森-阿蒙森盆地观测系统、加拿大盆地观测系统和加拿大北极浮标计划（由PI领导）。这项工作将提供加拿大沃茨无冰条件的时间轴的更好的理解。这也将使加拿大处于一个独特的地位，可以更好地评估北极的变化，以及它如何影响当地的海洋生态系统、加拿大北极的经济发展以及当地因纽特人的福祉，因纽特人的生活方式与冰的存在密切相关，例如捕鱼、狩猎和运输。

The year 2007 marked a record low in summer sea-ice extent in the Arctic, with 20\% less ice than the previous all-time record minimum of 2005, an area larger than Ontario. This is part of a long-term trend of more than 8\% ice extent decline per decade since the late seventies. Analysis of simulation results from a Global Climate Model by the PI and colleagues, participating in the latest Intergovernmental Panel on Climate Change (IPCC), show that the Arctic could be free of ice around the years 2040, and that the transition to a summer ice-free Arctic could happen rapidly, i.e., over the course of a few years. Sixty percent of all global climate models in IPCC also show abrupt transitions to an ice-free Arctic. While they mostly show abrupt transitions, all these models still underestimate the decline in sea-ice extent as compared to satellite record (1979 -2006). Indeed, many of the relevant processes to the observed sea-ice decline occur on small spatial scales - not resolved in current climate models. The main goal of the proposed research program is to develop a high resolution ice-ocean model 1- to improve prediction of future sea ice conditions in both the Arctic and the Canadian Arctic Archipelago (CAA), and 2- to use this model to study the response of high latitude ecosystems to changing climate conditions. This research program will build directly on existing field initiatives in which the PI is involved, i.e., the Nansen Amundsen Basin Observing System, the Canadian Basin Observing System, and the Canadian Arctic Buoy Program (led by the PI). This work will provide an improved understanding of the timeline for ice-free conditions in Canadian Waters. This will also place Canada in a unique position to better assess the changing Arctic and how it can affect local marine ecosystem, economic development of the Canadian Arctic, and the well-being of local Inuit populations, whose lifestyle is intimately linked with the presence of ice, e.g. fishing, hunting and transportation.