Improving future predictions of Arctic sea ice and impact of a changing Arctic on the ocean, atmosphere and ecosystem

参与政府间气候变化专门委员会第四和第五次评估报告(IPCC-AR4/5)的全球气候模型(GCM)显示，向夏季无冰北极的过渡 可能会突然发生，也可能比之前预期的要早。与卫星记录(1979-2006年)相比，所有AR5模型仍然低估了海冰面积的下降，这一事实表明， 然而，在我们对北极气候系统的理解中，这一点是缺乏的。这项工作的总体目标是：1--改进对北冰洋及其周边海域未来海冰状况的预测；2--确定/研究导致海冰减少的海洋、海冰和大气过程；3--研究这种变化对大气环流模式和依赖海冰为生的野生动物的影响。这项工作的具体目标是量化GCM中对海冰质量平衡很重要的小规模过程。在这个方案中，我们特别强调了海冰(铅表示)、垂直海洋热通量(通过平流和湍流混合)和大气边界层过程(即(Mis)表示气体层模式中的地面反转及其对云和地面的影响)。 辐射平衡)。北极气候变化的影响将主要集中在海冰消退对风暴路径和降水模式的影响，以及气候变化的地理变化和时间。 依赖冰的物种栖息地的变化。这项工作的完成将导致1-更好地限制未来北极气候变化的预测，2-更好地理解对海冰质量平衡有重大影响的小尺度海洋和大气边界层过程，以及3-正在全球气候模式和加拿大环境部业务预报模式中实施的海冰模式的更有效的数值求解器。这项研究计划将使加拿大处于一个独特的位置，以更好地评估不断变化的北极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生活方式，他们的生活方式与冰的存在密切相关。

Global Climate Models (GCMs) participating in the Intergovernmental Panel on Climate Change - fourth and fifth Assessment Report (IPCC-AR4/5) show that transition to a summertime ice-free Arctic could occur both abruptly and earlier than previously anticipated. The fact that all AR5 models still underestimate the decline in sea-ice extent as compared to the satellite record (1979-2006) suggests, however, that something in our understanding of the Arctic climate system is lacking. The overall objective of the work is to 1- improve the forecast of future sea ice conditions in the Arctic Ocean and its peripheral Seas, 2- identify/study oceanic, sea ice and atmospheric processes responsible for the sea ice decline, and 3- study the impact of such changes on atmospheric circulation patterns and wildlife that depends on the sea ice for their livelihood. The specific objective of the work is to quantify small scale processes in GCMs that are important in the sea ice mass balance. In this proposal we place special emphasis on the sea ice (lead representation), vertical ocean heat fluxes (through both advection and turbulent mixing), and atmospheric boundary layer processes (i.e. (mis)representation of the surface inversion in GCMs and its impact on clouds and the surface radiative balance). The impact of Arctic climate change will focus primarily on the effect of retreating sea ice on storm tracks and precipitation patterns, and the geographical changes and timing of changes in habitat for ice-dependent species. The completion of this work will lead to 1- better constraints on projection of future Arctic climate change, 2- a better understanding of small scales oceanic and atmospheric boundary layer processes having a strong impact on the sea ice mass balance, and 3- still more efficient numerical solver for the sea-ice models that are being implemented in Global Climate Models and operational forecasts models from Environment Canada. This research program will 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 local Inuit population, whose lifestyle is intimately linked with the presence of ice.