Exploring the role of sea ice physics in Arctic climate variability and predictability

最近观察到的北极变化已经成为全球气候变化的“典型代表”，特别是因为夏季海冰范围在过去35年中迅速缩小。海冰的消退导致了跨北极航运的增长，以及从海底提取矿物和化石燃料的计划。近年来，随着新卫星从太空测量海冰特性，对北极的观测也有所改善。特别是，这些卫星现在提供了冬季北极海冰厚度的估计。这一发展使我们能够更好地监测海冰的状态，并以新的方式测试和评估我们的物理理解和最新的气候模型模拟。政府间气候变化专门委员会（气候专委会）的最新评估得出结论，假设温室气体排放继续增加，到2050年北极可能会可靠地成为无冰地区。然而，IPCC使用的气候模拟往往无法真实地捕捉北极海冰的大尺度特性，如范围、变异性和近期趋势。因此，迫切需要改进北极海冰的模拟，以更好地了解最近观察到的变化和对未来的可信预测，帮助评估风险和机会，并为关于适应和减缓的重要政策决定提供信息。此外，越来越需要更短期的海冰预报，例如提前几周或几个月，以帮助当地社区和航运公司等行业利益攸关方了解情况。该项目将力求更好地了解自然天气和气候波动在产生北极海冰年度至十年时间尺度近期变化方面的作用，改进气候模型模拟的一个基本要素是更好地反映最新海冰模型中缺失的相关物理过程。该提案将为海冰模型开发和实施改进的物理学，该模型已被包括气象局在内的许多国际组织使用。增强的海冰模型将得到进一步发展，以改进其对北极气候的模拟，其提供更可靠的海冰预测的能力也将得到测试。

Recent observed changes in the Arctic have become a 'poster child' for global climatic changes, particularly because the summer sea ice extent has shrunk rapidly over the past 35 years. This retreat of the sea ice has led to growth of trans-Arctic shipping and plans to extract minerals and fossil fuels from the ocean floor. Observations of the Arctic have also improved in recent years with new satellites measuring sea ice properties from space. In particular, these satellites now provide estimates of the sea ice thickness across the Arctic during the winter months. This development allows better monitoring of the state of the sea ice and a new way to test and assess our physical understanding and the latest climate model simulations. The latest assessment of the Intergovernmental Panel on Climate Change (IPCC) concluded that it was likely that the Arctic would become reliably ice-free by 2050 assuming greenhouse gas emissions continue to increase. This change would provide both enormous risks and opportunities.However, the climate simulations used by the IPCC often fail to realistically capture large scale properties of the Arctic sea ice, such as the extent, variability and recent trends. Therefore, there is a key need to improve simulations of Arctic sea ice to provide better understanding of the recent observed changes and credible projections of the future to help assess risks and opportunities and inform important policy decisions about adaptation and mitigation. In addition, there is a growing need for shorter-term sea ice forecasts, such as a few weeks or months ahead, to help inform local communities and industry stakeholders, such as shipping companies. This project will seek to better understand the role of natural weather and climate fluctuations in producing recent Arctic sea ice changes on annual to decadal timescales.One essential ingredient for improving the climate model simulations is to better represent the missing relevant physical processes in the latest sea ice models. This proposal will develop and implement improved physics for the sea ice model, which is used by many international groups, including the Met Office. The enhanced sea ice model will be further developed to improve its simulation of Arctic climate, and its ability to provide more reliable sea ice predictions will also be tested.