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

2007年标志着北极夏季海冰面积创历史新低，冰层比2005年创下的最低纪录少了20%，面积比安大略省还大。这是自70年代末以来冰川面积每十年下降8%以上的长期趋势的一部分。参与最新政府间气候变化专门委员会(IPCC)的PI及其同事对全球气候模型模拟结果的分析表明，北极可能在2040年左右实现无冰，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。政府间气候变化专门委员会的所有全球气候模型中，60%也显示出向无冰北极的突然过渡。虽然它们大多显示出突变，但与卫星记录(1979-2006年)相比，所有这些模型仍然低估了海冰面积的下降。事实上，许多与观测到的海冰减少相关的过程发生在小空间尺度上--目前的气候模型没有解决这一问题。拟议研究计划的主要目标是开发一个高分辨率的冰-海洋模式1--改进对北极和加拿大北极群岛(CAA)未来海冰状况的预测，以及2--利用该模式研究高纬度生态系统对气候条件变化的反应。这项研究计划将直接建立在国际和平研究所参与的现有实地倡议的基础上，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(由国际和平研究所牵头)。这项工作将提供对加拿大水域无冰条件时间表的更好理解。这也将使加拿大处于独特的地位，可以更好地评估不断变化的北极及其如何影响当地海洋生态系统、加拿大北极的经济发展以及当地因纽特人的福祉，他们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.